media: uvcvideo: Utilise for_each_uvc_urb iterator

A new iterator is available for processing UVC URB structures. This
simplifies the processing of the internal stream data.

Convert the manual loop iterators to the new helper, adding an index
helper to keep the existing debug print.

Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

2 files changed, 24 insertions, 25 deletions

diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
index f9019546645f..84525ff04745 100644
--- a/drivers/media/usb/uvc/uvc_video.c
+++ b/drivers/media/usb/uvc/uvc_video.c
@@ -1556,20 +1556,19 @@ static void uvc_video_complete(struct urb *urb)
  */
 static void uvc_free_urb_buffers(struct uvc_streaming *stream)
 {
-	unsigned int i;
+	struct uvc_urb *uvc_urb;
 
-	for (i = 0; i < UVC_URBS; ++i) {
-		struct uvc_urb *uvc_urb = &stream->uvc_urb[i];
+	for_each_uvc_urb(uvc_urb, stream) {
+		if (!uvc_urb->buffer)
+			continue;
 
-		if (uvc_urb->buffer) {
 #ifndef CONFIG_DMA_NONCOHERENT
-			usb_free_coherent(stream->dev->udev, stream->urb_size,
-					uvc_urb->buffer, uvc_urb->dma);
+		usb_free_coherent(stream->dev->udev, stream->urb_size,
+				  uvc_urb->buffer, uvc_urb->dma);
 #else
-			kfree(uvc_urb->buffer);
+		kfree(uvc_urb->buffer);
 #endif
-			uvc_urb->buffer = NULL;
-		}
+		uvc_urb->buffer = NULL;
 	}
 
 	stream->urb_size = 0;
@@ -1701,7 +1700,8 @@ static int uvc_init_video_isoc(struct uvc_streaming *stream,
 	struct usb_host_endpoint *ep, gfp_t gfp_flags)
 {
 	struct urb *urb;
-	unsigned int npackets, i, j;
+	struct uvc_urb *uvc_urb;
+	unsigned int npackets, i;
 	u16 psize;
 	u32 size;
 
@@ -1714,9 +1714,7 @@ static int uvc_init_video_isoc(struct uvc_streaming *stream,
 
 	size = npackets * psize;
 
-	for (i = 0; i < UVC_URBS; ++i) {
-		struct uvc_urb *uvc_urb = &stream->uvc_urb[i];
-
+	for_each_uvc_urb(uvc_urb, stream) {
 		urb = usb_alloc_urb(npackets, gfp_flags);
 		if (urb == NULL) {
 			uvc_video_stop_transfer(stream, 1);
@@ -1739,9 +1737,9 @@ static int uvc_init_video_isoc(struct uvc_streaming *stream,
 		urb->number_of_packets = npackets;
 		urb->transfer_buffer_length = size;
 
-		for (j = 0; j < npackets; ++j) {
-			urb->iso_frame_desc[j].offset = j * psize;
-			urb->iso_frame_desc[j].length = psize;
+		for (i = 0; i < npackets; ++i) {
+			urb->iso_frame_desc[i].offset = i * psize;
+			urb->iso_frame_desc[i].length = psize;
 		}
 
 		uvc_urb->urb = urb;
@@ -1758,7 +1756,8 @@ static int uvc_init_video_bulk(struct uvc_streaming *stream,
 	struct usb_host_endpoint *ep, gfp_t gfp_flags)
 {
 	struct urb *urb;
-	unsigned int npackets, pipe, i;
+	struct uvc_urb *uvc_urb;
+	unsigned int npackets, pipe;
 	u16 psize;
 	u32 size;
 
@@ -1782,9 +1781,7 @@ static int uvc_init_video_bulk(struct uvc_streaming *stream,
 	if (stream->type == V4L2_BUF_TYPE_VIDEO_OUTPUT)
 		size = 0;
 
-	for (i = 0; i < UVC_URBS; ++i) {
-		struct uvc_urb *uvc_urb = &stream->uvc_urb[i];
-
+	for_each_uvc_urb(uvc_urb, stream) {
 		urb = usb_alloc_urb(0, gfp_flags);
 		if (urb == NULL) {
 			uvc_video_stop_transfer(stream, 1);
@@ -1812,6 +1809,7 @@ static int uvc_video_start_transfer(struct uvc_streaming *stream,
 {
 	struct usb_interface *intf = stream->intf;
 	struct usb_host_endpoint *ep;
+	struct uvc_urb *uvc_urb;
 	unsigned int i;
 	int ret;
 
@@ -1889,13 +1887,11 @@ static int uvc_video_start_transfer(struct uvc_streaming *stream,
 		return ret;
 
 	/* Submit the URBs. */
-	for (i = 0; i < UVC_URBS; ++i) {
-		struct uvc_urb *uvc_urb = &stream->uvc_urb[i];
-
+	for_each_uvc_urb(uvc_urb, stream) {
 		ret = usb_submit_urb(uvc_urb->urb, gfp_flags);
 		if (ret < 0) {
-			uvc_printk(KERN_ERR, "Failed to submit URB %u "
-					"(%d).\n", i, ret);
+			uvc_printk(KERN_ERR, "Failed to submit URB %u (%d).\n",
+				   uvc_urb_index(uvc_urb), ret);
 			uvc_video_stop_transfer(stream, 1);
 			return ret;
 		}
diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index 74fd6c27d64d..9b41b14ce076 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -620,6 +620,9 @@ struct uvc_streaming {
 	     (uvc_urb) < &(uvc_streaming)->uvc_urb[UVC_URBS]; \
 	     ++(uvc_urb))
 
+#define uvc_urb_index(uvc_urb) \
+	(unsigned int)((uvc_urb) - (&(uvc_urb)->stream->uvc_urb[0]))
+
 struct uvc_device_info {
 	u32	quirks;
 	u32	meta_format;