ALSA: line6: Enable different number of URBs for frame transfers

This basically changes LINE6_ISO_BUFFERS constant to a configurable
iso_buffers property.
Signed-off-by: Andrej Krutak <dev@andree.sk>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/usb/line6/capture.c

@@ -29,10 +29,10 @@ static int submit_audio_in_urb(struct snd_line6_pcm *line6pcm)
 	int ret;
 	struct urb *urb_in;
 
-	index =
-	    find_first_zero_bit(&line6pcm->in.active_urbs, LINE6_ISO_BUFFERS);
+	index = find_first_zero_bit(&line6pcm->in.active_urbs,
+				    line6pcm->line6->iso_buffers);
 
-	if (index < 0 || index >= LINE6_ISO_BUFFERS) {
+	if (index < 0 || index >= line6pcm->line6->iso_buffers) {
 		dev_err(line6pcm->line6->ifcdev, "no free URB found\n");
 		return -EINVAL;
 	}
@@ -73,7 +73,7 @@ int line6_submit_audio_in_all_urbs(struct snd_line6_pcm *line6pcm)
 {
 	int ret = 0, i;
 
-	for (i = 0; i < LINE6_ISO_BUFFERS; ++i) {
+	for (i = 0; i < line6pcm->line6->iso_buffers; ++i) {
 		ret = submit_audio_in_urb(line6pcm);
 		if (ret < 0)
 			break;
@@ -154,7 +154,7 @@ static void audio_in_callback(struct urb *urb)
 	line6pcm->in.last_frame = urb->start_frame;
 
 	/* find index of URB */
-	for (index = 0; index < LINE6_ISO_BUFFERS; ++index)
+	for (index = 0; index < line6pcm->line6->iso_buffers; ++index)
 		if (urb == line6pcm->in.urbs[index])
 			break;
 
@@ -247,8 +247,13 @@ int line6_create_audio_in_urbs(struct snd_line6_pcm *line6pcm)
 	struct usb_line6 *line6 = line6pcm->line6;
 	int i;
 
+	line6pcm->in.urbs = kzalloc(
+		sizeof(struct urb *) * line6->iso_buffers, GFP_KERNEL);
+	if (line6pcm->in.urbs == NULL)
+		return -ENOMEM;
+
 	/* create audio URBs and fill in constant values: */
-	for (i = 0; i < LINE6_ISO_BUFFERS; ++i) {
+	for (i = 0; i < line6->iso_buffers; ++i) {
 		struct urb *urb;
 
 		/* URB for audio in: */

sound/usb/line6/driver.c

@@ -467,6 +467,7 @@ static void line6_get_interval(struct usb_line6 *line6)
 	unsigned epnum = usb_pipeendpoint(pipe);
 
 	ep = usbdev->ep_in[epnum];
+	line6->iso_buffers = LINE6_ISO_BUFFERS;
 	if (ep) {
 		line6->interval = ep->desc.bInterval;
 		line6->max_packet_size = le16_to_cpu(ep->desc.wMaxPacketSize);

sound/usb/line6/driver.h

@@ -111,6 +111,8 @@ struct usb_line6 {
 
 	/* Interval (ms) */
 	int interval;
+	/* Number of isochronous URBs used for frame transfers */
+	int iso_buffers;
 
 	/* Maximum size of USB packet */
 	int max_packet_size;

sound/usb/line6/pcm.c

@@ -104,7 +104,7 @@ static void line6_unlink_audio_urbs(struct snd_line6_pcm *line6pcm,
 {
 	int i;
 
-	for (i = 0; i < LINE6_ISO_BUFFERS; i++) {
+	for (i = 0; i < line6pcm->line6->iso_buffers; i++) {
 		if (test_bit(i, &pcms->active_urbs)) {
 			if (!test_and_set_bit(i, &pcms->unlink_urbs))
 				usb_unlink_urb(pcms->urbs[i]);
@@ -124,7 +124,7 @@ static void line6_wait_clear_audio_urbs(struct snd_line6_pcm *line6pcm,
 
 	do {
 		alive = 0;
-		for (i = 0; i < LINE6_ISO_BUFFERS; i++) {
+		for (i = 0; i < line6pcm->line6->iso_buffers; i++) {
 			if (test_bit(i, &pcms->active_urbs))
 				alive++;
 		}
@@ -153,7 +153,8 @@ static int line6_buffer_acquire(struct snd_line6_pcm *line6pcm,
 {
 	/* Invoked multiple times in a row so allocate once only */
 	if (!test_and_set_bit(type, &pstr->opened) && !pstr->buffer) {
-		pstr->buffer = kmalloc(LINE6_ISO_BUFFERS * LINE6_ISO_PACKETS *
+		pstr->buffer = kmalloc(line6pcm->line6->iso_buffers *
+				       LINE6_ISO_PACKETS *
 				       line6pcm->max_packet_size, GFP_KERNEL);
 		if (!pstr->buffer)
 			return -ENOMEM;
@@ -434,24 +435,30 @@ static struct snd_kcontrol_new line6_controls[] = {
 /*
 	Cleanup the PCM device.
 */
-static void cleanup_urbs(struct line6_pcm_stream *pcms)
+static void cleanup_urbs(struct line6_pcm_stream *pcms, int iso_buffers)
 {
 	int i;
 
-	for (i = 0; i < LINE6_ISO_BUFFERS; i++) {
+	/* Most likely impossible in current code... */
+	if (pcms->urbs == NULL)
+		return;
+
+	for (i = 0; i < iso_buffers; i++) {
 		if (pcms->urbs[i]) {
 			usb_kill_urb(pcms->urbs[i]);
 			usb_free_urb(pcms->urbs[i]);
 		}
 	}
+	kfree(pcms->urbs);
+	pcms->urbs = NULL;
 }
 
 static void line6_cleanup_pcm(struct snd_pcm *pcm)
 {
 	struct snd_line6_pcm *line6pcm = snd_pcm_chip(pcm);
 
-	cleanup_urbs(&line6pcm->out);
-	cleanup_urbs(&line6pcm->in);
+	cleanup_urbs(&line6pcm->out, line6pcm->line6->iso_buffers);
+	cleanup_urbs(&line6pcm->in, line6pcm->line6->iso_buffers);
 	kfree(line6pcm);
 }
 

sound/usb/line6/pcm.h

@@ -90,7 +90,7 @@ struct line6_pcm_properties {
 
 struct line6_pcm_stream {
 	/* allocated URBs */
-	struct urb *urbs[LINE6_ISO_BUFFERS];
+	struct urb **urbs;
 
 	/* Temporary buffer;
 	 * Since the packet size is not known in advance, this buffer is

sound/usb/line6/playback.c

@@ -154,10 +154,10 @@ static int submit_audio_out_urb(struct snd_line6_pcm *line6pcm)
 		(USB_INTERVALS_PER_SECOND / LINE6_ISO_INTERVAL);
 	struct urb *urb_out;
 
-	index =
-	    find_first_zero_bit(&line6pcm->out.active_urbs, LINE6_ISO_BUFFERS);
+	index = find_first_zero_bit(&line6pcm->out.active_urbs,
+				    line6pcm->line6->iso_buffers);
 
-	if (index < 0 || index >= LINE6_ISO_BUFFERS) {
+	if (index < 0 || index >= line6pcm->line6->iso_buffers) {
 		dev_err(line6pcm->line6->ifcdev, "no free URB found\n");
 		return -EINVAL;
 	}
@@ -286,7 +286,7 @@ int line6_submit_audio_out_all_urbs(struct snd_line6_pcm *line6pcm)
 {
 	int ret = 0, i;
 
-	for (i = 0; i < LINE6_ISO_BUFFERS; ++i) {
+	for (i = 0; i < line6pcm->line6->iso_buffers; ++i) {
 		ret = submit_audio_out_urb(line6pcm);
 		if (ret < 0)
 			break;
@@ -313,11 +313,11 @@ static void audio_out_callback(struct urb *urb)
 	line6pcm->out.last_frame = urb->start_frame;
 
 	/* find index of URB */
-	for (index = 0; index < LINE6_ISO_BUFFERS; index++)
+	for (index = 0; index < line6pcm->line6->iso_buffers; index++)
 		if (urb == line6pcm->out.urbs[index])
 			break;
 
-	if (index >= LINE6_ISO_BUFFERS)
+	if (index >= line6pcm->line6->iso_buffers)
 		return;		/* URB has been unlinked asynchronously */
 
 	for (i = 0; i < LINE6_ISO_PACKETS; i++)
@@ -401,8 +401,13 @@ int line6_create_audio_out_urbs(struct snd_line6_pcm *line6pcm)
 	struct usb_line6 *line6 = line6pcm->line6;
 	int i;
 
+	line6pcm->out.urbs = kzalloc(
+		sizeof(struct urb *) * line6->iso_buffers, GFP_KERNEL);
+	if (line6pcm->out.urbs == NULL)
+		return -ENOMEM;
+
 	/* create audio URBs and fill in constant values: */
-	for (i = 0; i < LINE6_ISO_BUFFERS; ++i) {
+	for (i = 0; i < line6->iso_buffers; ++i) {
 		struct urb *urb;
 
 		/* URB for audio out: */