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>
diff --git a/sound/usb/line6/playback.c b/sound/usb/line6/playback.c
index 97ed593..1380fac 100644
--- a/sound/usb/line6/playback.c
+++ b/sound/usb/line6/playback.c
@@ -154,10 +154,10 @@
 		(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 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 @@
 	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 @@
 	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: */