Conditionally enable the busfree interrupt to catch unexpected busfrees.

Immediate SCBs, since they always send messages that tell the target to
transition to bus free now rely on the busfree interrupt instead of the
IMMEDDONE sequencer interrupt that was generated before.

Rearrange some code in the message out loop to give ATN a little more time
to drop before we ACK the last byte.

Use SPIORDY instead of REQINIT when snooping for a tag message on a reconnect.
This is done for the same reasons we use SPIORDY in the inb functions.

When going into BITBUCKET mode, turn off HDMAEN in the DFCNTRL register so
that we can "not care" what the value of HCNT is.  If HCNT is 0, BITBUCKET
mode won't transfer any data if HDMAEN is set.  Seeing as we don't want the
transfer to even think about touching the host, this seems more sane anyway.
Thanks to "Dan Willis" <dan@plutotech.com> for pointing out that this was
a problem.

2 files changed, 29 insertions, 56 deletions

diff --git a/sys/dev/aic7xxx/aic7xxx.seq b/sys/dev/aic7xxx/aic7xxx.seq
index f25e8ea..56a4adb 100644
--- a/sys/dev/aic7xxx/aic7xxx.seq
+++ b/sys/dev/aic7xxx/aic7xxx.seq
@@ -39,7 +39,7 @@
  *
  *-M************************************************************************/
 
-VERSION AIC7XXX_SEQ_VER "$Id: aic7xxx.seq,v 1.49 1996/11/16 01:07:34 gibbs Exp $"
+VERSION AIC7XXX_SEQ_VER "$Id: aic7xxx.seq,v 1.50 1996/11/21 06:18:33 gibbs Exp $"
 
 #if defined(__NetBSD__)
 #include "../../../../dev/ic/aic7xxxreg.h"
@@ -82,9 +82,10 @@ A = ACCUM
 reset:
 	clr	DFCNTRL
 	clr	SCSISIGO		/* De-assert BSY */
-/*
- * We jump to start after every bus free.
- */
+
+p_busfree:
+	mvi	LASTPHASE, P_BUSFREE
+
 start:
 	and	FLAGS,0x07		/* clear target specific flags */
 	mvi	SCSISEQ,ENRSELI		/* Always allow reselection */
@@ -146,7 +147,7 @@ dma_queued_scb:
  * locks out on a per target basis instead of target/lun.  Although this
  * is not ideal for devices that have multiple luns active at the same
  * time, it is faster than looping through all SCB's looking for active
- * commands.  We also don't have enough spare SCB space for to store the
+ * commands.  We also don't have enough spare SCB space for us to store the
  * SCBID of the currently busy transaction for each target/lun making it
  * impossible to link up the SCBs.
  */
@@ -317,6 +318,12 @@ set_sxfrctl0:
 						 */
 	mvi	CLRSINT1,CLRBUSFREE
 	mvi	CLRSINT0,0x60			/* CLRSELDI|CLRSELDO */
+	or	SIMODE1, ENBUSFREE		/*
+						 * We aren't expecting a
+						 * bus free, so interrupt
+						 * the kernel driver if it
+						 * happens.
+						 */
 /*
  * Main loop for information transfer phases.  If BSY is false, then
  * we have a bus free condition, expected or not.  Otherwise, wait
@@ -400,6 +407,7 @@ data_phase_loop:
  * had an overrun.
  */
 	or	SXFRCTL1,BITBUCKET
+	and	DMAPARAMS, 0xf7		/* Turn off HDMAEN */
 	mvi	STCNT0,0xff
 	mvi	STCNT1,0xff
 	mvi	STCNT2,0xff
@@ -536,20 +544,20 @@ p_mesgout_start:
  * a MESSAGE REJECT.
  */
 p_mesgout_loop:
-	test	SSTAT1,BUSFREE	jnz p_mesgout_done
 	test	SSTAT0,SPIORDY jz p_mesgout_loop
 	test	SSTAT1,PHASEMIS	jnz p_mesgout_done
 /*
  * If the next bus phase after ATN drops is a message out, it means
  * that the target is requesting that the last message(s) be resent.
  */
+p_mesgout_dropatn:
+	cmp	DINDEX,1	jne p_mesgout_testretry	/* last byte? */
+	mvi	CLRSINT1,CLRATNO			/* drop ATN */
+p_mesgout_testretry:
 	test	DINDEX,0xff	jnz p_mesgout_outb
 	or	SCSISIGO,ATNO		/* turn on ATN for the retry */
 	jmp	p_mesgout_start
 p_mesgout_outb:
-	cmp	DINDEX,1	jne p_mesgout_outb2	/* last byte? */
-	mvi	CLRSINT1,CLRATNO			/* drop ATN */
-p_mesgout_outb2:
 	dec	DINDEX
 	mvi	CLRSINT0, CLRSPIORDY
 	mov	SCSIDATL,SINDIR
@@ -610,6 +618,10 @@ mesgin_complete:
  */
 
 /*
+ * We expect to go to bus free after this message.
+ */
+	and	SIMODE1, 0xf7		/* ~ENBUSFREE */
+/*
  * First check for residuals
  */
 	test	SCB_RESID_SGCNT,0xff	jnz upload_scb
@@ -627,7 +639,7 @@ check_status:
 
 status_ok:
 /* First, mark this target as free. */
-	test	SCB_CONTROL,TAG_ENB jnz test_immediate	/*
+	test	SCB_CONTROL,TAG_ENB jnz complete	/*
 							 * Tagged commands
 							 * don't busy the
 							 * target.
@@ -638,15 +650,6 @@ status_ok:
 	mov	DINDIR, SAVED_LINKPTR
 	mov	SCBPTR, SAVED_SCBPTR
 
-test_immediate:
-	test    SCB_CMDLEN,0xff jnz complete  /* Immediate message complete */
-/*
- * Pause the sequencer until the driver gets around to handling the command
- * complete.  This is so that any action that might require carefull timing
- * with the completion of this command can occur.
- */
-	mvi	INTSTAT,IMMEDDONE
-	jmp	dma_next_scb
 complete:
 	test	FLAGS, PAGESCBS jz complete_post
 	mov	A, QFULLCNT
@@ -661,7 +664,7 @@ complete_post:
 	mvi	INTSTAT,CMDCMPLT
 
 dma_next_scb:
-	cmp	SCB_LINKED_NEXT, SCB_LIST_NULL	je mesgin_done
+	cmp	SCB_LINKED_NEXT, SCB_LIST_NULL	je add_to_free_list
 	test	FLAGS, PAGESCBS jnz dma_next_scb2
 	/* Only DMA on top of ourselves if we are the SCB to download */
 	mov	A, SCB_LINKED_NEXT
@@ -674,7 +677,9 @@ dma_next_scb2:
 add_to_waiting_list:
 	mov	SCB_NEXT,WAITING_SCBH
 	mov	WAITING_SCBH, SCBPTR
-	or	FLAGS, SCB_LISTED
+	jmp	mesgin_done
+add_to_free_list:
+	call	add_scb_to_free_list
 	jmp	mesgin_done
 
 /*
@@ -706,10 +711,10 @@ mesgin_extended_intr:
  * and await the bus going free.
  */
 mesgin_disconnect:
+	and	SIMODE1, 0xf7		/* ~ENBUSFREE */
 	or	SCB_CONTROL,DISCONNECTED
 	test	FLAGS, PAGESCBS jz mesgin_done
 	call	add_scb_to_disc_list
-	or	FLAGS, SCB_LISTED
 	jmp	mesgin_done
 
 /*
@@ -772,8 +777,7 @@ mesgin_identify:
  */
 	mvi	ARG_1,SCB_LIST_NULL	/* Default to no-tag */
 snoop_tag_loop:
-	test	SSTAT1,BUSFREE		jnz use_findSCB
-	test	SSTAT1,REQINIT		jz snoop_tag_loop
+	test	SSTAT0,SPIORDY		jz snoop_tag_loop
 	test	SSTAT1,PHASEMIS		jnz use_findSCB
 	mvi	A			call inb_first
 	cmp	A,MSG_SIMPLE_Q_TAG	jne use_findSCB
@@ -834,28 +838,6 @@ mesgin_reject:
  */
 
 /*
- * Bus free phase.  It might be useful to interrupt the device
- * driver if we aren't expecting this.
- */
-p_busfree:
-	mvi	LASTPHASE, P_BUSFREE
-
-/*
- * if this is an immediate command, perform a psuedo command complete to
- * notify the driver.
- */
-	test	SCB_CMDLEN,0xff	jz status_ok
-	test	FLAGS, SCB_LISTED	jnz start
-	/*
-	 * This SCB didn't disconnect or have a command complete,
-	 * so put it on the free queue.  It was probably the
-	 * result of an abort of some sort.  This prevents us
-	 * from "leaking" SCBs.
-	 */
-	call	add_scb_to_free_list
-	jmp	start
-
-/*
  * Locking the driver out, build a one-byte message passed in SINDEX
  * if there is no active message already.  SINDEX is returned intact.
  */
diff --git a/sys/dev/aic7xxx/aic7xxx_reg.h b/sys/dev/aic7xxx/aic7xxx_reg.h
index 841abbf..0657b72 100644
--- a/sys/dev/aic7xxx/aic7xxx_reg.h
+++ b/sys/dev/aic7xxx/aic7xxx_reg.h
@@ -28,7 +28,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id: aic7xxx_reg.h,v 1.16 1996/11/11 05:16:41 gibbs Exp $
+ *	$Id: aic7xxx_reg.h,v 1.17 1996/11/16 01:07:35 gibbs Exp $
  */
 
 /*
@@ -420,10 +420,6 @@
                                                  * it that it can fill the
                                                  * message buffer.
                                                  */
-#define			IMMEDDONE	0xb1	/*
-						 * An immediate command has
-						 * completed
-						 */
 #define			MSG_BUFFER_BUSY	0xc1	/*
 						 * Sequencer wants to use the
 						 * message buffer, but it
@@ -571,11 +567,7 @@
 #define	SCB_ACTIVE2		0x0be
 #define	SCB_ACTIVE3		0x0bf
 
-#ifdef __linux__
-#define	SG_SIZEOF		0x0c		/* sizeof(struct scatterlist) */
-#else
 #define	SG_SIZEOF		0x08		/* sizeof(struct ahc_dma) */
-#endif
 
 /* --------------------- AHA-2840-only definitions -------------------- */
 
@@ -711,7 +703,6 @@
 #define		TWIN_BUS	0x01
 #define		WIDE_BUS	0x02
 #define		PAGESCBS	0x04
-#define		SCB_LISTED	0x08
 #define		DPHASE		0x10
 #define		TAGGED_SCB	0x20
 #define		IDENTIFY_SEEN	0x40