1 files changed, 29 insertions, 18 deletions

diff --git a/drivers/media/video/uvc/uvc_video.c b/drivers/media/video/uvc/uvc_video.c
index 05139a4f14f..7dcf534a0cf 100644
--- a/drivers/media/video/uvc/uvc_video.c
+++ b/drivers/media/video/uvc/uvc_video.c
@@ -145,7 +145,7 @@ static int uvc_get_video_ctrl(struct uvc_streaming *stream,
 		uvc_warn_once(stream->dev, UVC_WARN_MINMAX, "UVC non "
 			"compliance - GET_MIN/MAX(PROBE) incorrectly "
 			"supported. Enabling workaround.\n");
-		memset(ctrl, 0, sizeof ctrl);
+		memset(ctrl, 0, sizeof *ctrl);
 		ctrl->wCompQuality = le16_to_cpup((__le16 *)data);
 		ret = 0;
 		goto out;
@@ -441,7 +441,7 @@ static int uvc_video_decode_start(struct uvc_streaming *stream,
 	if (fid != stream->last_fid && buf->buf.bytesused != 0) {
 		uvc_trace(UVC_TRACE_FRAME, "Frame complete (FID bit "
 				"toggled).\n");
-		buf->state = UVC_BUF_STATE_DONE;
+		buf->state = UVC_BUF_STATE_READY;
 		return -EAGAIN;
 	}
 
@@ -470,7 +470,7 @@ static void uvc_video_decode_data(struct uvc_streaming *stream,
 	/* Complete the current frame if the buffer size was exceeded. */
 	if (len > maxlen) {
 		uvc_trace(UVC_TRACE_FRAME, "Frame complete (overflow).\n");
-		buf->state = UVC_BUF_STATE_DONE;
+		buf->state = UVC_BUF_STATE_READY;
 	}
 }
 
@@ -482,7 +482,7 @@ static void uvc_video_decode_end(struct uvc_streaming *stream,
 		uvc_trace(UVC_TRACE_FRAME, "Frame complete (EOF found).\n");
 		if (data[0] == len)
 			uvc_trace(UVC_TRACE_FRAME, "EOF in empty payload.\n");
-		buf->state = UVC_BUF_STATE_DONE;
+		buf->state = UVC_BUF_STATE_READY;
 		if (stream->dev->quirks & UVC_QUIRK_STREAM_NO_FID)
 			stream->last_fid ^= UVC_STREAM_FID;
 	}
@@ -568,8 +568,7 @@ static void uvc_video_decode_isoc(struct urb *urb, struct uvc_streaming *stream,
 		uvc_video_decode_end(stream, buf, mem,
 			urb->iso_frame_desc[i].actual_length);
 
-		if (buf->state == UVC_BUF_STATE_DONE ||
-		    buf->state == UVC_BUF_STATE_ERROR)
+		if (buf->state == UVC_BUF_STATE_READY)
 			buf = uvc_queue_next_buffer(&stream->queue, buf);
 	}
 }
@@ -627,8 +626,7 @@ static void uvc_video_decode_bulk(struct urb *urb, struct uvc_streaming *stream,
 		if (!stream->bulk.skip_payload && buf != NULL) {
 			uvc_video_decode_end(stream, buf, stream->bulk.header,
 				stream->bulk.payload_size);
-			if (buf->state == UVC_BUF_STATE_DONE ||
-			    buf->state == UVC_BUF_STATE_ERROR)
+			if (buf->state == UVC_BUF_STATE_READY)
 				buf = uvc_queue_next_buffer(&stream->queue,
 							    buf);
 		}
@@ -669,7 +667,7 @@ static void uvc_video_encode_bulk(struct urb *urb, struct uvc_streaming *stream,
 	    stream->bulk.payload_size == stream->bulk.max_payload_size) {
 		if (buf->buf.bytesused == stream->queue.buf_used) {
 			stream->queue.buf_used = 0;
-			buf->state = UVC_BUF_STATE_DONE;
+			buf->state = UVC_BUF_STATE_READY;
 			uvc_queue_next_buffer(&stream->queue, buf);
 			stream->last_fid ^= UVC_STREAM_FID;
 		}
@@ -924,10 +922,8 @@ static int uvc_init_video_bulk(struct uvc_streaming *stream,
 static int uvc_init_video(struct uvc_streaming *stream, gfp_t gfp_flags)
 {
 	struct usb_interface *intf = stream->intf;
-	struct usb_host_interface *alts;
-	struct usb_host_endpoint *ep = NULL;
-	int intfnum = stream->intfnum;
-	unsigned int bandwidth, psize, i;
+	struct usb_host_endpoint *ep;
+	unsigned int i;
 	int ret;
 
 	stream->last_fid = -1;
@@ -936,6 +932,12 @@ static int uvc_init_video(struct uvc_streaming *stream, gfp_t gfp_flags)
 	stream->bulk.payload_size = 0;
 
 	if (intf->num_altsetting > 1) {
+		struct usb_host_endpoint *best_ep = NULL;
+		unsigned int best_psize = 3 * 1024;
+		unsigned int bandwidth;
+		unsigned int uninitialized_var(altsetting);
+		int intfnum = stream->intfnum;
+
 		/* Isochronous endpoint, select the alternate setting. */
 		bandwidth = stream->ctrl.dwMaxPayloadTransferSize;
 
@@ -949,6 +951,9 @@ static int uvc_init_video(struct uvc_streaming *stream, gfp_t gfp_flags)
 		}
 
 		for (i = 0; i < intf->num_altsetting; ++i) {
+			struct usb_host_interface *alts;
+			unsigned int psize;
+
 			alts = &intf->altsetting[i];
 			ep = uvc_find_endpoint(alts,
 				stream->header.bEndpointAddress);
@@ -958,21 +963,27 @@ static int uvc_init_video(struct uvc_streaming *stream, gfp_t gfp_flags)
 			/* Check if the bandwidth is high enough. */
 			psize = le16_to_cpu(ep->desc.wMaxPacketSize);
 			psize = (psize & 0x07ff) * (1 + ((psize >> 11) & 3));
-			if (psize >= bandwidth)
-				break;
+			if (psize >= bandwidth && psize <= best_psize) {
+				altsetting = i;
+				best_psize = psize;
+				best_ep = ep;
+			}
 		}
 
-		if (i >= intf->num_altsetting) {
+		if (best_ep == NULL) {
 			uvc_trace(UVC_TRACE_VIDEO, "No fast enough alt setting "
 				"for requested bandwidth.\n");
 			return -EIO;
 		}
 
-		ret = usb_set_interface(stream->dev->udev, intfnum, i);
+		uvc_trace(UVC_TRACE_VIDEO, "Selecting alternate setting %u "
+			"(%u B/frame bandwidth).\n", altsetting, best_psize);
+
+		ret = usb_set_interface(stream->dev->udev, intfnum, altsetting);
 		if (ret < 0)
 			return ret;
 
-		ret = uvc_init_video_isoc(stream, ep, gfp_flags);
+		ret = uvc_init_video_isoc(stream, best_ep, gfp_flags);
 	} else {
 		/* Bulk endpoint, proceed to URB initialization. */
 		ep = uvc_find_endpoint(&intf->altsetting[0],