update code dealing with snd_dbuf objects to do so using a functional interface

modify chn_setblocksize() to pick a default soft-blocksize appropriate to the
sample rate and format in use.  it will aim for a power of two size small
enough to generate block sizes of at most 20ms.  it will also set the
hard-blocksize taking into account rate/format conversions in use.

update drivers to implement setblocksize  correctly:
updated, tested: 	sb16, emu10k1, maestro, solo
updated, untested: 	ad1816, ess, mss, sb8, csa
not updated: 		ds1, es137x, fm801, neomagic, t4dwave, via82c686

i lack hardware to test: ad1816, csa, fm801, neomagic
others will be updated/tested in the next few days.

24 files changed, 638 insertions, 400 deletions

diff --git a/sys/dev/sound/isa/ad1816.c b/sys/dev/sound/isa/ad1816.c
index d6e1dd7..f83aafb 100644
--- a/sys/dev/sound/isa/ad1816.c
+++ b/sys/dev/sound/isa/ad1816.c
@@ -39,7 +39,7 @@ struct ad1816_chinfo {
 	struct ad1816_info *parent;
 	pcm_channel *channel;
 	snd_dbuf *buffer;
-	int dir;
+	int dir, blksz;
 };
 
 struct ad1816_info {
@@ -131,12 +131,12 @@ ad1816_intr(void *arg)
 		c &= AD1816_INTRCI | AD1816_INTRPI;
     	}
     	/* check for capture interupt */
-    	if (ad1816->rch.buffer->dl && (c & AD1816_INTRCI)) {
+    	if (sndbuf_runsz(ad1816->rch.buffer) && (c & AD1816_INTRCI)) {
 		chn_intr(ad1816->rch.channel);
 		served |= AD1816_INTRCI;		/* cp served */
     	}
     	/* check for playback interupt */
-    	if (ad1816->pch.buffer->dl && (c & AD1816_INTRPI)) {
+    	if (sndbuf_runsz(ad1816->pch.buffer) && (c & AD1816_INTRPI)) {
 		chn_intr(ad1816->pch.channel);
 		served |= AD1816_INTRPI;		/* pb served */
     	}
@@ -311,8 +311,7 @@ ad1816chan_init(kobj_t obj, void *devinfo, snd_dbuf *b, pcm_channel *c, int dir)
 	ch->parent = ad1816;
 	ch->channel = c;
 	ch->buffer = b;
-	ch->buffer->bufsize = DSP_BUFFSIZE;
-	if (chn_allocbuf(ch->buffer, ad1816->parent_dmat) == -1) return NULL;
+	if (sndbuf_alloc(ch->buffer, ad1816->parent_dmat, DSP_BUFFSIZE) == -1) return NULL;
 	return ch;
 }
 
@@ -322,8 +321,7 @@ ad1816chan_setdir(kobj_t obj, void *data, int dir)
 	struct ad1816_chinfo *ch = data;
   	struct ad1816_info *ad1816 = ch->parent;
 
-	ch->buffer->chan = rman_get_start((dir == PCMDIR_PLAY)?
-		ad1816->drq1 : ad1816->drq2);
+	sndbuf_isadmasetup(ch->buffer, (dir == PCMDIR_PLAY)? ad1816->drq1 : ad1816->drq2);
 	ch->dir = dir;
 	return 0;
 }
@@ -384,7 +382,10 @@ ad1816chan_setspeed(kobj_t obj, void *data, u_int32_t speed)
 static int
 ad1816chan_setblocksize(kobj_t obj, void *data, u_int32_t blocksize)
 {
-	return blocksize;
+	struct ad1816_chinfo *ch = data;
+
+	ch->blksz = blocksize;
+	return ch->blksz;
 }
 
 static int
@@ -397,14 +398,14 @@ ad1816chan_trigger(kobj_t obj, void *data, int go)
 	if (go == PCMTRIG_EMLDMAWR || go == PCMTRIG_EMLDMARD)
 		return 0;
 
-	buf_isadma(ch->buffer, go);
+	sndbuf_isadma(ch->buffer, go);
     	wr = (ch->dir == PCMDIR_PLAY);
     	reg = wr? AD1816_PLAY : AD1816_CAPT;
     	switch (go) {
     	case PCMTRIG_START:
 		/* start only if not already running */
 		if (!(io_rd(ad1816, reg) & AD1816_ENABLE)) {
-	    		int cnt = ((ch->buffer->dl) >> 2) - 1;
+	    		int cnt = ((ch->blksz) >> 2) - 1;
 	    		ad1816_write(ad1816, wr? 8 : 10, cnt); /* count */
 	    		ad1816_write(ad1816, wr? 9 : 11, 0); /* reset cur cnt */
 	    		ad1816_write(ad1816, 1, ad1816_read(ad1816, 1) |
@@ -441,7 +442,7 @@ static int
 ad1816chan_getptr(kobj_t obj, void *data)
 {
 	struct ad1816_chinfo *ch = data;
-	return buf_isadmaptr(ch->buffer);
+	return sndbuf_isadmaptr(ch->buffer);
 }
 
 static pcmchan_caps *
diff --git a/sys/dev/sound/isa/ess.c b/sys/dev/sound/isa/ess.c
index f353289..b9c8362 100644
--- a/sys/dev/sound/isa/ess.c
+++ b/sys/dev/sound/isa/ess.c
@@ -82,7 +82,7 @@ struct ess_chinfo {
 	pcm_channel *channel;
 	snd_dbuf *buffer;
 	int dir, hwch, stopping, run;
-	u_int32_t fmt, spd;
+	u_int32_t fmt, spd, blksz;
 };
 
 struct ess_info {
@@ -358,7 +358,7 @@ ess_intr(void *arg)
 			printf("ess: play intr while not running\n");
 		if (sc->pch.stopping) {
 			sc->pch.run = 0;
-			buf_isadma(sc->pch.buffer, PCMTRIG_STOP);
+			sndbuf_isadma(sc->pch.buffer, PCMTRIG_STOP);
 			sc->pch.stopping = 0;
 			if (sc->pch.hwch == 1)
 				ess_write(sc, 0xb8, ess_read(sc, 0xb8) & ~0x01);
@@ -373,7 +373,7 @@ ess_intr(void *arg)
 			printf("ess: record intr while not running\n");
 		if (sc->rch.stopping) {
 			sc->rch.run = 0;
-			buf_isadma(sc->rch.buffer, PCMTRIG_STOP);
+			sndbuf_isadma(sc->rch.buffer, PCMTRIG_STOP);
 			sc->rch.stopping = 0;
 			/* XXX: will this stop audio2? */
 			ess_write(sc, 0xb8, ess_read(sc, 0xb8) & ~0x01);
@@ -509,7 +509,7 @@ ess_start(struct ess_chinfo *ch)
 	struct ess_info *sc = ch->parent;
     	int play = (ch->dir == PCMDIR_PLAY)? 1 : 0;
 
-	ess_setupch(sc, ch->hwch, ch->dir, ch->spd, ch->fmt, ch->buffer->dl);
+	ess_setupch(sc, ch->hwch, ch->dir, ch->spd, ch->fmt, ch->blksz);
 	ch->stopping = 0;
 	if (ch->hwch == 1)
 		ess_write(sc, 0xb8, ess_read(sc, 0xb8) | 0x01);
@@ -547,14 +547,13 @@ esschan_init(kobj_t obj, void *devinfo, snd_dbuf *b, pcm_channel *c, int dir)
 	ch->parent = sc;
 	ch->channel = c;
 	ch->buffer = b;
-	ch->buffer->bufsize = ESS_BUFFSIZE;
-	if (chn_allocbuf(ch->buffer, sc->parent_dmat) == -1)
+	if (sndbuf_alloc(ch->buffer, sc->parent_dmat, ESS_BUFFSIZE) == -1)
 		return NULL;
 	ch->dir = dir;
 	ch->hwch = 1;
 	if ((dir == PCMDIR_PLAY) && (sc->duplex))
 		ch->hwch = 2;
-	ch->buffer->chan = rman_get_start((ch->hwch == 1)? sc->drq1 : sc->drq2);
+	sndbuf_isadmasetup(ch->buffer, (ch->hwch == 1)? sc->drq1 : sc->drq2);
 	return ch;
 }
 
@@ -584,7 +583,10 @@ esschan_setspeed(kobj_t obj, void *data, u_int32_t speed)
 static int
 esschan_setblocksize(kobj_t obj, void *data, u_int32_t blocksize)
 {
-	return blocksize;
+	struct ess_chinfo *ch = data;
+
+	ch->blksz = blocksize;
+	return ch->blksz;
 }
 
 static int
@@ -598,7 +600,7 @@ esschan_trigger(kobj_t obj, void *data, int go)
 	switch (go) {
 	case PCMTRIG_START:
 		ch->run = 1;
-		buf_isadma(ch->buffer, go);
+		sndbuf_isadma(ch->buffer, go);
 		ess_start(ch);
 		break;
 
@@ -616,7 +618,7 @@ esschan_getptr(kobj_t obj, void *data)
 {
 	struct ess_chinfo *ch = data;
 
-	return buf_isadmaptr(ch->buffer);
+	return sndbuf_isadmaptr(ch->buffer);
 }
 
 static pcmchan_caps *
diff --git a/sys/dev/sound/isa/mss.c b/sys/dev/sound/isa/mss.c
index 3c6a126..a1802d4 100644
--- a/sys/dev/sound/isa/mss.c
+++ b/sys/dev/sound/isa/mss.c
@@ -48,7 +48,7 @@ struct mss_chinfo {
 	pcm_channel *channel;
 	snd_dbuf *buffer;
 	int dir;
-	u_int32_t fmt;
+	u_int32_t fmt, blksz;
 };
 
 struct mss_info {
@@ -67,7 +67,6 @@ struct mss_info {
 
     char mss_indexed_regs[MSS_INDEXED_REGS];
     char opl_indexed_regs[OPL_INDEXED_REGS];
-    int pdma, rdma;
     int bd_id;      /* used to hold board-id info, eg. sb version,
 		     * mss codec type, etc. etc.
 		     */
@@ -242,19 +241,17 @@ mss_release_resources(struct mss_info *mss, device_t dev)
 				     mss->irq);
 		mss->irq = 0;
     	}
-    	if (mss->drq1) {
-		bus_release_resource(dev, SYS_RES_DRQ, mss->drq1_rid,
-				     mss->drq1);
-		mss->drq1 = 0;
-		mss->pdma = -1;
-    	}
-    	if (mss->drq2) {
+    	if (mss->drq2 && mss->drq2 != mss->drq1) {
 		bus_release_resource(dev, SYS_RES_DRQ, mss->drq2_rid,
 				     mss->drq2);
 		mss->drq2 = 0;
-		mss->rdma = -1;
     	}
-    	if (mss->io_base) {
+     	if (mss->drq1) {
+		bus_release_resource(dev, SYS_RES_DRQ, mss->drq1_rid,
+				     mss->drq1);
+		mss->drq1 = 0;
+    	}
+   	if (mss->io_base) {
 		bus_release_resource(dev, SYS_RES_IOPORT, mss->io_rid,
 				     mss->io_base);
 		mss->io_base = 0;
@@ -274,7 +271,7 @@ mss_release_resources(struct mss_info *mss, device_t dev)
 static int
 mss_alloc_resources(struct mss_info *mss, device_t dev)
 {
-    	int ok = 1;
+    	int pdma, rdma, ok = 1;
 	if (!mss->io_base)
     		mss->io_base = bus_alloc_resource(dev, SYS_RES_IOPORT, &mss->io_rid,
 						  0, ~0, 1, RF_ACTIVE);
@@ -296,16 +293,16 @@ mss_alloc_resources(struct mss_info *mss, device_t dev)
     	if (mss->drq2_rid >= 0 && !mss->drq2) ok = 0;
 
 	if (ok) {
-		mss->pdma = rman_get_start(mss->drq1);
-		isa_dma_acquire(mss->pdma);
-		isa_dmainit(mss->pdma, MSS_BUFFSIZE);
+		pdma = rman_get_start(mss->drq1);
+		isa_dma_acquire(pdma);
+		isa_dmainit(pdma, MSS_BUFFSIZE);
 		mss->bd_flags &= ~BD_F_DUPLEX;
 		if (mss->drq2) {
-			mss->rdma = rman_get_start(mss->drq2);
-			isa_dma_acquire(mss->rdma);
-			isa_dmainit(mss->rdma, MSS_BUFFSIZE);
+			rdma = rman_get_start(mss->drq2);
+			isa_dma_acquire(rdma);
+			isa_dmainit(rdma, MSS_BUFFSIZE);
 			mss->bd_flags |= BD_F_DUPLEX;
-		} else mss->rdma = mss->pdma;
+		} else mss->drq2 = mss->drq1;
 	}
     	return ok;
 }
@@ -691,11 +688,11 @@ mss_intr(void *arg)
 		/* get exact reason for full-duplex boards */
 		c = FULL_DUPLEX(mss)? ad_read(mss, 24) : 0x30;
 		c &= ~served;
-		if (mss->pch.buffer->dl && (c & 0x10)) {
+		if (sndbuf_runsz(mss->pch.buffer) && (c & 0x10)) {
 	    		served |= 0x10;
 	    		chn_intr(mss->pch.channel);
 		}
-		if (mss->rch.buffer->dl && (c & 0x20)) {
+		if (sndbuf_runsz(mss->rch.buffer) && (c & 0x20)) {
 	    		served |= 0x20;
 	    		chn_intr(mss->rch.channel);
 		}
@@ -935,7 +932,7 @@ mss_trigger(struct mss_chinfo *ch, int go)
     	m = ad_read(mss, 9);
     	switch (go) {
     	case PCMTRIG_START:
-		cnt = (ch->buffer->dl / ss) - 1;
+		cnt = (ch->blksz / ss) - 1;
 
 		DEB(if (m & 4) printf("OUCH! reg 9 0x%02x\n", m););
 		m |= wr? I9_PEN : I9_CEN; /* enable DMA */
@@ -1015,8 +1012,8 @@ opti931_intr(void *arg)
 		return;
     	}
 
-    	if (mss->rch.buffer->dl && (mc11 & 8)) chn_intr(mss->rch.channel);
-    	if (mss->pch.buffer->dl && (mc11 & 4)) chn_intr(mss->pch.channel);
+    	if (sndbuf_runsz(mss->rch.buffer) && (mc11 & 8)) chn_intr(mss->rch.channel);
+    	if (sndbuf_runsz(mss->pch.buffer) && (mc11 & 4)) chn_intr(mss->pch.channel);
     	opti_wr(mss, 11, ~mc11); /* ack */
     	if (--loops) goto again;
     	DEB(printf("xxx too many loops\n");)
@@ -1033,10 +1030,9 @@ msschan_init(kobj_t obj, void *devinfo, snd_dbuf *b, pcm_channel *c, int dir)
 	ch->parent = mss;
 	ch->channel = c;
 	ch->buffer = b;
-	ch->buffer->bufsize = MSS_BUFFSIZE;
-	ch->buffer->chan = (dir == PCMDIR_PLAY)? mss->pdma : mss->rdma;
 	ch->dir = dir;
-	if (chn_allocbuf(ch->buffer, mss->parent_dmat) == -1) return NULL;
+	if (sndbuf_alloc(ch->buffer, mss->parent_dmat, MSS_BUFFSIZE) == -1) return NULL;
+	sndbuf_isadmasetup(ch->buffer, (dir == PCMDIR_PLAY)? mss->drq1 : mss->drq2);
 	return ch;
 }
 
@@ -1060,7 +1056,10 @@ msschan_setspeed(kobj_t obj, void *data, u_int32_t speed)
 static int
 msschan_setblocksize(kobj_t obj, void *data, u_int32_t blocksize)
 {
-	return blocksize;
+	struct mss_chinfo *ch = data;
+
+	ch->blksz = blocksize;
+	return ch->blksz;
 }
 
 static int
@@ -1071,7 +1070,7 @@ msschan_trigger(kobj_t obj, void *data, int go)
 	if (go == PCMTRIG_EMLDMAWR || go == PCMTRIG_EMLDMARD)
 		return 0;
 
-	buf_isadma(ch->buffer, go);
+	sndbuf_isadma(ch->buffer, go);
 	mss_trigger(ch, go);
 	return 0;
 }
@@ -1080,7 +1079,7 @@ static int
 msschan_getptr(kobj_t obj, void *data)
 {
 	struct mss_chinfo *ch = data;
-	return buf_isadmaptr(ch->buffer);
+	return sndbuf_isadmaptr(ch->buffer);
 }
 
 static pcmchan_caps *
@@ -1496,11 +1495,13 @@ ymf_test(device_t dev, struct mss_info *mss)
 static int
 mss_doattach(device_t dev, struct mss_info *mss)
 {
-    	int flags = device_get_flags(dev);
+    	int pdma, rdma, flags = device_get_flags(dev);
     	char status[SND_STATUSLEN];
 
     	if (!mss_alloc_resources(mss, dev)) goto no;
     	mss_init(mss, dev);
+	pdma = rman_get_start(mss->drq1);
+	rdma = rman_get_start(mss->drq2);
     	if (flags & DV_F_TRUE_MSS) {
 		/* has IRQ/DMA registers, set IRQ and DMA addr */
 #ifdef PC98 /* CS423[12] in PC98 can use IRQ3,5,10,12 */
@@ -1521,13 +1522,12 @@ mss_doattach(device_t dev, struct mss_info *mss)
 		if ((io_rd(mss, 3) & 0x40) == 0) device_printf(dev, "IRQ Conflict?\n");
 #endif
 		/* Write IRQ+DMA setup */
-		if (pdma_bits[mss->pdma] == -1) goto no;
-		bits |= pdma_bits[mss->pdma];
-		if (mss->pdma != mss->rdma) {
-	    		if (mss->rdma == valid_rdma[mss->pdma]) bits |= 4;
+		if (pdma_bits[pdma] == -1) goto no;
+		bits |= pdma_bits[pdma];
+		if (pdma != rdma) {
+	    		if (rdma == valid_rdma[pdma]) bits |= 4;
 	    		else {
-				printf("invalid dual dma config %d:%d\n",
-			       	mss->pdma, mss->rdma);
+				printf("invalid dual dma config %d:%d\n", pdma, rdma);
 				goto no;
 	    		}
 		}
@@ -1542,7 +1542,7 @@ mss_doattach(device_t dev, struct mss_info *mss)
     	default:
 		bus_setup_intr(dev, mss->irq, INTR_TYPE_TTY, mss_intr, mss, &mss->ih);
     	}
-    	if (mss->pdma == mss->rdma)
+    	if (pdma == rdma)
 		pcm_setflags(dev, pcm_getflags(dev) | SD_F_SIMPLEX);
     	if (bus_dma_tag_create(/*parent*/NULL, /*alignment*/2, /*boundary*/0,
 			/*lowaddr*/BUS_SPACE_MAXADDR_24BIT,
@@ -1555,9 +1555,9 @@ mss_doattach(device_t dev, struct mss_info *mss)
 		goto no;
     	}
     	snprintf(status, SND_STATUSLEN, "at io 0x%lx irq %ld drq %d",
-    	     	rman_get_start(mss->io_base), rman_get_start(mss->irq), mss->pdma);
-    	if (mss->pdma != mss->rdma) snprintf(status + strlen(status),
-        	SND_STATUSLEN - strlen(status), ":%d", mss->rdma);
+    	     	rman_get_start(mss->io_base), rman_get_start(mss->irq), pdma);
+    	if (pdma != rdma) snprintf(status + strlen(status),
+        	SND_STATUSLEN - strlen(status), ":%d", rdma);
 
     	if (pcm_register(dev, mss, 1, 1)) goto no;
     	pcm_addchan(dev, PCMDIR_REC, &msschan_class, mss);
diff --git a/sys/dev/sound/isa/sb16.c b/sys/dev/sound/isa/sb16.c
index e1485fa..ce69b54 100644
--- a/sys/dev/sound/isa/sb16.c
+++ b/sys/dev/sound/isa/sb16.c
@@ -84,7 +84,7 @@ struct sb_info {
 
     	int bd_id;
     	u_long bd_flags;       /* board-specific flags */
-	int dl, dh, prio, prio16;
+	int prio, prio16;
     	struct sb_chinfo pch, rch;
 };
 
@@ -370,15 +370,15 @@ sb16_release_resources(struct sb_info *sb, device_t dev)
  		bus_release_resource(dev, SYS_RES_IRQ, 0, sb->irq);
 		sb->irq = 0;
     	}
-    	if (sb->drq1) {
-		bus_release_resource(dev, SYS_RES_DRQ, 0, sb->drq1);
-		sb->drq1 = 0;
-    	}
-    	if (sb->drq2) {
+    	if (sb->drq2 && (sb->drq2 != sb->drq2)) {
 		bus_release_resource(dev, SYS_RES_DRQ, 1, sb->drq2);
 		sb->drq2 = 0;
     	}
-    	if (sb->io_base) {
+     	if (sb->drq1) {
+		bus_release_resource(dev, SYS_RES_DRQ, 0, sb->drq1);
+		sb->drq1 = 0;
+    	}
+   	if (sb->io_base) {
 		bus_release_resource(dev, SYS_RES_IOPORT, 0, sb->io_base);
 		sb->io_base = 0;
     	}
@@ -419,6 +419,9 @@ sb16_alloc_resources(struct sb_info *sb, device_t dev)
 		if (sb->drq2) {
 			isa_dma_acquire(rman_get_start(sb->drq2));
 			isa_dmainit(rman_get_start(sb->drq2), bs);
+		} else {
+			sb->drq2 = sb->drq1;
+			pcm_setflags(dev, pcm_getflags(dev) | SD_F_SIMPLEX);
 		}
 		return 0;
 	} else return ENXIO;
@@ -458,15 +461,15 @@ sb_intr(void *arg)
     		}
 	} else {
     		if (c & 1) { /* 8-bit dma */
-			if (sb->pch.dch == sb->dl)
+			if (sb->pch.dch == 1)
 				reason |= 1;
-			if (sb->rch.dch == sb->dl)
+			if (sb->rch.dch == 1)
 				reason |= 2;
     		}
     		if (c & 2) { /* 16-bit dma */
-			if (sb->pch.dch == sb->dh)
+			if (sb->pch.dch == 2)
 				reason |= 1;
-			if (sb->rch.dch == sb->dh)
+			if (sb->rch.dch == 2)
 				reason |= 2;
     		}
 	}
@@ -494,38 +497,43 @@ sb_setup(struct sb_info *sb)
 	int l, pprio;
 
 	if (sb->bd_flags & BD_F_DMARUN)
-		buf_isadma(sb->pch.buffer, PCMTRIG_STOP);
+		sndbuf_isadma(sb->pch.buffer, PCMTRIG_STOP);
 	if (sb->bd_flags & BD_F_DMARUN2)
-		buf_isadma(sb->rch.buffer, PCMTRIG_STOP);
+		sndbuf_isadma(sb->rch.buffer, PCMTRIG_STOP);
 	sb->bd_flags &= ~(BD_F_DMARUN | BD_F_DMARUN2);
 
 	sb_reset_dsp(sb);
 
 	if (sb->bd_flags & BD_F_SB16X) {
 		pprio = sb->pch.run? 1 : 0;
-		sb->pch.buffer->chan = pprio? sb->dl : -1;
-		sb->rch.buffer->chan = pprio? sb->dh : sb->dl;
+		sndbuf_isadmasetup(sb->pch.buffer, pprio? sb->drq1 : NULL);
+		sb->pch.dch = pprio? 1 : 0;
+		sndbuf_isadmasetup(sb->rch.buffer, pprio? sb->drq2 : sb->drq1);
+		sb->rch.dch = pprio? 2 : 1;
 	} else {
 		if (sb->pch.run && sb->rch.run) {
 			pprio = (sb->rch.fmt & AFMT_16BIT)? 0 : 1;
-			sb->pch.buffer->chan = pprio? sb->dh : sb->dl;
-			sb->rch.buffer->chan = pprio? sb->dl : sb->dh;
+			sndbuf_isadmasetup(sb->pch.buffer, pprio? sb->drq2 : sb->drq1);
+			sb->pch.dch = pprio? 2 : 1;
+			sndbuf_isadmasetup(sb->rch.buffer, pprio? sb->drq1 : sb->drq2);
+			sb->rch.dch = pprio? 1 : 2;
 		} else {
 			if (sb->pch.run) {
-				sb->pch.buffer->chan = (sb->pch.fmt & AFMT_16BIT)? sb->dh : sb->dl;
-				sb->rch.buffer->chan = (sb->pch.fmt & AFMT_16BIT)? sb->dl : sb->dh;
+				sndbuf_isadmasetup(sb->pch.buffer, (sb->pch.fmt & AFMT_16BIT)? sb->drq2 : sb->drq1);
+				sb->pch.dch = (sb->pch.fmt & AFMT_16BIT)? 2 : 1;
+				sndbuf_isadmasetup(sb->rch.buffer, (sb->pch.fmt & AFMT_16BIT)? sb->drq1 : sb->drq2);
+				sb->rch.dch = (sb->pch.fmt & AFMT_16BIT)? 1 : 2;
 			} else if (sb->rch.run) {
-				sb->pch.buffer->chan = (sb->rch.fmt & AFMT_16BIT)? sb->dl : sb->dh;
-				sb->rch.buffer->chan = (sb->rch.fmt & AFMT_16BIT)? sb->dh : sb->dl;
+				sndbuf_isadmasetup(sb->pch.buffer, (sb->rch.fmt & AFMT_16BIT)? sb->drq1 : sb->drq2);
+				sb->pch.dch = (sb->rch.fmt & AFMT_16BIT)? 1 : 2;
+				sndbuf_isadmasetup(sb->rch.buffer, (sb->rch.fmt & AFMT_16BIT)? sb->drq2 : sb->drq1);
+				sb->rch.dch = (sb->rch.fmt & AFMT_16BIT)? 2 : 1;
 			}
 		}
 	}
 
-	sb->pch.dch = sb->pch.buffer->chan;
-	sb->rch.dch = sb->rch.buffer->chan;
-
-	sb->pch.buffer->dir = ISADMA_WRITE;
-	sb->rch.buffer->dir = ISADMA_READ;
+	sndbuf_isadmasetdir(sb->pch.buffer, PCMDIR_PLAY);
+	sndbuf_isadmasetdir(sb->rch.buffer, PCMDIR_REC);
 
 	/*
 	printf("setup: [pch = %d, pfmt = %d, pgo = %d] [rch = %d, rfmt = %d, rgo = %d]\n",
@@ -553,7 +561,7 @@ sb_setup(struct sb_info *sb)
 		v = (ch->fmt & AFMT_STEREO)? DSP_F16_STEREO : 0;
 		v |= (ch->fmt & AFMT_SIGNED)? DSP_F16_SIGNED : 0;
 		sb_cmd2(sb, v, l);
-		buf_isadma(ch->buffer, PCMTRIG_START);
+		sndbuf_isadma(ch->buffer, PCMTRIG_START);
 		sb->bd_flags |= BD_F_DMARUN;
 	}
 
@@ -578,7 +586,7 @@ sb_setup(struct sb_info *sb)
 		v = (ch->fmt & AFMT_STEREO)? DSP_F16_STEREO : 0;
 		v |= (ch->fmt & AFMT_SIGNED)? DSP_F16_SIGNED : 0;
 		sb_cmd2(sb, v, l);
-		buf_isadma(ch->buffer, PCMTRIG_START);
+		sndbuf_isadma(ch->buffer, PCMTRIG_START);
 		sb->bd_flags |= BD_F_DMARUN2;
 	}
 
@@ -595,10 +603,9 @@ sb16chan_init(kobj_t obj, void *devinfo, snd_dbuf *b, pcm_channel *c, int dir)
 	ch->parent = sb;
 	ch->channel = c;
 	ch->buffer = b;
-	ch->buffer->bufsize = SB16_BUFFSIZE;
 	ch->dir = dir;
 
-	if (chn_allocbuf(ch->buffer, sb->parent_dmat) == -1)
+	if (sndbuf_alloc(ch->buffer, sb->parent_dmat, SB16_BUFFSIZE) == -1)
 		return NULL;
 
 	return ch;
@@ -632,7 +639,7 @@ sb16chan_setblocksize(kobj_t obj, void *data, u_int32_t blocksize)
 	struct sb_chinfo *ch = data;
 
 	ch->blksz = blocksize;
-	return blocksize;
+	return ch->blksz;
 }
 
 static int
@@ -659,7 +666,7 @@ sb16chan_getptr(kobj_t obj, void *data)
 {
 	struct sb_chinfo *ch = data;
 
-	return buf_isadmaptr(ch->buffer);
+	return sndbuf_isadmaptr(ch->buffer);
 }
 
 static pcmchan_caps *
@@ -749,11 +756,9 @@ sb16_attach(device_t dev)
 	if (bus_setup_intr(dev, sb->irq, INTR_TYPE_TTY, sb_intr, sb, &sb->ih))
 		goto no;
 
-	if (!sb->drq2 || (sb->bd_flags & BD_F_SB16X))
+	if (sb->bd_flags & BD_F_SB16X)
 		pcm_setflags(dev, pcm_getflags(dev) | SD_F_SIMPLEX);
 
-	sb->dl = rman_get_start(sb->drq1);
-	sb->dh = sb->drq2? rman_get_start(sb->drq2) : sb->dl;
 	sb->prio = 0;
 
     	if (bus_dma_tag_create(/*parent*/NULL, /*alignment*/2, /*boundary*/0,
@@ -770,7 +775,7 @@ sb16_attach(device_t dev)
     	snprintf(status, SND_STATUSLEN, "at io 0x%lx irq %ld drq %ld",
     	     	rman_get_start(sb->io_base), rman_get_start(sb->irq),
 		rman_get_start(sb->drq1));
-    	if (sb->drq2)
+    	if (!(pcm_getflags(dev) & SD_F_SIMPLEX))
 		snprintf(status + strlen(status), SND_STATUSLEN - strlen(status),
 			":%ld", rman_get_start(sb->drq2));
 
diff --git a/sys/dev/sound/isa/sb8.c b/sys/dev/sound/isa/sb8.c
index b2e66b3..39a8f95 100644
--- a/sys/dev/sound/isa/sb8.c
+++ b/sys/dev/sound/isa/sb8.c
@@ -64,7 +64,7 @@ struct sb_chinfo {
 	pcm_channel *channel;
 	snd_dbuf *buffer;
 	int dir;
-	u_int32_t fmt, spd;
+	u_int32_t fmt, spd, blksz;
 };
 
 struct sb_info {
@@ -463,10 +463,10 @@ sb_intr(void *arg)
 {
     	struct sb_info *sb = (struct sb_info *)arg;
 
-    	if (sb->pch.buffer->dl > 0)
+    	if (sndbuf_runsz(sb->pch.buffer) > 0)
 		chn_intr(sb->pch.channel);
 
-    	if (sb->rch.buffer->dl > 0)
+    	if (sndbuf_runsz(sb->rch.buffer) > 0)
 		chn_intr(sb->rch.channel);
 
 	sb_rd(sb, DSP_DATA_AVAIL); /* int ack */
@@ -517,7 +517,7 @@ sb_start(struct sb_chinfo *ch)
 	struct sb_info *sb = ch->parent;
     	int play = (ch->dir == PCMDIR_PLAY)? 1 : 0;
     	int stereo = (ch->fmt & AFMT_STEREO)? 1 : 0;
-	int l = ch->buffer->dl;
+	int l = ch->blksz;
 	u_char i;
 
 	l--;
@@ -566,10 +566,9 @@ sbchan_init(kobj_t obj, void *devinfo, snd_dbuf *b, pcm_channel *c, int dir)
 	ch->channel = c;
 	ch->dir = dir;
 	ch->buffer = b;
-	ch->buffer->bufsize = SB_BUFFSIZE;
-	ch->buffer->chan = rman_get_start(sb->drq);
-	if (chn_allocbuf(ch->buffer, sb->parent_dmat) == -1)
+	if (sndbuf_alloc(ch->buffer, sb->parent_dmat, SB_BUFFSIZE) == -1)
 		return NULL;
+	sndbuf_isadmasetup(ch->buffer, sb->drq);
 	return ch;
 }
 
@@ -594,7 +593,10 @@ sbchan_setspeed(kobj_t obj, void *data, u_int32_t speed)
 static int
 sbchan_setblocksize(kobj_t obj, void *data, u_int32_t blocksize)
 {
-	return blocksize;
+	struct sb_chinfo *ch = data;
+
+	ch->blksz = blocksize;
+	return ch->blksz;
 }
 
 static int
@@ -605,7 +607,7 @@ sbchan_trigger(kobj_t obj, void *data, int go)
 	if (go == PCMTRIG_EMLDMAWR || go == PCMTRIG_EMLDMARD)
 		return 0;
 
-	buf_isadma(ch->buffer, go);
+	sndbuf_isadma(ch->buffer, go);
 	if (go == PCMTRIG_START)
 		sb_start(ch);
 	else
@@ -618,7 +620,7 @@ sbchan_getptr(kobj_t obj, void *data)
 {
 	struct sb_chinfo *ch = data;
 
-	return buf_isadmaptr(ch->buffer);
+	return sndbuf_isadmaptr(ch->buffer);
 }
 
 static pcmchan_caps *
diff --git a/sys/dev/sound/pci/aureal.c b/sys/dev/sound/pci/aureal.c
index e957b07..09ead9f 100644
--- a/sys/dev/sound/pci/aureal.c
+++ b/sys/dev/sound/pci/aureal.c
@@ -242,7 +242,7 @@ au_prepareoutput(struct au_chinfo *ch, u_int32_t format)
 {
 	struct au_info *au = ch->parent;
 	int i, stereo = (format & AFMT_STEREO)? 1 : 0;
-	u_int32_t baseaddr = vtophys(ch->buffer->buf);
+	u_int32_t baseaddr = vtophys(sndbuf_getbuf(ch->buffer));
 
 	au_wr(au, 0, 0x1061c, 0, 4);
 	au_wr(au, 0, 0x10620, 0, 4);
@@ -301,9 +301,8 @@ auchan_init(kobj_t obj, void *devinfo, snd_dbuf *b, pcm_channel *c, int dir)
 	ch->parent = au;
 	ch->channel = c;
 	ch->buffer = b;
-	ch->buffer->bufsize = AU_BUFFSIZE;
 	ch->dir = dir;
-	if (chn_allocbuf(ch->buffer, au->parent_dmat) == -1) return NULL;
+	if (sndbuf_alloc(ch->buffer, au->parent_dmat, AU_BUFFSIZE) == -1) return NULL;
 	return ch;
 }
 
diff --git a/sys/dev/sound/pci/csapcm.c b/sys/dev/sound/pci/csapcm.c
index c3ae93e..8bad7b5 100644
--- a/sys/dev/sound/pci/csapcm.c
+++ b/sys/dev/sound/pci/csapcm.c
@@ -523,8 +523,7 @@ csachan_init(kobj_t obj, void *devinfo, snd_dbuf *b, pcm_channel *c, int dir)
 	ch->parent = csa;
 	ch->channel = c;
 	ch->buffer = b;
-	ch->buffer->bufsize = CS461x_BUFFSIZE;
-	if (chn_allocbuf(ch->buffer, csa->parent_dmat) == -1) return NULL;
+	if (sndbuf_alloc(ch->buffer, csa->parent_dmat, CS461x_BUFFSIZE) == -1) return NULL;
 	return ch;
 }
 
@@ -538,9 +537,9 @@ csachan_setdir(kobj_t obj, void *data, int dir)
 	resp = &csa->res;
 
 	if (dir == PCMDIR_PLAY)
-		csa_writemem(resp, BA1_PBA, vtophys(ch->buffer->buf));
+		csa_writemem(resp, BA1_PBA, vtophys(sndbuf_getbuf(ch->buffer)));
 	else
-		csa_writemem(resp, BA1_CBA, vtophys(ch->buffer->buf));
+		csa_writemem(resp, BA1_CBA, vtophys(sndbuf_getbuf(ch->buffer)));
 	ch->dir = dir;
 	return 0;
 }
@@ -606,12 +605,7 @@ csachan_setspeed(kobj_t obj, void *data, u_int32_t speed)
 static int
 csachan_setblocksize(kobj_t obj, void *data, u_int32_t blocksize)
 {
-#if notdef
-	return blocksize;
-#else
-	struct csa_chinfo *ch = data;
-	return ch->buffer->bufsize / 2;
-#endif /* notdef */
+	return CS461x_BUFFSIZE / 2;
 }
 
 static int
@@ -648,11 +642,11 @@ csachan_getptr(kobj_t obj, void *data)
 	resp = &csa->res;
 
 	if (ch->dir == PCMDIR_PLAY) {
-		ptr = csa_readmem(resp, BA1_PBA) - vtophys(ch->buffer->buf);
+		ptr = csa_readmem(resp, BA1_PBA) - vtophys(sndbuf_getbuf(ch->buffer));
 		if ((ch->fmt & AFMT_U8) != 0 || (ch->fmt & AFMT_S8) != 0)
 			ptr >>= 1;
 	} else {
-		ptr = csa_readmem(resp, BA1_CBA) - vtophys(ch->buffer->buf);
+		ptr = csa_readmem(resp, BA1_CBA) - vtophys(sndbuf_getbuf(ch->buffer));
 		if ((ch->fmt & AFMT_U8) != 0 || (ch->fmt & AFMT_S8) != 0)
 			ptr >>= 1;
 	}
diff --git a/sys/dev/sound/pci/ds1.c b/sys/dev/sound/pci/ds1.c
index c215b5a..5d76502 100644
--- a/sys/dev/sound/pci/ds1.c
+++ b/sys/dev/sound/pci/ds1.c
@@ -431,8 +431,8 @@ ds_setuppch(struct sc_pchinfo *ch)
 	stereo = (ch->fmt & AFMT_STEREO)? 1 : 0;
 	b16 = (ch->fmt & AFMT_16BIT)? 1 : 0;
 	c = stereo? 1 : 0;
-	buf = ch->buffer->buf;
-	sz = ch->buffer->bufsize;
+	buf = sndbuf_getbuf(ch->buffer);
+	sz = sndbuf_getsize(ch->buffer);
 
 	ds_initpbank(ch->lslot, c, stereo, b16, ch->spd, buf, sz);
 	ds_initpbank(ch->lslot + 1, c, stereo, b16, ch->spd, buf, sz);
@@ -450,8 +450,8 @@ ds_setuprch(struct sc_rchinfo *ch)
 
 	stereo = (ch->fmt & AFMT_STEREO)? 1 : 0;
 	b16 = (ch->fmt & AFMT_16BIT)? 1 : 0;
-	buf = ch->buffer->buf;
-	sz = ch->buffer->bufsize;
+	buf = sndbuf_getbuf(ch->buffer);
+	sz = sndbuf_getsize(ch->buffer);
 	pri = (ch->num == DS1_RECPRIMARY)? 1 : 0;
 
 	for (i = 0; i < 2; i++) {
@@ -480,14 +480,13 @@ ds1pchan_init(kobj_t obj, void *devinfo, snd_dbuf *b, pcm_channel *c, int dir)
 
 	ch = &sc->pch[sc->pchn++];
 	ch->buffer = b;
-	ch->buffer->bufsize = 4096;
 	ch->parent = sc;
 	ch->channel = c;
 	ch->dir = dir;
 	ch->fmt = AFMT_U8;
 	ch->spd = 8000;
 	ch->run = 0;
-	if (chn_allocbuf(ch->buffer, sc->parent_dmat) == -1)
+	if (sndbuf_alloc(ch->buffer, sc->parent_dmat, 4096) == -1)
 		return NULL;
 	else {
 		ch->lsnum = sc->pslotfree;
@@ -602,13 +601,12 @@ ds1rchan_init(kobj_t obj, void *devinfo, snd_dbuf *b, pcm_channel *c, int dir)
 	ch = &sc->rch[sc->rchn];
 	ch->num = sc->rchn++;
 	ch->buffer = b;
-	ch->buffer->bufsize = 4096;
 	ch->parent = sc;
 	ch->channel = c;
 	ch->dir = dir;
 	ch->fmt = AFMT_U8;
 	ch->spd = 8000;
-	if (chn_allocbuf(ch->buffer, sc->parent_dmat) == -1)
+	if (sndbuf_alloc(ch->buffer, sc->parent_dmat, 4096) == -1)
 		return NULL;
 	else {
 		ch->slot = (ch->num == DS1_RECPRIMARY)? sc->rbank + 2: sc->rbank;
diff --git a/sys/dev/sound/pci/emu10k1.c b/sys/dev/sound/pci/emu10k1.c
index e199446..e816572 100644
--- a/sys/dev/sound/pci/emu10k1.c
+++ b/sys/dev/sound/pci/emu10k1.c
@@ -68,7 +68,7 @@ struct sc_info;
 
 /* channel registers */
 struct sc_pchinfo {
-	int spd, fmt, run;
+	int spd, fmt, blksz, run;
 	struct emu_voice *master, *slave;
 	snd_dbuf *buffer;
 	pcm_channel *channel;
@@ -76,7 +76,7 @@ struct sc_pchinfo {
 };
 
 struct sc_rchinfo {
-	int spd, fmt, run, num;
+	int spd, fmt, run, blksz, num;
 	u_int32_t idxreg, basereg, sizereg, setupreg, irqmask;
 	snd_dbuf *buffer;
 	pcm_channel *channel;
@@ -97,7 +97,7 @@ struct sc_info {
 	int		regtype, regid, irqid;
 	void		*ih;
 
-	int timer;
+	int timer, timerinterval;
 	int pnum, rnum;
 	struct emu_mem mem;
 	struct emu_voice voice[64];
@@ -303,12 +303,39 @@ emu_enaint(struct sc_info *sc, char channel, int enable)
 
 /* stuff */
 static int
+emu_settimer(struct sc_info *sc)
+{
+	struct sc_pchinfo *pch;
+	struct sc_rchinfo *rch;
+	int i, tmp, rate;
+
+	rate = 0;
+	for (i = 0; i < EMU_CHANS; i++) {
+		pch = &sc->pch[i];
+		tmp = (pch->spd * sndbuf_getbps(pch->buffer)) / pch->blksz;
+		if (tmp > rate)
+			rate = tmp;
+	}
+
+	for (i = 0; i < 3; i++) {
+		rch = &sc->rch[i];
+		tmp = (rch->spd * sndbuf_getbps(rch->buffer)) / rch->blksz;
+		if (tmp > rate)
+			rate = tmp;
+	}
+	RANGE(rate, 48, 9600);
+	sc->timerinterval = 48000 / rate;
+	emu_wr(sc, TIMER, sc->timerinterval & 0x03ff, 2);
+
+	return sc->timerinterval;
+}
+
+static int
 emu_enatimer(struct sc_info *sc, int go)
 {
 	u_int32_t x;
 	if (go) {
 		if (sc->timer++ == 0) {
-			emu_wr(sc, TIMER, 256, 2);
 			x = emu_rd(sc, INTE, 4);
 			x |= INTE_INTERVALTIMERENB;
 			emu_wr(sc, INTE, x, 4);
@@ -430,10 +457,8 @@ emu_vinit(struct sc_info *sc, struct emu_voice *m, struct emu_voice *s,
 	buf = emu_memalloc(sc, sz);
 	if (buf == NULL)
 		return -1;
-	if (c != NULL) {
-		c->buffer.buf = buf;
-		c->buffer.bufsize = sz;
-	}
+	if (c != NULL)
+		sndbuf_setup(&c->buffer, buf, sz);
 	m->start = emu_memstart(sc, buf) * EMUPAGESIZE;
 	m->end = m->start + sz;
 	m->channel = NULL;
@@ -631,6 +656,9 @@ emupchan_init(kobj_t obj, void *devinfo, snd_dbuf *b, pcm_channel *c, int dir)
 	ch->buffer = b;
 	ch->parent = sc;
 	ch->channel = c;
+	ch->blksz = EMU_BUFFSIZE / 2;
+	ch->fmt = AFMT_U8;
+	ch->spd = 8000;
 	ch->master = emu_valloc(sc);
 	ch->slave = emu_valloc(sc);
 	if (emu_vinit(sc, ch->master, ch->slave, EMU_BUFFSIZE, ch->channel))
@@ -645,7 +673,7 @@ emupchan_free(kobj_t obj, void *data)
 	struct sc_pchinfo *ch = data;
 	struct sc_info *sc = ch->parent;
 
-	return emu_memfree(sc, ch->buffer->buf);
+	return emu_memfree(sc, sndbuf_getbuf(ch->buffer));
 }
 
 static int
@@ -669,6 +697,14 @@ emupchan_setspeed(kobj_t obj, void *data, u_int32_t speed)
 static int
 emupchan_setblocksize(kobj_t obj, void *data, u_int32_t blocksize)
 {
+	struct sc_pchinfo *ch = data;
+	struct sc_info *sc = ch->parent;
+	int irqrate, blksz;
+
+	ch->blksz = blocksize;
+	emu_settimer(sc);
+	irqrate = 48000 / sc->timerinterval;
+	blksz = (ch->spd * sndbuf_getbps(ch->buffer)) / irqrate;
 	return blocksize;
 }
 
@@ -684,6 +720,7 @@ emupchan_trigger(kobj_t obj, void *data, int go)
 	if (go == PCMTRIG_START) {
 		emu_vsetup(ch);
 		emu_vwrite(sc, ch->master);
+		emu_settimer(sc);
 		emu_enatimer(sc, 1);
 #ifdef EMUDEBUG
 		printf("start [%d bit, %s, %d hz]\n",
@@ -737,9 +774,9 @@ emurchan_init(kobj_t obj, void *devinfo, snd_dbuf *b, pcm_channel *c, int dir)
 	KASSERT(dir == PCMDIR_REC, ("emurchan_init: bad direction"));
 	ch = &sc->rch[sc->rnum];
 	ch->buffer = b;
-	ch->buffer->bufsize = EMU_BUFFSIZE;
 	ch->parent = sc;
 	ch->channel = c;
+	ch->blksz = EMU_BUFFSIZE / 2;
 	ch->fmt = AFMT_U8;
 	ch->spd = 8000;
 	ch->num = sc->rnum;
@@ -769,10 +806,10 @@ emurchan_init(kobj_t obj, void *devinfo, snd_dbuf *b, pcm_channel *c, int dir)
 		break;
 	}
 	sc->rnum++;
-	if (chn_allocbuf(ch->buffer, sc->parent_dmat) == -1)
+	if (sndbuf_alloc(ch->buffer, sc->parent_dmat, EMU_BUFFSIZE) == -1)
 		return NULL;
 	else {
-		emu_wrptr(sc, 0, ch->basereg, vtophys(ch->buffer->buf));
+		emu_wrptr(sc, 0, ch->basereg, vtophys(sndbuf_getbuf(ch->buffer)));
 		emu_wrptr(sc, 0, ch->sizereg, 0); /* off */
 		return ch;
 	}
@@ -805,6 +842,14 @@ emurchan_setspeed(kobj_t obj, void *data, u_int32_t speed)
 static int
 emurchan_setblocksize(kobj_t obj, void *data, u_int32_t blocksize)
 {
+	struct sc_rchinfo *ch = data;
+	struct sc_info *sc = ch->parent;
+	int irqrate, blksz;
+
+	ch->blksz = blocksize;
+	emu_settimer(sc);
+	irqrate = 48000 / sc->timerinterval;
+	blksz = (ch->spd * sndbuf_getbps(ch->buffer)) / irqrate;
 	return blocksize;
 }
 
diff --git a/sys/dev/sound/pci/es137x.c b/sys/dev/sound/pci/es137x.c
index 15779e8..0206dce 100644
--- a/sys/dev/sound/pci/es137x.c
+++ b/sys/dev/sound/pci/es137x.c
@@ -253,9 +253,8 @@ eschan_init(kobj_t obj, void *devinfo, snd_dbuf *b, pcm_channel *c, int dir)
 	ch->parent = es;
 	ch->channel = c;
 	ch->buffer = b;
-	ch->buffer->bufsize = ES_BUFFSIZE;
 	ch->num = ch->parent->num++;
-	if (chn_allocbuf(ch->buffer, es->parent_dmat) == -1) return NULL;
+	if (sndbuf_alloc(ch->buffer, es->parent_dmat, ES_BUFFSIZE) == -1) return NULL;
 	return ch;
 }
 
@@ -269,16 +268,16 @@ eschan_setdir(kobj_t obj, void *data, int dir)
 		bus_space_write_1(es->st, es->sh, ES1370_REG_MEMPAGE,
 				  ES1370_REG_DAC2_FRAMEADR >> 8);
 		bus_space_write_4(es->st, es->sh, ES1370_REG_DAC2_FRAMEADR & 0xff,
-				  vtophys(ch->buffer->buf));
+				  vtophys(sndbuf_getbuf(ch->buffer)));
 		bus_space_write_4(es->st, es->sh, ES1370_REG_DAC2_FRAMECNT & 0xff,
-				  (ch->buffer->bufsize >> 2) - 1);
+				  (sndbuf_getsize(ch->buffer) >> 2) - 1);
 	} else {
 		bus_space_write_1(es->st, es->sh, ES1370_REG_MEMPAGE,
 				  ES1370_REG_ADC_FRAMEADR >> 8);
 		bus_space_write_4(es->st, es->sh, ES1370_REG_ADC_FRAMEADR & 0xff,
-				  vtophys(ch->buffer->buf));
+				  vtophys(sndbuf_getbuf(ch->buffer)));
 		bus_space_write_4(es->st, es->sh, ES1370_REG_ADC_FRAMECNT & 0xff,
-				  (ch->buffer->bufsize >> 2) - 1);
+				  (sndbuf_getsize(ch->buffer) >> 2) - 1);
 	}
 	ch->dir = dir;
 	return 0;
@@ -346,10 +345,7 @@ eschan_trigger(kobj_t obj, void *data, int go)
 	if (go == PCMTRIG_EMLDMAWR || go == PCMTRIG_EMLDMARD)
 		return 0;
 
-	ss = 1;
-	ss <<= (ch->fmt & AFMT_STEREO)? 1 : 0;
-	ss <<= (ch->fmt & AFMT_16BIT)? 1 : 0;
-	cnt = ch->buffer->dl / ss - 1;
+	cnt = (sndbuf_runsz(ch->buffer) / sndbuf_getbps(ch->buffer)) - 1;
 
 	if (ch->dir == PCMDIR_PLAY) {
 		if (go == PCMTRIG_START) {
@@ -366,7 +362,7 @@ eschan_trigger(kobj_t obj, void *data, int go)
 					  ES1370_REG_DAC2_FRAMECNT >> 8);
 			bus_space_write_4(es->st, es->sh,
 					  ES1370_REG_DAC2_FRAMECNT & 0xff,
-				  	  (ch->buffer->bufsize >> 2) - 1);
+				  	  (sndbuf_getsize(ch->buffer) >> 2) - 1);
 		} else es->ctrl &= ~CTRL_DAC2_EN;
 	} else {
 		if (go == PCMTRIG_START) {
@@ -380,7 +376,7 @@ eschan_trigger(kobj_t obj, void *data, int go)
 					  ES1370_REG_ADC_FRAMECNT >> 8);
 			bus_space_write_4(es->st, es->sh,
 					  ES1370_REG_ADC_FRAMECNT & 0xff,
-				  	  (ch->buffer->bufsize >> 2) - 1);
+				  	  (sndbuf_getsize(ch->buffer) >> 2) - 1);
 		} else es->ctrl &= ~CTRL_ADC_EN;
 	}
 	bus_space_write_4(es->st, es->sh, ES1370_REG_SERIAL_CONTROL, es->sctrl);
diff --git a/sys/dev/sound/pci/fm801.c b/sys/dev/sound/pci/fm801.c
index a01ea8e..33b9915 100644
--- a/sys/dev/sound/pci/fm801.c
+++ b/sys/dev/sound/pci/fm801.c
@@ -331,9 +331,8 @@ fm801ch_init(kobj_t obj, void *devinfo, snd_dbuf *b, pcm_channel *c, int dir)
 	ch->parent = fm801;
 	ch->channel = c;
 	ch->buffer = b;
-	ch->buffer->bufsize = FM801_BUFFSIZE;
 	ch->dir = dir;
-	if( chn_allocbuf(ch->buffer, fm801->parent_dmat) == -1) return NULL;
+	if (sndbuf_alloc(ch->buffer, fm801->parent_dmat, FM801_BUFFSIZE) == -1) return NULL;
 	return (void *)ch;
 }
 
@@ -435,7 +434,7 @@ fm801ch_trigger(kobj_t obj, void *data, int go)
 {
 	struct fm801_chinfo *ch = data;
 	struct fm801_info *fm801 = ch->parent;
-	u_int32_t baseaddr = vtophys(ch->buffer->buf);
+	u_int32_t baseaddr = vtophys(sndbuf_getbuf(ch->buffer));
 	snd_dbuf *b = ch->buffer;
 	u_int32_t k1;
 
diff --git a/sys/dev/sound/pci/maestro.c b/sys/dev/sound/pci/maestro.c
index 5955f77..82e84bf 100644
--- a/sys/dev/sound/pci/maestro.c
+++ b/sys/dev/sound/pci/maestro.c
@@ -85,6 +85,7 @@ struct agg_chinfo {
 	snd_dbuf		*buffer;
 	bus_addr_t		offset;
 	u_int32_t		blocksize;
+	u_int32_t		speed;
 	int			dir;
 	u_int			num;
 	u_int16_t		aputype;
@@ -518,9 +519,9 @@ aggch_start_dac(struct agg_chinfo *ch)
 {
 	u_int wpwa = APU_USE_SYSMEM | (ch->offset >> 9);
 	u_int size = AGG_BUFSIZ >> 1;
-	u_int speed = ch->channel->speed;
+	u_int speed = ch->speed;
 	u_int offset = ch->offset >> 1;
-	u_int cp = ch->buffer->rp >> 1;
+	u_int cp = 0;
 	u_int16_t apuch = ch->num << 1;
 	u_int dv;
 	int pan = 0;
@@ -613,7 +614,7 @@ calc_timer_freq(struct agg_chinfo *ch)
 	if (ch->aputype == APUTYPE_8BITLINEAR)
 		ss >>= 1;
 
-	return (ch->channel->speed * ss + ch->blocksize - 1) / ch->blocksize;
+	return (ch->speed * ss) / ch->blocksize;
 }
 
 static void
@@ -641,6 +642,7 @@ aggch_init(kobj_t obj, void *devinfo, snd_dbuf *b, pcm_channel *c, int dir)
 	struct agg_info *ess = devinfo;
 	struct agg_chinfo *ch;
 	bus_addr_t physaddr;
+	void *p;
 
 	ch = (dir == PCMDIR_PLAY)? ess->pch + ess->playchns : &ess->rch;
 
@@ -650,9 +652,10 @@ aggch_init(kobj_t obj, void *devinfo, snd_dbuf *b, pcm_channel *c, int dir)
 	ch->num = ess->playchns;
 	ch->dir = dir;
 
-	b->buf = dma_malloc(ess, AGG_BUFSIZ, &physaddr);
-	if (b->buf == NULL)
+	p = dma_malloc(ess, AGG_BUFSIZ, &physaddr);
+	if (p == NULL)
 		return NULL;
+	sndbuf_setup(b, p, AGG_BUFSIZ);
 
 	ch->offset = physaddr - ess->baseaddr;
 	if (physaddr < ess->baseaddr || ch->offset > WPWA_MAXADDR) {
@@ -663,7 +666,6 @@ aggch_init(kobj_t obj, void *devinfo, snd_dbuf *b, pcm_channel *c, int dir)
 		return NULL;
 	}
 
-	b->bufsize = AGG_BUFSIZ;
 	ch->wcreg_tpl = (physaddr - 16) & WAVCACHE_CHCTL_ADDRTAG_MASK;
 
 	if (dir == PCMDIR_PLAY) {
@@ -683,7 +685,7 @@ aggch_free(kobj_t obj, void *data)
 	struct agg_info *ess = ch->parent;
 
 	/* free up buffer - called after channel stopped */
-	dma_free(ess, ch->buffer->buf);
+	dma_free(ess, sndbuf_getbuf(ch->buffer));
 
 	/* return 0 if ok */
 	return 0;
@@ -719,7 +721,10 @@ aggch_setplayformat(kobj_t obj, void *data, u_int32_t format)
 static int
 aggch_setspeed(kobj_t obj, void *data, u_int32_t speed)
 {
-	return speed;
+	struct agg_chinfo *ch = data;
+
+	ch->speed = speed;
+	return ch->speed;
 }
 
 static int
diff --git a/sys/dev/sound/pci/neomagic.c b/sys/dev/sound/pci/neomagic.c
index 1e2760c..5a6ca8c 100644
--- a/sys/dev/sound/pci/neomagic.c
+++ b/sys/dev/sound/pci/neomagic.c
@@ -338,8 +338,7 @@ nmchan_init(kobj_t obj, void *devinfo, snd_dbuf *b, pcm_channel *c, int dir)
 	chnbuf = (dir == PCMDIR_PLAY)? sc->pbuf : sc->rbuf;
 	ch = (dir == PCMDIR_PLAY)? &sc->pch : &sc->rch;
 	ch->buffer = b;
-	ch->buffer->bufsize = NM_BUFFSIZE;
-	ch->buffer->buf = (u_int8_t *)rman_get_virtual(sc->buf) + chnbuf;
+	sndbuf_setup(ch->buffer, (u_int8_t *)rman_get_virtual(sc->buf) + chnbuf, NM_BUFFSIZE);
 	if (bootverbose)
 		device_printf(sc->dev, "%s buf %p\n", (dir == PCMDIR_PLAY)?
 			      "play" : "rec", ch->buffer->buf);
diff --git a/sys/dev/sound/pci/solo.c b/sys/dev/sound/pci/solo.c
index 7cb10f3..71a00f1 100644
--- a/sys/dev/sound/pci/solo.c
+++ b/sys/dev/sound/pci/solo.c
@@ -80,7 +80,7 @@ struct ess_chinfo {
 	pcm_channel *channel;
 	snd_dbuf *buffer;
 	int dir, hwch, stopping;
-	u_int32_t fmt, spd;
+	u_int32_t fmt, spd, blksz;
 };
 
 struct ess_info {
@@ -477,7 +477,7 @@ ess_start(struct ess_chinfo *ch)
 	struct ess_info *sc = ch->parent;
 
 	DEB(printf("ess_start\n"););
-	ess_setupch(sc, ch->hwch, ch->dir, ch->spd, ch->fmt, ch->buffer->dl);
+	ess_setupch(sc, ch->hwch, ch->dir, ch->spd, ch->fmt, ch->blksz);
 	ch->stopping = 0;
 	if (ch->hwch == 1) {
 		ess_write(sc, 0xb8, ess_read(sc, 0xb8) | 0x01);
@@ -519,9 +519,8 @@ esschan_init(kobj_t obj, void *devinfo, snd_dbuf *b, pcm_channel *c, int dir)
 	ch->parent = sc;
 	ch->channel = c;
 	ch->buffer = b;
-	ch->buffer->bufsize = ESS_BUFFSIZE;
 	ch->dir = dir;
-	if (chn_allocbuf(ch->buffer, sc->parent_dmat) == -1)
+	if (sndbuf_alloc(ch->buffer, sc->parent_dmat, ESS_BUFFSIZE) == -1)
 		return NULL;
 	ch->hwch = 1;
 	if ((dir == PCMDIR_PLAY) && (sc->duplex))
@@ -555,7 +554,10 @@ esschan_setspeed(kobj_t obj, void *data, u_int32_t speed)
 static int
 esschan_setblocksize(kobj_t obj, void *data, u_int32_t blocksize)
 {
-	return blocksize;
+	struct ess_chinfo *ch = data;
+
+	ch->blksz = blocksize;
+	return ch->blksz;
 }
 
 static int
@@ -570,7 +572,7 @@ esschan_trigger(kobj_t obj, void *data, int go)
 
 	switch (go) {
 	case PCMTRIG_START:
-		ess_dmasetup(sc, ch->hwch, vtophys(ch->buffer->buf), ch->buffer->bufsize, ch->dir);
+		ess_dmasetup(sc, ch->hwch, vtophys(sndbuf_getbuf(ch->buffer)), sndbuf_getsize(ch->buffer), ch->dir);
 		ess_dmatrigger(sc, ch->hwch, 1);
 		ess_start(ch);
 		break;
@@ -780,7 +782,7 @@ ess_dmapos(struct ess_info *sc, int ch)
 					i, p);
 			i = port_rd(sc->vc, 0x4, 2) + 1;
 			p = port_rd(sc->vc, 0x4, 2) + 1;
-		} while ((p > sc->dmasz[ch -1 ] || i < p || (p - i) > 0x8) && j++ < 1000);
+		} while ((p > sc->dmasz[ch - 1] || i < p || (p - i) > 0x8) && j++ < 1000);
 		ess_dmatrigger(sc, ch, 1);
 	}
 	else if (ch == 2)
diff --git a/sys/dev/sound/pci/t4dwave.c b/sys/dev/sound/pci/t4dwave.c
index dee0f9f..1dace66 100644
--- a/sys/dev/sound/pci/t4dwave.c
+++ b/sys/dev/sound/pci/t4dwave.c
@@ -52,7 +52,7 @@ struct tr_chinfo {
 	u_int32_t eso, delta;
 	u_int32_t rvol, cvol;
 	u_int32_t gvsel, pan, vol, ctrl;
-	int index, ss;
+	int index;
 	snd_dbuf *buffer;
 	pcm_channel *channel;
 	struct tr_info *parent;
@@ -391,10 +391,9 @@ trchan_init(kobj_t obj, void *devinfo, snd_dbuf *b, pcm_channel *c, int dir)
 		ch->index = -1;
 	}
 	ch->buffer = b;
-	ch->buffer->bufsize = TR_BUFFSIZE;
 	ch->parent = tr;
 	ch->channel = c;
-	if (chn_allocbuf(ch->buffer, tr->parent_dmat) == -1) return NULL;
+	if (sndbuf_alloc(ch->buffer, tr->parent_dmat, TR_BUFFSIZE) == -1) return NULL;
 	else return ch;
 }
 
@@ -405,9 +404,9 @@ trchan_setdir(kobj_t obj, void *data, int dir)
 	struct tr_info *tr = ch->parent;
 	if (dir == PCMDIR_PLAY && ch->index >= 0) {
 		ch->fmc = ch->fms = ch->ec = ch->alpha = 0;
-		ch->lba = vtophys(ch->buffer->buf);
+		ch->lba = vtophys(sndbuf_getbuf(ch->buffer));
 		ch->cso = 0;
-		ch->eso = ch->buffer->bufsize - 1;
+		ch->eso = sndbuf_getsize(ch->buffer) - 1;
 		ch->rvol = ch->cvol = 0;
 		ch->gvsel = 0;
 		ch->pan = 0;
@@ -423,10 +422,10 @@ trchan_setdir(kobj_t obj, void *data, int dir)
 		i = tr_rd(tr, TR_REG_DMAR11, 1) & 0x03;
 		tr_wr(tr, TR_REG_DMAR11, i | 0x54, 1);
 		/* set up base address */
-	   	tr_wr(tr, TR_REG_DMAR0, vtophys(ch->buffer->buf), 4);
+	   	tr_wr(tr, TR_REG_DMAR0, vtophys(sndbuf_getbuf(ch->buffer)), 4);
 		/* set up buffer size */
 		i = tr_rd(tr, TR_REG_DMAR4, 4) & ~0x00ffffff;
-		tr_wr(tr, TR_REG_DMAR4, i | (ch->buffer->bufsize - 1), 4);
+		tr_wr(tr, TR_REG_DMAR4, i | (sndbuf_getsize(ch->buffer) - 1), 4);
 	} else return -1;
 	return 0;
 }
@@ -438,12 +437,9 @@ trchan_setformat(kobj_t obj, void *data, u_int32_t format)
 	struct tr_info *tr = ch->parent;
 	u_int32_t bits = tr_fmttobits(format);
 
-	ch->ss = 1;
-	ch->ss <<= (format & AFMT_STEREO)? 1 : 0;
-	ch->ss <<= (format & AFMT_16BIT)? 1 : 0;
 	if (ch->index >= 0) {
 		tr_rdch(tr, ch->index, ch);
-		ch->eso = (ch->buffer->bufsize / ch->ss) - 1;
+		ch->eso = (sndbuf_getsize(ch->buffer) / sndbuf_getbps(ch->buffer)) - 1;
 		ch->ctrl = bits | 0x01;
    		tr_wrch(tr, ch->index, ch);
 	} else {
@@ -482,7 +478,7 @@ static int
 trchan_setblocksize(kobj_t obj, void *data, u_int32_t blocksize)
 {
 	struct tr_chinfo *ch = data;
-	return ch->buffer->bufsize / 2;
+	return sndbuf_getsize(ch->buffer) / 2;
 }
 
 static int
@@ -516,8 +512,8 @@ trchan_getptr(kobj_t obj, void *data)
 
 	if (ch->index >= 0) {
 		tr_rdch(tr, ch->index, ch);
-		return ch->cso * ch->ss;
-	} else return tr_rd(tr, TR_REG_DMAR0, 4) - vtophys(ch->buffer->buf);
+		return ch->cso * sndbuf_getbps(ch->buffer);
+	} else return tr_rd(tr, TR_REG_DMAR0, 4) - vtophys(sndbuf_getbuf(ch->buffer));
 }
 
 static pcmchan_caps *
diff --git a/sys/dev/sound/pci/via82c686.c b/sys/dev/sound/pci/via82c686.c
index 27d7aef..70dd9db 100644
--- a/sys/dev/sound/pci/via82c686.c
+++ b/sys/dev/sound/pci/via82c686.c
@@ -217,9 +217,8 @@ viachan_init(kobj_t obj, void *devinfo, snd_dbuf *b, pcm_channel *c, int dir)
 	ch->parent = via;
 	ch->channel = c;
 	ch->buffer = b;
-	b->bufsize = VIA_BUFFSIZE;
 
-	if (chn_allocbuf(ch->buffer, via->parent_dmat) == -1) return NULL;
+	if (sndbuf_alloc(ch->buffer, via->parent_dmat, VIA_BUFFSIZE) == -1) return NULL;
 	return ch;
 }
 
@@ -240,14 +239,14 @@ viachan_setdir(kobj_t obj, void *data, int dir)
 	 *  is feeding.
 	 */
 	ado = via->sgd_table;
-	chunk_size = ch->buffer->bufsize / SEGS_PER_CHAN;
+	chunk_size = sndbuf_getsize(ch->buffer) / SEGS_PER_CHAN;
 
 	if (dir == PCMDIR_REC) {
 		ado += SEGS_PER_CHAN;
 	}
 
 DEB(printf("SGD table located at va %p\n", ado));
-	phys_addr = vtophys(ch->buffer->buf);
+	phys_addr = vtophys(sndbuf_getbuf(ch->buffer));
 	for (i = 0; i < SEGS_PER_CHAN; i++) {
 		ado->ptr = phys_addr;
 		flag = (i == SEGS_PER_CHAN-1) ?
@@ -339,7 +338,7 @@ viachan_setblocksize(kobj_t obj, void *data, u_int32_t blocksize)
 {
 	struct via_chinfo *ch = data;
 
-	return ch->buffer->bufsize / 2;
+	return sndbuf_getsize(ch->buffer) / 2;
 }
 
 static int
@@ -409,7 +408,7 @@ DEB(printf("viachan_getptr: len / base = %x / %x\n", len, base));
 		if (seg == 0) seg = SEGS_PER_CHAN;
 
 		/* Now work out offset: seg less count */
-		ptr = seg * ch->buffer->bufsize / SEGS_PER_CHAN - len;
+		ptr = seg * sndbuf_getsize(ch->buffer) / SEGS_PER_CHAN - len;
 DEB(printf("return ptr=%d\n", ptr));
 		return ptr;
 	}
@@ -430,7 +429,7 @@ DEB(printf("viachan_getptr: len / base = %x / %x\n", len, base));
 		if (seg == 0) seg = SEGS_PER_CHAN;
 
 		/* Now work out offset: seg less count */
-		ptr = seg * ch->buffer->bufsize / SEGS_PER_CHAN - len;
+		ptr = seg * sndbuf_getsize(ch->buffer) / SEGS_PER_CHAN - len;
 
 		/* DMA appears to operate on memory 'lines' of 32 bytes	*/
 		/* so don't return any part line - it isn't in RAM yet	*/
diff --git a/sys/dev/sound/pcm/buffer.c b/sys/dev/sound/pcm/buffer.c
new file mode 100644
index 0000000..81b4037
--- /dev/null
+++ b/sys/dev/sound/pcm/buffer.c
@@ -0,0 +1,244 @@
+/*
+ * Copyright (c) 1999 Cameron Grant <gandalf@vilnya.demon.co.uk>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#include <dev/sound/pcm/sound.h>
+
+static void
+sndbuf_setmap(void *arg, bus_dma_segment_t *segs, int nseg, int error)
+{
+	snd_dbuf *b = (snd_dbuf *)arg;
+
+	if (bootverbose) {
+		printf("pcm: setmap %lx, %lx; ", (unsigned long)segs->ds_addr,
+		       (unsigned long)segs->ds_len);
+		printf("%p -> %lx\n", b->buf, (unsigned long)vtophys(b->buf));
+	}
+}
+
+/*
+ * Allocate memory for DMA buffer. If the device do not perform DMA transfer,
+ * the driver can call malloc(9) by its own.
+ */
+int
+sndbuf_alloc(snd_dbuf *b, bus_dma_tag_t dmatag, int size)
+{
+	b->dmatag = dmatag;
+	b->maxsize = size;
+	b->bufsize = b->maxsize;
+	if (bus_dmamem_alloc(b->dmatag, (void **)&b->buf, BUS_DMA_NOWAIT, &b->dmamap))
+		return ENOSPC;
+	if (bus_dmamap_load(b->dmatag, b->dmamap, b->buf, b->maxsize, sndbuf_setmap, b, 0))
+		return ENOSPC;
+	return sndbuf_resize(b, 2, b->maxsize / 2);
+}
+
+int
+sndbuf_setup(snd_dbuf *b, void *buf, int size)
+{
+	bzero(b, sizeof(*b));
+	b->buf = buf;
+	b->maxsize = size;
+	b->bufsize = b->maxsize;
+	return sndbuf_resize(b, 2, b->maxsize / 2);
+}
+
+void
+sndbuf_free(snd_dbuf *b)
+{
+	bus_dmamap_unload(b->dmatag, b->dmamap);
+	bus_dmamem_free(b->dmatag, b->buf, b->dmamap);
+}
+
+int
+sndbuf_resize(snd_dbuf *b, int blkcnt, int blksz)
+{
+	if (blkcnt == 0)
+		blkcnt = b->blkcnt;
+	if (blksz == 0)
+		blksz = b->blksz;
+	if (blkcnt < 2 || blksz < 16 || (blkcnt * blksz > b->maxsize))
+		return EINVAL;
+	b->blkcnt = blkcnt;
+	b->blksz = blksz;
+	b->bufsize = blkcnt * blksz;
+	sndbuf_reset(b);
+	return 0;
+}
+
+void
+sndbuf_clear(snd_dbuf *b, int length)
+{
+	int i;
+	u_int16_t data, *p;
+
+	if (length == 0)
+		return;
+
+	if (b->fmt & AFMT_SIGNED)
+		data = 0x00;
+	else
+		data = 0x80;
+
+	if (b->fmt & AFMT_16BIT)
+		data <<= 8;
+	else
+		data |= data << 8;
+
+	if (b->fmt & AFMT_BIGENDIAN)
+		data = ((data >> 8) & 0x00ff) | ((data << 8) & 0xff00);
+
+	i = b->fp;
+	p = (u_int16_t *)(b->buf + b->fp);
+	while (length > 1) {
+		*p++ = data;
+		length -= 2;
+		i += 2;
+		if (i >= b->bufsize) {
+			p = (u_int16_t *)b->buf;
+			i = 0;
+		}
+	}
+	if (length == 1)
+		*(b->buf + i) = data & 0xff;
+}
+
+void
+sndbuf_reset(snd_dbuf *b)
+{
+	b->rp = b->fp = 0;
+	b->dl = b->rl = 0;
+	b->fl = b->bufsize;
+	b->prev_total = b->total = 0;
+	b->prev_int_count = b->int_count = 0;
+	b->underflow = 0;
+	if (b->buf && b->bufsize > 0)
+		sndbuf_clear(b, b->bufsize);
+}
+
+int
+sndbuf_setfmt(snd_dbuf *b, u_int32_t fmt)
+{
+	b->fmt = fmt;
+	b->bps = 1;
+	b->bps <<= (b->fmt & AFMT_STEREO)? 1 : 0;
+	b->bps <<= (b->fmt & AFMT_16BIT)? 1 : 0;
+	b->bps <<= (b->fmt & AFMT_32BIT)? 2 : 0;
+	return 0;
+}
+
+int
+sndbuf_getbps(snd_dbuf *b)
+{
+	return b->bps;
+}
+
+void *
+sndbuf_getbuf(snd_dbuf *b)
+{
+	return b->buf;
+}
+
+int
+sndbuf_getsize(snd_dbuf *b)
+{
+	return b->bufsize;
+}
+
+int
+sndbuf_runsz(snd_dbuf *b)
+{
+	return b->dl;
+}
+
+int
+sndbuf_isadmasetup(snd_dbuf *b, struct resource *drq)
+{
+	/* should do isa_dma_acquire/isa_dma_release here */
+	if (drq == NULL) {
+		b->flags &= ~SNDBUF_F_ISADMA;
+		b->chan = -1;
+	} else {
+		b->flags &= ~SNDBUF_F_ISADMA;
+		b->chan = rman_get_start(drq);
+	}
+	return 0;
+}
+
+int
+sndbuf_isadmasetdir(snd_dbuf *b, int dir)
+{
+	b->dir = (dir == PCMDIR_PLAY)? ISADMA_WRITE : ISADMA_READ;
+	return 0;
+}
+
+void
+sndbuf_isadma(snd_dbuf *b, int go)
+{
+	KASSERT(b, ("sndbuf_isadma called with b == NULL"));
+	KASSERT(ISA_DMA(b), ("sndbuf_isadma called on non-ISA channel"));
+
+	switch (go) {
+	case PCMTRIG_START:
+		/* isa_dmainit(b->chan, size); */
+		isa_dmastart(b->dir | ISADMA_RAW, b->buf, b->bufsize, b->chan);
+		break;
+
+	case PCMTRIG_STOP:
+	case PCMTRIG_ABORT:
+		isa_dmastop(b->chan);
+		isa_dmadone(b->dir | ISADMA_RAW, b->buf, b->bufsize, b->chan);
+		break;
+	}
+
+	DEB(printf("buf 0x%p ISA DMA %s, channel %d\n",
+		b,
+		(go == PCMTRIG_START)? "started" : "stopped",
+		b->chan));
+}
+
+int
+sndbuf_isadmaptr(snd_dbuf *b)
+{
+	if (ISA_DMA(b)) {
+		int i = b->dl? isa_dmastatus(b->chan) : b->bufsize;
+		if (i < 0)
+			i = 0;
+		return b->bufsize - i;
+    	} else KASSERT(1, ("sndbuf_isadmaptr called on invalid channel"));
+	return -1;
+}
+
+void
+sndbuf_isadmabounce(snd_dbuf *b)
+{
+	if (ISA_DMA(b)) {
+		/* tell isa_dma to bounce data in/out */
+    	} else
+		KASSERT(1, ("chn_isadmabounce called on invalid channel"));
+}
+
diff --git a/sys/dev/sound/pcm/buffer.h b/sys/dev/sound/pcm/buffer.h
new file mode 100644
index 0000000..62058ce
--- /dev/null
+++ b/sys/dev/sound/pcm/buffer.h
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 1999 Cameron Grant <gandalf@vilnya.demon.co.uk>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#define ISA_DMA(b) (((b)->chan >= 0 && (b)->chan != 4 && (b)->chan < 8))
+
+int sndbuf_alloc(snd_dbuf *b, bus_dma_tag_t dmatag, int size);
+int sndbuf_setup(snd_dbuf *b, void *buf, int size);
+void sndbuf_free(snd_dbuf *b);
+int sndbuf_resize(snd_dbuf *b, int blkcnt, int blksz);
+void sndbuf_reset(snd_dbuf *b);
+void sndbuf_clear(snd_dbuf *b, int length);
+int sndbuf_setfmt(snd_dbuf *b, u_int32_t fmt);
+int sndbuf_getbps(snd_dbuf *b);
+void *sndbuf_getbuf(snd_dbuf *b);
+int sndbuf_getsize(snd_dbuf *b);
+int sndbuf_runsz(snd_dbuf *b);
+
+int sndbuf_isadmasetup(snd_dbuf *b, struct resource *drq);
+int sndbuf_isadmasetdir(snd_dbuf *b, int dir);
+void sndbuf_isadma(snd_dbuf *b, int go);
+int sndbuf_isadmaptr(snd_dbuf *b);
+void sndbuf_isadmabounce(snd_dbuf *b);
+
+
diff --git a/sys/dev/sound/pcm/channel.c b/sys/dev/sound/pcm/channel.c
index 4030028..da4aa14 100644
--- a/sys/dev/sound/pcm/channel.c
+++ b/sys/dev/sound/pcm/channel.c
@@ -36,7 +36,6 @@ MALLOC_DEFINE(M_CHANNEL, "channel", "pcm channel");
 #define	DMA_ALIGN_THRESHOLD	4
 #define	DMA_ALIGN_MASK		(~(DMA_ALIGN_THRESHOLD - 1))
 
-#define ISA_DMA(b) (((b)->chan >= 0 && (b)->chan != 4 && (b)->chan < 8))
 #define CANCHANGE(c) (!(c)->buffer.dl)
 #define ROUND(x) ((x) & DMA_ALIGN_MASK)
 
@@ -44,7 +43,6 @@ MALLOC_DEFINE(M_CHANNEL, "channel", "pcm channel");
 #define DEB(x) x
 */
 
-static void buf_clear(snd_dbuf *b, u_int32_t fmt, int length);
 static void chn_dmaupdate(pcm_channel *c);
 static void chn_wrintr(pcm_channel *c);
 static void chn_rdintr(pcm_channel *c);
@@ -110,14 +108,6 @@ produced on overruns.
  * gets copied in or out of the real buffer.  fix requires mods to isa_dma.c
  * and possibly fixes to other autodma mode clients
  */
-static void
-chn_isadmabounce(pcm_channel *c)
-{
-	if (ISA_DMA(&c->buffer)) {
-		/* tell isa_dma to bounce data in/out */
-    	} else KASSERT(1, ("chn_isadmabounce called on invalid channel"));
-}
-
 static int
 chn_polltrigger(pcm_channel *c)
 {
@@ -156,7 +146,7 @@ chn_dmadone(pcm_channel *c)
 	else
 		chn_dmaupdate(c);
 	if (ISA_DMA(b))
-		chn_isadmabounce(c); /* sync bounce buffer */
+		sndbuf_isadmabounce(b); /* sync bounce buffer */
 	b->int_count++;
 }
 
@@ -286,7 +276,7 @@ chn_wrfeed(pcm_channel *c)
 		b->fl -= l;
 		b->fp = (b->fp + l) % b->bufsize;
 		/* Clear the new space in the secondary buffer. */
-		buf_clear(bs, bs->fmt, l);
+		sndbuf_clear(bs, l);
 		/* Accumulate the total bytes of the moved samples. */
 		lacc += l;
 		/* A feed to the DMA buffer is equivalent to an interrupt. */
@@ -389,7 +379,7 @@ chn_wrintr(pcm_channel *c)
 		chn_wrfeed(c);
 	else {
 		while (chn_wrfeed(c) > 0);
-		buf_clear(b, b->fmt, b->fl);
+		sndbuf_clear(b, b->fl);
 	}
 	chn_dmawakeup(c);
     	if (c->flags & CHN_F_TRIGGERED) {
@@ -414,7 +404,7 @@ chn_wrintr(pcm_channel *c)
 			 * we are near to underflow condition, so to prevent
 			 * audio 'clicks' clear next b->fl bytes
 			 */
-			buf_clear(b, b->fmt, b->fl);
+			sndbuf_clear(b, b->fl);
 			if (b->rl < DMA_ALIGN_THRESHOLD)
 				b->underflow = 1;
 		}
@@ -423,7 +413,7 @@ chn_wrintr(pcm_channel *c)
 		DEB(printf("underflow, flags 0x%08x rp %d rl %d\n", c->flags, b->rp, b->rl));
 		if (b->dl) { /* DMA was active */
 			b->underflow = 1; /* set underflow flag */
-			buf_clear(b, b->fmt, b->bufsize);
+			sndbuf_clear(b, b->bufsize);
 		}
     	}
 }
@@ -649,7 +639,7 @@ chn_rdfeed2nd(pcm_channel *c, struct uio *buf)
 		bs->rl -= w;
 		bs->rp = (bs->rp + w) % bs->bufsize;
 		/* Clear the new space in the secondary buffer. */
-		buf_clear(bs, bs->fmt, l);
+		sndbuf_clear(bs, l);
 		/* Accumulate the total bytes of the moved samples. */
 		bs->total += w;
 		wacc += w;
@@ -844,76 +834,6 @@ chn_start(pcm_channel *c, int force)
 	return r;
 }
 
-static void
-chn_dma_setmap(void *arg, bus_dma_segment_t *segs, int nseg, int error)
-{
-	snd_dbuf *b = (snd_dbuf *)arg;
-
-	if (bootverbose) {
-		printf("pcm: setmap %lx, %lx; ", (unsigned long)segs->ds_addr,
-		       (unsigned long)segs->ds_len);
-		printf("%p -> %lx\n", b->buf, (unsigned long)vtophys(b->buf));
-	}
-}
-
-/*
- * Allocate memory for DMA buffer. If the device do not perform DMA transfer,
- * the drvier can call malloc(9) by its own.
- */
-int
-chn_allocbuf(snd_dbuf *b, bus_dma_tag_t parent_dmat)
-{
-	b->parent_dmat = parent_dmat;
-	if (bus_dmamem_alloc(b->parent_dmat, (void **)&b->buf,
-			     BUS_DMA_NOWAIT, &b->dmamap)) return -1;
-	if (bus_dmamap_load(b->parent_dmat, b->dmamap, b->buf,
-			    b->bufsize, chn_dma_setmap, b, 0)) return -1;
-	return 0;
-}
-
-void
-chn_freebuf(snd_dbuf *b)
-{
-	bus_dmamem_free(b->parent_dmat, b->buf, b->dmamap);
-}
-
-static void
-buf_clear(snd_dbuf *b, u_int32_t fmt, int length)
-{
-	int i;
-	u_int16_t data, *p;
-
-	if (length == 0)
-		return;
-
-	if (fmt & AFMT_SIGNED)
-		data = 0x00;
-	else
-		data = 0x80;
-
-	if (fmt & AFMT_16BIT)
-		data <<= 8;
-	else
-		data |= data << 8;
-
-	if (fmt & AFMT_BIGENDIAN)
-		data = ((data >> 8) & 0x00ff) | ((data << 8) & 0xff00);
-
-	i = b->fp;
-	p = (u_int16_t *)(b->buf + b->fp);
-	while (length > 1) {
-		*p++ = data;
-		length -= 2;
-		i += 2;
-		if (i >= b->bufsize) {
-			p = (u_int16_t *)b->buf;
-			i = 0;
-		}
-	}
-	if (length == 1)
-		*(b->buf + i) = data & 0xff;
-}
-
 void
 chn_resetbuf(pcm_channel *c)
 {
@@ -921,59 +841,8 @@ chn_resetbuf(pcm_channel *c)
 	snd_dbuf *bs = &c->buffer2nd;
 
 	c->blocks = 0;
-	b->rp = b->fp = 0;
-	b->dl = b->rl = 0;
-	b->fl = b->bufsize;
-	b->prev_total = b->total = 0;
-	b->prev_int_count = b->int_count = 0;
-	b->underflow = 0;
-	if (b->buf && b->bufsize > 0)
-		buf_clear(b, b->fmt, b->bufsize);
-
-	bs->rp = bs->fp = 0;
-	bs->dl = bs->rl = 0;
-	bs->fl = bs->bufsize;
-	bs->prev_total = bs->total = 0;
-	bs->prev_int_count = bs->int_count = 0;
-	bs->underflow = 0;
-	if (bs->buf && bs->bufsize > 0)
-		buf_clear(bs, bs->fmt, bs->bufsize);
-}
-
-void
-buf_isadma(snd_dbuf *b, int go)
-{
-	KASSERT(b, ("buf_isadma called with b == NULL"));
-	KASSERT(ISA_DMA(b), ("buf_isadma called on non-ISA channel"));
-
-	switch (go) {
-	case PCMTRIG_START:
-		isa_dmastart(b->dir | ISADMA_RAW, b->buf, b->bufsize, b->chan);
-		break;
-
-	case PCMTRIG_STOP:
-	case PCMTRIG_ABORT:
-		isa_dmastop(b->chan);
-		isa_dmadone(b->dir | ISADMA_RAW, b->buf, b->bufsize, b->chan);
-		break;
-	}
-
-	DEB(printf("buf 0x%p ISA DMA %s, channel %d\n",
-		b,
-		(go == PCMTRIG_START)? "started" : "stopped",
-		b->chan));
-}
-
-int
-buf_isadmaptr(snd_dbuf *b)
-{
-	if (ISA_DMA(b)) {
-		int i = b->dl? isa_dmastatus(b->chan) : b->bufsize;
-		if (i < 0)
-			i = 0;
-		return b->bufsize - i;
-    	} else KASSERT(1, ("buf_isadmaptr called on invalid channel"));
-	return -1;
+	sndbuf_reset(b);
+	sndbuf_reset(bs);
 }
 
 /*
@@ -1132,9 +1001,6 @@ chn_reset(pcm_channel *c, u_int32_t fmt)
 	chn_abort(c);
 	c->flags &= CHN_F_RESET;
 	CHANNEL_RESET(c->methods, c->devinfo);
-	r = chn_setblocksize(c, CHN_2NDBUFBLKNUM, CHN_2NDBUFBLKSIZE);
-	if (r)
-		return r;
 	if (fmt) {
 		hwspd = DSP_DEFAULT_SPEED;
 		RANGE(hwspd, chn_getcaps(c)->minspeed, chn_getcaps(c)->maxspeed);
@@ -1146,6 +1012,9 @@ chn_reset(pcm_channel *c, u_int32_t fmt)
 		if (r == 0)
 			r = chn_setvolume(c, 100, 100);
 	}
+	r = chn_setblocksize(c, 0, 0);
+	if (r)
+		return r;
 	chn_resetbuf(c);
 	CHANNEL_RESETDONE(c->methods, c->devinfo);
 	/* c->flags |= CHN_F_INIT; */
@@ -1169,6 +1038,7 @@ int
 chn_init(pcm_channel *c, void *devinfo, int dir)
 {
 	struct feeder_class *fc;
+	snd_dbuf *b = &c->buffer;
 	snd_dbuf *bs = &c->buffer2nd;
 
 	/* Initialize the hardware and DMA buffer first. */
@@ -1191,6 +1061,8 @@ chn_init(pcm_channel *c, void *devinfo, int dir)
 
 	/* And the secondary buffer. */
 	bs->buf = NULL;
+	sndbuf_setfmt(b, AFMT_U8);
+	sndbuf_setfmt(bs, AFMT_U8);
 	bs->bufsize = 0;
 	return 0;
 }
@@ -1202,7 +1074,7 @@ chn_kill(pcm_channel *c)
 		chn_trigger(c, PCMTRIG_ABORT);
 	while (chn_removefeeder(c) == 0);
 	if (CHANNEL_FREE(c->methods, c->devinfo))
-		chn_freebuf(&c->buffer);
+		sndbuf_free(&c->buffer);
 	c->flags |= CHN_F_DEAD;
 	return 0;
 }
@@ -1236,44 +1108,59 @@ int
 chn_setspeed(pcm_channel *c, int speed)
 {
 	pcm_feeder *f;
-	int r, hwspd, delta;
+    	snd_dbuf *b = &c->buffer;
+    	snd_dbuf *bs = &c->buffer2nd;
+	int r, delta;
 
 	DEB(printf("want speed %d, ", speed));
 	if (speed <= 0)
 		return EINVAL;
 	if (CANCHANGE(c)) {
 		c->speed = speed;
-		hwspd = speed;
-		RANGE(hwspd, chn_getcaps(c)->minspeed, chn_getcaps(c)->maxspeed);
-		DEB(printf("try speed %d, ", hwspd));
-		hwspd = CHANNEL_SETSPEED(c->methods, c->devinfo, hwspd);
-		DEB(printf("got speed %d, ", hwspd));
-		delta = hwspd - speed;
+		b->spd = speed;
+		bs->spd = speed;
+		RANGE(b->spd, chn_getcaps(c)->minspeed, chn_getcaps(c)->maxspeed);
+		DEB(printf("try speed %d, ", b->spd));
+		b->spd = CHANNEL_SETSPEED(c->methods, c->devinfo, b->spd);
+		DEB(printf("got speed %d, ", b->spd));
+
+		delta = b->spd - bs->spd;
 		if (delta < 0)
 			delta = -delta;
+
 		c->feederflags &= ~(1 << FEEDER_RATE);
 		if (delta > 500)
 			c->feederflags |= 1 << FEEDER_RATE;
 		else
-			speed = hwspd;
+			bs->spd = b->spd;
+
 		r = chn_buildfeeder(c);
 		DEB(printf("r = %d\n", r));
 		if (r)
 			return r;
+
+		r = chn_setblocksize(c, 0, 0);
+		if (r)
+			return r;
+
 		if (!(c->feederflags & (1 << FEEDER_RATE)))
 			return 0;
+
 		f = chn_findfeeder(c, FEEDER_RATE);
 		DEB(printf("feedrate = %p\n", f));
 		if (f == NULL)
 			return EINVAL;
-		r = FEEDER_SET(f, FEEDRATE_SRC, speed);
-		DEB(printf("feeder_set(FEEDRATE_SRC, %d) = %d\n", speed, r));
+
+		r = FEEDER_SET(f, FEEDRATE_SRC, bs->spd);
+		DEB(printf("feeder_set(FEEDRATE_SRC, %d) = %d\n", bs->spd, r));
 		if (r)
 			return r;
-		r = FEEDER_SET(f, FEEDRATE_DST, hwspd);
-		DEB(printf("feeder_set(FEEDRATE_DST, %d) = %d\n", hwspd, r));
+
+		r = FEEDER_SET(f, FEEDRATE_DST, b->spd);
+		DEB(printf("feeder_set(FEEDRATE_DST, %d) = %d\n", b->spd, r));
 		if (r)
 			return r;
+
 		return 0;
 	}
 	c->speed = speed;
@@ -1287,8 +1174,8 @@ chn_setformat(pcm_channel *c, u_int32_t fmt)
 	snd_dbuf *b = &c->buffer;
 	snd_dbuf *bs = &c->buffer2nd;
 	int r;
-
 	u_int32_t hwfmt;
+
 	if (CANCHANGE(c)) {
 		DEB(printf("want format %d\n", fmt));
 		c->format = fmt;
@@ -1300,8 +1187,8 @@ chn_setformat(pcm_channel *c, u_int32_t fmt)
 		if (r)
 			return r;
 		hwfmt = c->feeder->desc->out;
-		b->fmt = hwfmt;
-		bs->fmt = hwfmt;
+		sndbuf_setfmt(b, hwfmt);
+		sndbuf_setfmt(bs, hwfmt);
 		chn_resetbuf(c);
 		CHANNEL_SETFORMAT(c->methods, c->devinfo, hwfmt);
 		return chn_setspeed(c, c->speed);
@@ -1316,54 +1203,65 @@ chn_setblocksize(pcm_channel *c, int blkcnt, int blksz)
 {
 	snd_dbuf *b = &c->buffer;
 	snd_dbuf *bs = &c->buffer2nd;
-	int s, ss, bufsz;
+	int s, bufsz, irqhz, tmp;
 
-	if (bs->blkcnt == blkcnt && bs->blksz == blksz)
-		return 0;
-    	if (c->flags & CHN_F_MAPPED) {
-		DEB(printf("chn_setblocksize: can't work on mapped channel"));
+	if (!CANCHANGE(c) || (c->flags & CHN_F_MAPPED))
 		return EINVAL;
-	}
-	c->flags &= ~CHN_F_HAS_SIZE;
-
-	ss = 1;
-	ss <<= (bs->fmt & AFMT_STEREO)? 1 : 0;
-	ss <<= (bs->fmt & AFMT_16BIT)? 1 : 0;
 
-	if (blksz >= 2)
+	if (blksz == 0 || blksz == -1) {
+		if (blksz == -1)
+			c->flags &= ~CHN_F_HAS_SIZE;
+		if (c->flags & CHN_F_HAS_SIZE)
+			return 0;
+		blksz = (bs->bps * bs->spd) / CHN_DEFAULT_HZ;
+	      	tmp = 32;
+		while (tmp <= blksz)
+			tmp <<= 1;
+		tmp >>= 1;
+		blksz = tmp;
+
+		RANGE(blksz, 16, CHN_2NDBUFMAXSIZE / 2);
+		RANGE(blkcnt, 2, CHN_2NDBUFMAXSIZE / blksz);
+	} else {
+		if ((blksz < 16) || (blkcnt < 2) || (blkcnt * blksz > CHN_2NDBUFMAXSIZE))
+			return EINVAL;
 		c->flags |= CHN_F_HAS_SIZE;
-	/* let us specify blksz without setting CHN_F_HAS_SIZE */
-	if (blksz < 0)
-		blksz = -blksz;
-	/* default to blksz = ~0.25s */
-	if (blksz < 16)
-		blksz = (ss * c->speed) >> 2;
-	if (blksz > CHN_2NDBUFMAXSIZE / 2)
-		blksz = CHN_2NDBUFMAXSIZE / 2;
-	if (blkcnt < 2)
-		blkcnt = 2;
-
-	if (blkcnt * blksz > CHN_2NDBUFMAXSIZE)
-		blkcnt = CHN_2NDBUFMAXSIZE / blksz;
+	}
+
 	bufsz = blkcnt * blksz;
 
 	s = spltty();
+
 	if (bs->buf != NULL)
 		free(bs->buf, M_DEVBUF);
 	bs->buf = malloc(bufsz, M_DEVBUF, M_WAITOK);
 	if (bs->buf == NULL) {
       		splx(s);
-		DEB(printf("chn_setblocksize: out of memory."));
+		DEB(printf("chn_setblocksize: out of memory\n"));
 		return ENOSPC;
 	}
+
 	bs->bufsize = bufsz;
-	bs->rl = bs->rp = bs->fp = 0;
-	bs->fl = bs->bufsize;
-	buf_clear(bs, bs->fmt, bs->bufsize);
 	bs->blkcnt = blkcnt;
 	bs->blksz = blksz;
+
+	/* adjust for different hw format/speed */
+	irqhz = (bs->bps * bs->spd) / bs->blksz;
+
+	b->blksz = (b->bps * b->spd) / irqhz;
+
+	/* round down to 2^x */
+	blksz = 32;
+	while (blksz <= b->blksz)
+		blksz <<= 1;
+	blksz >>= 1;
+
+	/* round down to fit hw buffer size */
 	RANGE(blksz, 16, b->bufsize / 2);
+
 	b->blksz = CHANNEL_SETBLOCKSIZE(c->methods, c->devinfo, blksz);
+
+	chn_resetbuf(c);
 	splx(s);
 
 	return 0;
@@ -1439,7 +1337,7 @@ chn_buildfeeder(pcm_channel *c)
 			desc.flags = 0;
 			DEB(printf("find feeder type %d, ", type));
 			fc = feeder_getclass(&desc);
-			DEB(printf("got %p\n", f));
+			DEB(printf("got %p\n", fc));
 			if (fc == NULL)
 				return EINVAL;
 			dst = fc->desc->in;
@@ -1454,7 +1352,7 @@ chn_buildfeeder(pcm_channel *c)
 			if (chn_addfeeder(c, fc, fc->desc))
 				return EINVAL;
 			src = fc->desc->out;
-			DEB(printf("added feeder %p, output %x\n", f, src));
+			DEB(printf("added feeder %p, output %x\n", fc, src));
 			dst = 0;
 			flags &= ~(1 << type);
 		}
diff --git a/sys/dev/sound/pcm/channel.h b/sys/dev/sound/pcm/channel.h
index 243c207..73c1b8c 100644
--- a/sys/dev/sound/pcm/channel.h
+++ b/sys/dev/sound/pcm/channel.h
@@ -49,8 +49,6 @@ int chn_getptr(pcm_channel *c);
 pcmchan_caps *chn_getcaps(pcm_channel *c);
 u_int32_t chn_getformats(pcm_channel *c);
 
-int chn_allocbuf(snd_dbuf *b, bus_dma_tag_t parent_dmat);
-void chn_freebuf(snd_dbuf *b);
 void chn_resetbuf(pcm_channel *c);
 void chn_intr(pcm_channel *c);
 void chn_checkunderflow(pcm_channel *c);
@@ -60,9 +58,6 @@ int chn_abort(pcm_channel *c);
 
 int fmtvalid(u_int32_t fmt, u_int32_t *fmtlist);
 
-void buf_isadma(snd_dbuf *b, int go);
-int buf_isadmaptr(snd_dbuf *b);
-
 #define PCMDIR_PLAY 1
 #define PCMDIR_REC -1
 
@@ -102,4 +97,6 @@ int buf_isadmaptr(snd_dbuf *b);
 /* The size of a whole secondary buffer. */
 #define CHN_2NDBUFMAXSIZE	(131072)
 
+#define	CHN_DEFAULT_HZ		50
+
 #define CHANNEL_DECLARE(name) static DEFINE_CLASS(name, name ## _methods, sizeof(struct kobj))
diff --git a/sys/dev/sound/pcm/datatypes.h b/sys/dev/sound/pcm/datatypes.h
index aaa17a3..55f4111 100644
--- a/sys/dev/sound/pcm/datatypes.h
+++ b/sys/dev/sound/pcm/datatypes.h
@@ -57,7 +57,7 @@ struct _snd_mixer {
 
 struct _snd_dbuf {
         u_int8_t *buf;
-        int bufsize;
+        int bufsize, maxsize;
         volatile int dl; /* transfer size */
         volatile int rp, fp; /* pointers to the ready and free area */
 	volatile int rl, fl; /* lenght of ready and free areas. */
@@ -65,12 +65,15 @@ struct _snd_dbuf {
 	volatile u_int32_t int_count, prev_int_count;
 	volatile u_int32_t total, prev_total;
 	int chan, dir;       /* dma channel */
-	int fmt, blksz, blkcnt;
+	int fmt, spd, bps;
+	int blksz, blkcnt;
 	int underflow, overrun;
+	u_int32_t flags;
 	bus_dmamap_t dmamap;
-	bus_dma_tag_t parent_dmat;
+	bus_dma_tag_t dmatag;
 	struct selinfo sel;
 };
+#define	SNDBUF_F_ISADMA		0x00000001
 
 /*****************************************************************************/
 
diff --git a/sys/dev/sound/pcm/dsp.c b/sys/dev/sound/pcm/dsp.c
index 59c14e9..9728afd 100644
--- a/sys/dev/sound/pcm/dsp.c
+++ b/sys/dev/sound/pcm/dsp.c
@@ -240,8 +240,10 @@ dsp_ioctl(snddev_info *d, int chan, u_long cmd, caddr_t arg)
     	case AIOGSIZE:	/* get the current blocksize */
 		{
 	    		struct snd_size *p = (struct snd_size *)arg;
-	    		if (wrch) p->play_size = wrch->buffer2nd.blksz;
-	    		if (rdch) p->rec_size = rdch->buffer2nd.blksz;
+	    		if (wrch)
+				p->play_size = wrch->buffer2nd.blksz;
+	    		if (rdch)
+				p->rec_size = rdch->buffer2nd.blksz;
 		}
 		break;
 
@@ -287,14 +289,16 @@ dsp_ioctl(snddev_info *d, int chan, u_long cmd, caddr_t arg)
 			if (rdch && wrch)
 				p->formats |= (d->flags & SD_F_SIMPLEX)? 0 : AFMT_FULLDUPLEX;
 	    		p->mixers = 1; /* default: one mixer */
-	    		p->inputs = d->mixer->devs;
+	    		p->inputs = mix_getdevs(d->mixer);
 	    		p->left = p->right = 100;
 		}
 		break;
 
     	case AIOSTOP:
-		if (*arg_i == AIOSYNC_PLAY && wrch) *arg_i = chn_abort(wrch);
-		else if (*arg_i == AIOSYNC_CAPTURE && rdch) *arg_i = chn_abort(rdch);
+		if (*arg_i == AIOSYNC_PLAY && wrch)
+			*arg_i = chn_abort(wrch);
+		else if (*arg_i == AIOSYNC_CAPTURE && rdch)
+			*arg_i = chn_abort(rdch);
 		else {
 	   	 	printf("AIOSTOP: bad channel 0x%x\n", *arg_i);
 	    		*arg_i = 0;
diff --git a/sys/dev/sound/pcm/mixer.c b/sys/dev/sound/pcm/mixer.c
index ddb161b..22e1d41 100644
--- a/sys/dev/sound/pcm/mixer.c
+++ b/sys/dev/sound/pcm/mixer.c
@@ -234,11 +234,11 @@ mixer_ioctl(snddev_info *d, u_long cmd, caddr_t arg)
     		case SOUND_MIXER_DEVMASK:
     		case SOUND_MIXER_CAPS:
     		case SOUND_MIXER_STEREODEVS:
-			v = m->devs;
+			v = mix_getdevs(m);
 			break;
 
     		case SOUND_MIXER_RECMASK:
-			v = m->recdevs;
+			v = mix_getrecdevs(m);
 			break;
 
     		case SOUND_MIXER_RECSRC:
diff --git a/sys/dev/sound/pcm/sound.h b/sys/dev/sound/pcm/sound.h
index 01cdb93..c3e77de 100644
--- a/sys/dev/sound/pcm/sound.h
+++ b/sys/dev/sound/pcm/sound.h
@@ -81,6 +81,7 @@ struct isa_device { int dummy; };
 
 #include <dev/sound/pcm/datatypes.h>
 #include <dev/sound/pcm/channel.h>
+#include <dev/sound/pcm/buffer.h>
 #include <dev/sound/pcm/feeder.h>
 #include <dev/sound/pcm/mixer.h>
 #include <dev/sound/pcm/dsp.h>