4 files changed, 193 insertions, 99 deletions

diff --git a/sound/usb/6fire/control.c b/sound/usb/6fire/control.c
index 2484635..ac828ef 100644
--- a/sound/usb/6fire/control.c
+++ b/sound/usb/6fire/control.c
@@ -65,6 +65,15 @@ init_data[] = {
 	{ 0 } /* TERMINATING ENTRY */
 };
 
+static const int rates_altsetting[] = { 1, 1, 2, 2, 3, 3 };
+/* values to write to soundcard register for all samplerates */
+static const u16 rates_6fire_vl[] = {0x00, 0x01, 0x00, 0x01, 0x00, 0x01};
+static const u16 rates_6fire_vh[] = {0x11, 0x11, 0x10, 0x10, 0x00, 0x00};
+
+enum {
+	DIGITAL_THRU_ONLY_SAMPLERATE = 3
+};
+
 static void usb6fire_control_master_vol_update(struct control_runtime *rt)
 {
 	struct comm_runtime *comm_rt = rt->chip->comm;
@@ -95,6 +104,67 @@ static void usb6fire_control_opt_coax_update(struct control_runtime *rt)
 	}
 }
 
+static int usb6fire_control_set_rate(struct control_runtime *rt, int rate)
+{
+	int ret;
+	struct usb_device *device = rt->chip->dev;
+	struct comm_runtime *comm_rt = rt->chip->comm;
+
+	if (rate < 0 || rate >= CONTROL_N_RATES)
+		return -EINVAL;
+
+	ret = usb_set_interface(device, 1, rates_altsetting[rate]);
+	if (ret < 0)
+		return ret;
+
+	/* set soundcard clock */
+	ret = comm_rt->write16(comm_rt, 0x02, 0x01, rates_6fire_vl[rate],
+			rates_6fire_vh[rate]);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static int usb6fire_control_set_channels(
+	struct control_runtime *rt, int n_analog_out,
+	int n_analog_in, bool spdif_out, bool spdif_in)
+{
+	int ret;
+	struct comm_runtime *comm_rt = rt->chip->comm;
+
+	/* enable analog inputs and outputs
+	 * (one bit per stereo-channel) */
+	ret = comm_rt->write16(comm_rt, 0x02, 0x02,
+			(1 << (n_analog_out / 2)) - 1,
+			(1 << (n_analog_in / 2)) - 1);
+	if (ret < 0)
+		return ret;
+
+	/* disable digital inputs and outputs */
+	/* TODO: use spdif_x to enable/disable digital channels */
+	ret = comm_rt->write16(comm_rt, 0x02, 0x03, 0x00, 0x00);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static int usb6fire_control_streaming_update(struct control_runtime *rt)
+{
+	struct comm_runtime *comm_rt = rt->chip->comm;
+
+	if (comm_rt) {
+		if (!rt->usb_streaming && rt->digital_thru_switch)
+			usb6fire_control_set_rate(rt,
+				DIGITAL_THRU_ONLY_SAMPLERATE);
+		return comm_rt->write16(comm_rt, 0x02, 0x00, 0x00,
+			(rt->usb_streaming ? 0x01 : 0x00) |
+			(rt->digital_thru_switch ? 0x08 : 0x00));
+	}
+	return -EINVAL;
+}
+
 static int usb6fire_control_master_vol_info(struct snd_kcontrol *kcontrol,
 		struct snd_ctl_elem_info *uinfo)
 {
@@ -195,6 +265,28 @@ static int usb6fire_control_opt_coax_get(struct snd_kcontrol *kcontrol,
 	return 0;
 }
 
+static int usb6fire_control_digital_thru_put(struct snd_kcontrol *kcontrol,
+		struct snd_ctl_elem_value *ucontrol)
+{
+	struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
+	int changed = 0;
+
+	if (rt->digital_thru_switch != ucontrol->value.integer.value[0]) {
+		rt->digital_thru_switch = ucontrol->value.integer.value[0];
+		usb6fire_control_streaming_update(rt);
+		changed = 1;
+	}
+	return changed;
+}
+
+static int usb6fire_control_digital_thru_get(struct snd_kcontrol *kcontrol,
+		struct snd_ctl_elem_value *ucontrol)
+{
+	struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
+	ucontrol->value.integer.value[0] = rt->digital_thru_switch;
+	return 0;
+}
+
 static struct __devinitdata snd_kcontrol_new elements[] = {
 	{
 		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
@@ -223,6 +315,15 @@ static struct __devinitdata snd_kcontrol_new elements[] = {
 		.get = usb6fire_control_opt_coax_get,
 		.put = usb6fire_control_opt_coax_put
 	},
+	{
+		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+		.name = "Digital Thru Playback Route",
+		.index = 0,
+		.access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
+		.info = snd_ctl_boolean_mono_info,
+		.get = usb6fire_control_digital_thru_get,
+		.put = usb6fire_control_digital_thru_put
+	},
 	{}
 };
 
@@ -238,6 +339,9 @@ int __devinit usb6fire_control_init(struct sfire_chip *chip)
 		return -ENOMEM;
 
 	rt->chip = chip;
+	rt->update_streaming = usb6fire_control_streaming_update;
+	rt->set_rate = usb6fire_control_set_rate;
+	rt->set_channels = usb6fire_control_set_channels;
 
 	i = 0;
 	while (init_data[i].type) {
@@ -249,6 +353,7 @@ int __devinit usb6fire_control_init(struct sfire_chip *chip)
 	usb6fire_control_opt_coax_update(rt);
 	usb6fire_control_line_phono_update(rt);
 	usb6fire_control_master_vol_update(rt);
+	usb6fire_control_streaming_update(rt);
 
 	i = 0;
 	while (elements[i].name) {
diff --git a/sound/usb/6fire/control.h b/sound/usb/6fire/control.h
index b534c77..8f5aeea 100644
--- a/sound/usb/6fire/control.h
+++ b/sound/usb/6fire/control.h
@@ -21,12 +21,29 @@ enum {
 	CONTROL_MAX_ELEMENTS = 32
 };
 
+enum {
+	CONTROL_RATE_44KHZ,
+	CONTROL_RATE_48KHZ,
+	CONTROL_RATE_88KHZ,
+	CONTROL_RATE_96KHZ,
+	CONTROL_RATE_176KHZ,
+	CONTROL_RATE_192KHZ,
+	CONTROL_N_RATES
+};
+
 struct control_runtime {
+	int (*update_streaming)(struct control_runtime *rt);
+	int (*set_rate)(struct control_runtime *rt, int rate);
+	int (*set_channels)(struct control_runtime *rt, int n_analog_out,
+		int n_analog_in, bool spdif_out, bool spdif_in);
+
 	struct sfire_chip *chip;
 
 	struct snd_kcontrol *element[CONTROL_MAX_ELEMENTS];
 	bool opt_coax_switch;
 	bool line_phono_switch;
+	bool digital_thru_switch;
+	bool usb_streaming;
 	u8 master_vol;
 };
 
diff --git a/sound/usb/6fire/firmware.c b/sound/usb/6fire/firmware.c
index 86c1a31..d47beff 100644
--- a/sound/usb/6fire/firmware.c
+++ b/sound/usb/6fire/firmware.c
@@ -3,12 +3,6 @@
  *
  * Firmware loader
  *
- * Currently not working for all devices. To be able to use the device
- * in linux, it is also possible to let the windows driver upload the firmware.
- * For that, start the computer in windows and reboot.
- * As long as the device is connected to the power supply, no firmware reload
- * needs to be performed.
- *
  * Author:	Torsten Schenk <torsten.schenk@zoho.com>
  * Created:	Jan 01, 2011
  * Version:	0.3.0
@@ -21,6 +15,7 @@
  */
 
 #include <linux/firmware.h>
+#include <linux/bitrev.h>
 
 #include "firmware.h"
 #include "chip.h"
@@ -33,32 +28,6 @@ enum {
 	FPGA_BUFSIZE = 512, FPGA_EP = 2
 };
 
-static const u8 BIT_REVERSE_TABLE[256] = {
-	0x00, 0x80, 0x40, 0xc0, 0x20, 0xa0, 0x60, 0xe0, 0x10, 0x90, 0x50,
-	0xd0, 0x30, 0xb0, 0x70, 0xf0, 0x08, 0x88, 0x48, 0xc8, 0x28, 0xa8,
-	0x68, 0xe8, 0x18, 0x98, 0x58, 0xd8, 0x38, 0xb8, 0x78, 0xf8, 0x04,
-	0x84, 0x44, 0xc4, 0x24, 0xa4, 0x64, 0xe4, 0x14, 0x94, 0x54, 0xd4,
-	0x34, 0xb4, 0x74, 0xf4, 0x0c, 0x8c, 0x4c, 0xcc, 0x2c, 0xac, 0x6c,
-	0xec, 0x1c, 0x9c, 0x5c, 0xdc, 0x3c, 0xbc, 0x7c, 0xfc, 0x02, 0x82,
-	0x42, 0xc2, 0x22, 0xa2, 0x62, 0xe2, 0x12, 0x92, 0x52, 0xd2, 0x32,
-	0xb2, 0x72, 0xf2, 0x0a, 0x8a, 0x4a, 0xca, 0x2a, 0xaa, 0x6a, 0xea,
-	0x1a, 0x9a, 0x5a, 0xda, 0x3a, 0xba, 0x7a, 0xfa, 0x06, 0x86, 0x46,
-	0xc6, 0x26, 0xa6, 0x66, 0xe6, 0x16, 0x96, 0x56, 0xd6, 0x36, 0xb6,
-	0x76, 0xf6, 0x0e, 0x8e, 0x4e, 0xce, 0x2e, 0xae, 0x6e, 0xee, 0x1e,
-	0x9e, 0x5e, 0xde, 0x3e, 0xbe, 0x7e, 0xfe, 0x01, 0x81, 0x41, 0xc1,
-	0x21, 0xa1, 0x61, 0xe1, 0x11, 0x91, 0x51, 0xd1, 0x31, 0xb1, 0x71,
-	0xf1, 0x09, 0x89, 0x49, 0xc9, 0x29, 0xa9, 0x69, 0xe9, 0x19, 0x99,
-	0x59, 0xd9, 0x39, 0xb9, 0x79, 0xf9, 0x05, 0x85, 0x45, 0xc5, 0x25,
-	0xa5, 0x65, 0xe5, 0x15, 0x95, 0x55, 0xd5, 0x35, 0xb5, 0x75, 0xf5,
-	0x0d, 0x8d, 0x4d, 0xcd, 0x2d, 0xad, 0x6d, 0xed, 0x1d, 0x9d, 0x5d,
-	0xdd, 0x3d, 0xbd, 0x7d, 0xfd, 0x03, 0x83, 0x43, 0xc3, 0x23, 0xa3,
-	0x63, 0xe3, 0x13, 0x93, 0x53, 0xd3, 0x33, 0xb3, 0x73, 0xf3, 0x0b,
-	0x8b, 0x4b, 0xcb, 0x2b, 0xab, 0x6b, 0xeb, 0x1b, 0x9b, 0x5b, 0xdb,
-	0x3b, 0xbb, 0x7b, 0xfb, 0x07, 0x87, 0x47, 0xc7, 0x27, 0xa7, 0x67,
-	0xe7, 0x17, 0x97, 0x57, 0xd7, 0x37, 0xb7, 0x77, 0xf7, 0x0f, 0x8f,
-	0x4f, 0xcf, 0x2f, 0xaf, 0x6f, 0xef, 0x1f, 0x9f, 0x5f, 0xdf, 0x3f,
-	0xbf, 0x7f, 0xff };
-
 /*
  * wMaxPacketSize of pcm endpoints.
  * keep synced with rates_in_packet_size and rates_out_packet_size in pcm.c
@@ -72,6 +41,10 @@ static const u8 ep_w_max_packet_size[] = {
 	0x94, 0x01, 0x5c, 0x02  /* alt 3: 404 EP2 and 604 EP6 (25 fpp) */
 };
 
+static const u8 known_fw_versions[][4] = {
+	{ 0x03, 0x01, 0x0b, 0x00 }
+};
+
 struct ihex_record {
 	u16 address;
 	u8 len;
@@ -340,7 +313,7 @@ static int usb6fire_fw_fpga_upload(
 
 	while (c != end) {
 		for (i = 0; c != end && i < FPGA_BUFSIZE; i++, c++)
-			buffer[i] = BIT_REVERSE_TABLE[(u8) *c];
+			buffer[i] = byte_rev_table[(u8) *c];
 
 		ret = usb6fire_fw_fpga_write(device, buffer, i);
 		if (ret < 0) {
@@ -363,6 +336,25 @@ static int usb6fire_fw_fpga_upload(
 	return 0;
 }
 
+/* check, if the firmware version the devices has currently loaded
+ * is known by this driver. 'version' needs to have 4 bytes version
+ * info data. */
+static int usb6fire_fw_check(u8 *version)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(known_fw_versions); i++)
+		if (!memcmp(version, known_fw_versions + i, 4))
+			return 0;
+
+	snd_printk(KERN_ERR PREFIX "invalid fimware version in device: "
+			"%02x %02x %02x %02x. "
+			"please reconnect to power. if this failure "
+			"still happens, check your firmware installation.",
+			version[0], version[1], version[2], version[3]);
+	return -EINVAL;
+}
+
 int usb6fire_fw_init(struct usb_interface *intf)
 {
 	int i;
@@ -378,9 +370,7 @@ int usb6fire_fw_init(struct usb_interface *intf)
 				"firmware state.\n");
 		return ret;
 	}
-	if (buffer[0] != 0xeb || buffer[1] != 0xaa || buffer[2] != 0x55
-			|| buffer[4] != 0x03 || buffer[5] != 0x01 || buffer[7]
-			!= 0x00) {
+	if (buffer[0] != 0xeb || buffer[1] != 0xaa || buffer[2] != 0x55) {
 		snd_printk(KERN_ERR PREFIX "unknown device firmware state "
 				"received from device: ");
 		for (i = 0; i < 8; i++)
@@ -389,7 +379,7 @@ int usb6fire_fw_init(struct usb_interface *intf)
 		return -EIO;
 	}
 	/* do we need fpga loader ezusb firmware? */
-	if (buffer[3] == 0x01 && buffer[6] == 0x19) {
+	if (buffer[3] == 0x01) {
 		ret = usb6fire_fw_ezusb_upload(intf,
 				"6fire/dmx6firel2.ihx", 0, NULL, 0);
 		if (ret < 0)
@@ -397,7 +387,10 @@ int usb6fire_fw_init(struct usb_interface *intf)
 		return FW_NOT_READY;
 	}
 	/* do we need fpga firmware and application ezusb firmware? */
-	else if (buffer[3] == 0x02 && buffer[6] == 0x0b) {
+	else if (buffer[3] == 0x02) {
+		ret = usb6fire_fw_check(buffer + 4);
+		if (ret < 0)
+			return ret;
 		ret = usb6fire_fw_fpga_upload(intf, "6fire/dmx6firecf.bin");
 		if (ret < 0)
 			return ret;
@@ -410,8 +403,8 @@ int usb6fire_fw_init(struct usb_interface *intf)
 		return FW_NOT_READY;
 	}
 	/* all fw loaded? */
-	else if (buffer[3] == 0x03 && buffer[6] == 0x0b)
-		return 0;
+	else if (buffer[3] == 0x03)
+		return usb6fire_fw_check(buffer + 4);
 	/* unknown data? */
 	else {
 		snd_printk(KERN_ERR PREFIX "unknown device firmware state "
diff --git a/sound/usb/6fire/pcm.c b/sound/usb/6fire/pcm.c
index ba62c74..b137b25 100644
--- a/sound/usb/6fire/pcm.c
+++ b/sound/usb/6fire/pcm.c
@@ -17,26 +17,23 @@
 #include "pcm.h"
 #include "chip.h"
 #include "comm.h"
+#include "control.h"
 
 enum {
 	OUT_N_CHANNELS = 6, IN_N_CHANNELS = 4
 };
 
 /* keep next two synced with
- * FW_EP_W_MAX_PACKET_SIZE[] and RATES_MAX_PACKET_SIZE */
+ * FW_EP_W_MAX_PACKET_SIZE[] and RATES_MAX_PACKET_SIZE
+ * and CONTROL_RATE_XXX in control.h */
 static const int rates_in_packet_size[] = { 228, 228, 420, 420, 404, 404 };
 static const int rates_out_packet_size[] = { 228, 228, 420, 420, 604, 604 };
 static const int rates[] = { 44100, 48000, 88200, 96000, 176400, 192000 };
-static const int rates_altsetting[] = { 1, 1, 2, 2, 3, 3 };
 static const int rates_alsaid[] = {
 	SNDRV_PCM_RATE_44100, SNDRV_PCM_RATE_48000,
 	SNDRV_PCM_RATE_88200, SNDRV_PCM_RATE_96000,
 	SNDRV_PCM_RATE_176400, SNDRV_PCM_RATE_192000 };
 
-/* values to write to soundcard register for all samplerates */
-static const u16 rates_6fire_vl[] = {0x00, 0x01, 0x00, 0x01, 0x00, 0x01};
-static const u16 rates_6fire_vh[] = {0x11, 0x11, 0x10, 0x10, 0x00, 0x00};
-
 enum { /* settings for pcm */
 	OUT_EP = 6, IN_EP = 2, MAX_BUFSIZE = 128 * 1024
 };
@@ -48,15 +45,6 @@ enum { /* pcm streaming states */
 	STREAM_STOPPING
 };
 
-enum { /* pcm sample rates (also index into RATES_XXX[]) */
-	RATE_44KHZ,
-	RATE_48KHZ,
-	RATE_88KHZ,
-	RATE_96KHZ,
-	RATE_176KHZ,
-	RATE_192KHZ
-};
-
 static const struct snd_pcm_hardware pcm_hw = {
 	.info = SNDRV_PCM_INFO_MMAP |
 		SNDRV_PCM_INFO_INTERLEAVED |
@@ -64,7 +52,7 @@ static const struct snd_pcm_hardware pcm_hw = {
 		SNDRV_PCM_INFO_MMAP_VALID |
 		SNDRV_PCM_INFO_BATCH,
 
-	.formats = SNDRV_PCM_FMTBIT_S24_LE,
+	.formats = SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S32_LE,
 
 	.rates = SNDRV_PCM_RATE_44100 |
 		SNDRV_PCM_RATE_48000 |
@@ -87,57 +75,34 @@ static const struct snd_pcm_hardware pcm_hw = {
 static int usb6fire_pcm_set_rate(struct pcm_runtime *rt)
 {
 	int ret;
-	struct usb_device *device = rt->chip->dev;
-	struct comm_runtime *comm_rt = rt->chip->comm;
+	struct control_runtime *ctrl_rt = rt->chip->control;
 
-	if (rt->rate >= ARRAY_SIZE(rates))
-		return -EINVAL;
-	/* disable streaming */
-	ret = comm_rt->write16(comm_rt, 0x02, 0x00, 0x00, 0x00);
+	ctrl_rt->usb_streaming = false;
+	ret = ctrl_rt->update_streaming(ctrl_rt);
 	if (ret < 0) {
 		snd_printk(KERN_ERR PREFIX "error stopping streaming while "
 				"setting samplerate %d.\n", rates[rt->rate]);
 		return ret;
 	}
 
-	ret = usb_set_interface(device, 1, rates_altsetting[rt->rate]);
-	if (ret < 0) {
-		snd_printk(KERN_ERR PREFIX "error setting interface "
-				"altsetting %d for samplerate %d.\n",
-				rates_altsetting[rt->rate], rates[rt->rate]);
-		return ret;
-	}
-
-	/* set soundcard clock */
-	ret = comm_rt->write16(comm_rt, 0x02, 0x01, rates_6fire_vl[rt->rate],
-			rates_6fire_vh[rt->rate]);
+	ret = ctrl_rt->set_rate(ctrl_rt, rt->rate);
 	if (ret < 0) {
 		snd_printk(KERN_ERR PREFIX "error setting samplerate %d.\n",
 				rates[rt->rate]);
 		return ret;
 	}
 
-	/* enable analog inputs and outputs
-	 * (one bit per stereo-channel) */
-	ret = comm_rt->write16(comm_rt, 0x02, 0x02,
-			(1 << (OUT_N_CHANNELS / 2)) - 1,
-			(1 << (IN_N_CHANNELS / 2)) - 1);
+	ret = ctrl_rt->set_channels(ctrl_rt, OUT_N_CHANNELS, IN_N_CHANNELS,
+			false, false);
 	if (ret < 0) {
-		snd_printk(KERN_ERR PREFIX "error initializing analog channels "
+		snd_printk(KERN_ERR PREFIX "error initializing channels "
 				"while setting samplerate %d.\n",
 				rates[rt->rate]);
 		return ret;
 	}
-	/* disable digital inputs and outputs */
-	ret = comm_rt->write16(comm_rt, 0x02, 0x03, 0x00, 0x00);
-	if (ret < 0) {
-		snd_printk(KERN_ERR PREFIX "error initializing digital "
-				"channels while setting samplerate %d.\n",
-				rates[rt->rate]);
-		return ret;
-	}
 
-	ret = comm_rt->write16(comm_rt, 0x02, 0x00, 0x00, 0x01);
+	ctrl_rt->usb_streaming = true;
+	ret = ctrl_rt->update_streaming(ctrl_rt);
 	if (ret < 0) {
 		snd_printk(KERN_ERR PREFIX "error starting streaming while "
 				"setting samplerate %d.\n", rates[rt->rate]);
@@ -168,12 +133,15 @@ static struct pcm_substream *usb6fire_pcm_get_substream(
 static void usb6fire_pcm_stream_stop(struct pcm_runtime *rt)
 {
 	int i;
+	struct control_runtime *ctrl_rt = rt->chip->control;
 
 	if (rt->stream_state != STREAM_DISABLED) {
 		for (i = 0; i < PCM_N_URBS; i++) {
 			usb_kill_urb(&rt->in_urbs[i].instance);
 			usb_kill_urb(&rt->out_urbs[i].instance);
 		}
+		ctrl_rt->usb_streaming = false;
+		ctrl_rt->update_streaming(ctrl_rt);
 		rt->stream_state = STREAM_DISABLED;
 	}
 }
@@ -228,7 +196,7 @@ static void usb6fire_pcm_capture(struct pcm_substream *sub, struct pcm_urb *urb)
 	unsigned int total_length = 0;
 	struct pcm_runtime *rt = snd_pcm_substream_chip(sub->instance);
 	struct snd_pcm_runtime *alsa_rt = sub->instance->runtime;
-	u32 *src = (u32 *) urb->buffer;
+	u32 *src = NULL;
 	u32 *dest = (u32 *) (alsa_rt->dma_area + sub->dma_off
 			* (alsa_rt->frame_bits >> 3));
 	u32 *dest_end = (u32 *) (alsa_rt->dma_area + alsa_rt->buffer_size
@@ -244,7 +212,12 @@ static void usb6fire_pcm_capture(struct pcm_substream *sub, struct pcm_urb *urb)
 		else
 			frame_count = 0;
 
-		src = (u32 *) (urb->buffer + total_length);
+		if (alsa_rt->format == SNDRV_PCM_FORMAT_S24_LE)
+			src = (u32 *) (urb->buffer + total_length);
+		else if (alsa_rt->format == SNDRV_PCM_FORMAT_S32_LE)
+			src = (u32 *) (urb->buffer - 1 + total_length);
+		else
+			return;
 		src++; /* skip leading 4 bytes of every packet */
 		total_length += urb->packets[i].length;
 		for (frame = 0; frame < frame_count; frame++) {
@@ -274,9 +247,18 @@ static void usb6fire_pcm_playback(struct pcm_substream *sub,
 			* (alsa_rt->frame_bits >> 3));
 	u32 *src_end = (u32 *) (alsa_rt->dma_area + alsa_rt->buffer_size
 			* (alsa_rt->frame_bits >> 3));
-	u32 *dest = (u32 *) urb->buffer;
+	u32 *dest;
 	int bytes_per_frame = alsa_rt->channels << 2;
 
+	if (alsa_rt->format == SNDRV_PCM_FORMAT_S32_LE)
+		dest = (u32 *) (urb->buffer - 1);
+	else if (alsa_rt->format == SNDRV_PCM_FORMAT_S24_LE)
+		dest = (u32 *) (urb->buffer);
+	else {
+		snd_printk(KERN_ERR PREFIX "Unknown sample format.");
+		return;
+	}
+
 	for (i = 0; i < PCM_N_PACKETS_PER_URB; i++) {
 		/* at least 4 header bytes for valid packet.
 		 * after that: 32 bits per sample for analog channels */
@@ -456,7 +438,7 @@ static int usb6fire_pcm_close(struct snd_pcm_substream *alsa_sub)
 		/* all substreams closed? if so, stop streaming */
 		if (!rt->playback.instance && !rt->capture.instance) {
 			usb6fire_pcm_stream_stop(rt);
-			rt->rate = -1;
+			rt->rate = ARRAY_SIZE(rates);
 		}
 	}
 	mutex_unlock(&rt->stream_mutex);
@@ -480,7 +462,6 @@ static int usb6fire_pcm_prepare(struct snd_pcm_substream *alsa_sub)
 	struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
 	struct pcm_substream *sub = usb6fire_pcm_get_substream(alsa_sub);
 	struct snd_pcm_runtime *alsa_rt = alsa_sub->runtime;
-	int i;
 	int ret;
 
 	if (rt->panic)
@@ -493,12 +474,10 @@ static int usb6fire_pcm_prepare(struct snd_pcm_substream *alsa_sub)
 	sub->period_off = 0;
 
 	if (rt->stream_state == STREAM_DISABLED) {
-		for (i = 0; i < ARRAY_SIZE(rates); i++)
-			if (alsa_rt->rate == rates[i]) {
-				rt->rate = i;
+		for (rt->rate = 0; rt->rate < ARRAY_SIZE(rates); rt->rate++)
+			if (alsa_rt->rate == rates[rt->rate])
 				break;
-			}
-		if (i == ARRAY_SIZE(rates)) {
+		if (rt->rate == ARRAY_SIZE(rates)) {
 			mutex_unlock(&rt->stream_mutex);
 			snd_printk("invalid rate %d in prepare.\n",
 					alsa_rt->rate);
@@ -613,7 +592,7 @@ int __devinit usb6fire_pcm_init(struct sfire_chip *chip)
 
 	rt->chip = chip;
 	rt->stream_state = STREAM_DISABLED;
-	rt->rate = -1;
+	rt->rate = ARRAY_SIZE(rates);
 	init_waitqueue_head(&rt->stream_wait_queue);
 	mutex_init(&rt->stream_mutex);