Re: [PATCH v1 12/19] uvcvideo: Reorganize next buffer handling.

Laurent Pinchart
2013-11-10T23:43:13Z

Hi Pawel,

Thank you for the patch.

On Friday 30 August 2013 11:17:11 Pawel Osciak wrote:
> Move getting the first buffer from the current queue to a uvc_queue function
> and out of the USB completion handler.

Could you please add a sentence explaining why the patch is needed ?

> Signed-off-by: Pawel Osciak <posciak@chromium.org>
> ---
> drivers/media/usb/uvc/uvc_isight.c | 6 ++++--
> drivers/media/usb/uvc/uvc_queue.c | 14 ++++++++++++++
> drivers/media/usb/uvc/uvc_video.c | 29 ++++++++++++-----------------
> drivers/media/usb/uvc/uvcvideo.h | 7 +++----
> 4 files changed, 33 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/media/usb/uvc/uvc_isight.c
> b/drivers/media/usb/uvc/uvc_isight.c index 8510e72..ab01286 100644
> --- a/drivers/media/usb/uvc/uvc_isight.c
> +++ b/drivers/media/usb/uvc/uvc_isight.c
> @@ -99,10 +99,12 @@ static int isight_decode(struct uvc_video_queue *queue,
> struct uvc_buffer *buf, return 0;
> }
>
> -void uvc_video_decode_isight(struct urb *urb, struct uvc_streaming *stream,
> - struct uvc_buffer *buf)
> +void uvc_video_decode_isight(struct urb *urb, struct uvc_streaming *stream)
> {
> int ret, i;
> + struct uvc_buffer *buf;

Could you please move this on top of the previous line ?

> +
> + buf = uvc_queue_get_first_buf(&stream->queue);
>
> for (i = 0; i < urb->number_of_packets; ++i) {
> if (urb->iso_frame_desc[i].status < 0) {
> diff --git a/drivers/media/usb/uvc/uvc_queue.c
> b/drivers/media/usb/uvc/uvc_queue.c index cd962be..55d2670 100644
> --- a/drivers/media/usb/uvc/uvc_queue.c
> +++ b/drivers/media/usb/uvc/uvc_queue.c
> @@ -352,6 +352,20 @@ void uvc_queue_cancel(struct uvc_video_queue *queue,
> int disconnect) spin_unlock_irqrestore(&queue->irqlock, flags);
> }
>
> +struct uvc_buffer *uvc_queue_get_first_buf(struct uvc_video_queue *queue)
> +{
> + struct uvc_buffer *buf = NULL;
> + unsigned long flags;
> +
> + spin_lock_irqsave(&queue->irqlock, flags);
> + if (!list_empty(&queue->irqqueue))
> + buf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
> + queue);
> + spin_unlock_irqrestore(&queue->irqlock, flags);
> +
> + return buf;
> +}
> +
> struct uvc_buffer *uvc_queue_next_buffer(struct uvc_video_queue *queue,
> struct uvc_buffer *buf)
> {
> diff --git a/drivers/media/usb/uvc/uvc_video.c
> b/drivers/media/usb/uvc/uvc_video.c index b4ebccd..2f9a5fa 100644
> --- a/drivers/media/usb/uvc/uvc_video.c
> +++ b/drivers/media/usb/uvc/uvc_video.c
> @@ -1193,11 +1193,11 @@ static int uvc_video_encode_data(struct
> uvc_streaming *stream, /*
> * Completion handler for video URBs.
> */
> -static void uvc_video_decode_isoc(struct urb *urb, struct uvc_streaming
> *stream, - struct uvc_buffer *buf)
> +static void uvc_video_decode_isoc(struct urb *urb, struct uvc_streaming
> *stream) {
> u8 *mem;
> int ret, i;
> + struct uvc_buffer *buf = NULL;

Same here (and below).

> for (i = 0; i < urb->number_of_packets; ++i) {
> if (urb->iso_frame_desc[i].status < 0) {
> @@ -1211,6 +1211,7 @@ static void uvc_video_decode_isoc(struct urb *urb,
> struct uvc_streaming *stream,
>
> /* Decode the payload header. */
> mem = urb->transfer_buffer + urb->iso_frame_desc[i].offset;
> + buf = uvc_queue_get_first_buf(&stream->queue);

Can't this call be moved outside of the loop ?

> do {
> ret = uvc_video_decode_start(stream, buf, mem,
> urb->iso_frame_desc[i].actual_length);
> @@ -1241,11 +1242,11 @@ static void uvc_video_decode_isoc(struct urb *urb,
> struct uvc_streaming *stream, }
> }
>
> -static void uvc_video_decode_bulk(struct urb *urb, struct uvc_streaming
> *stream, - struct uvc_buffer *buf)
> +static void uvc_video_decode_bulk(struct urb *urb, struct uvc_streaming
> *stream) {
> u8 *mem;
> int len, ret;
> + struct uvc_buffer *buf;
>
> /*
> * Ignore ZLPs if they're not part of a frame, otherwise process them
> @@ -1258,6 +1259,8 @@ static void uvc_video_decode_bulk(struct urb *urb,
> struct uvc_streaming *stream, len = urb->actual_length;
> stream->bulk.payload_size += len;
>
> + buf = uvc_queue_get_first_buf(&stream->queue);
> +
> /* If the URB is the first of its payload, decode and save the
> * header.
> */
> @@ -1309,12 +1312,13 @@ static void uvc_video_decode_bulk(struct urb *urb,
> struct uvc_streaming *stream, }
> }
>
> -static void uvc_video_encode_bulk(struct urb *urb, struct uvc_streaming
> *stream, - struct uvc_buffer *buf)
> +static void uvc_video_encode_bulk(struct urb *urb, struct uvc_streaming
> *stream) {
> u8 *mem = urb->transfer_buffer;
> int len = stream->urb_size, ret;
> + struct uvc_buffer *buf;
>
> + buf = uvc_queue_get_first_buf(&stream->queue);
> if (buf == NULL) {
> urb->transfer_buffer_length = 0;
> return;
> @@ -1355,9 +1359,6 @@ static void uvc_video_encode_bulk(struct urb *urb,
> struct uvc_streaming *stream, static void uvc_video_complete(struct urb
> *urb)
> {
> struct uvc_streaming *stream = urb->context;
> - struct uvc_video_queue *queue = &stream->queue;
> - struct uvc_buffer *buf = NULL;
> - unsigned long flags;
> int ret;
>
> switch (urb->status) {
> @@ -1374,17 +1375,11 @@ static void uvc_video_complete(struct urb *urb)
>
> case -ECONNRESET: /* usb_unlink_urb() called. */
> case -ESHUTDOWN: /* The endpoint is being disabled. */
> - uvc_queue_cancel(queue, urb->status == -ESHUTDOWN);
> + uvc_queue_cancel(&stream->queue, urb->status == -ESHUTDOWN);
> return;
> }
>
> - spin_lock_irqsave(&queue->irqlock, flags);
> - if (!list_empty(&queue->irqqueue))
> - buf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
> - queue);
> - spin_unlock_irqrestore(&queue->irqlock, flags);
> -
> - stream->decode(urb, stream, buf);
> + stream->decode(urb, stream);
>
> if ((ret = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
> uvc_printk(KERN_ERR, "Failed to resubmit video URB (%d).\n",
> diff --git a/drivers/media/usb/uvc/uvcvideo.h
> b/drivers/media/usb/uvc/uvcvideo.h index 46ffd92..bca8715 100644
> --- a/drivers/media/usb/uvc/uvcvideo.h
> +++ b/drivers/media/usb/uvc/uvcvideo.h
> @@ -482,8 +482,7 @@ struct uvc_streaming {
> /* Buffers queue. */
> unsigned int frozen : 1;
> struct uvc_video_queue queue;
> - void (*decode) (struct urb *urb, struct uvc_streaming *video,
> - struct uvc_buffer *buf);
> + void (*decode) (struct urb *urb, struct uvc_streaming *video);
>
> /* Context data used by the bulk completion handler. */
> struct {
> @@ -659,6 +658,7 @@ extern int uvc_dequeue_buffer(struct uvc_video_queue
> *queue, struct v4l2_buffer *v4l2_buf, int nonblocking);
> extern int uvc_queue_enable(struct uvc_video_queue *queue, int enable);
> extern void uvc_queue_cancel(struct uvc_video_queue *queue, int
> disconnect); +struct uvc_buffer *uvc_queue_get_first_buf(struct
> uvc_video_queue *queue); extern struct uvc_buffer
> *uvc_queue_next_buffer(struct uvc_video_queue *queue, struct uvc_buffer
> *buf);
> extern int uvc_queue_mmap(struct uvc_video_queue *queue,
> @@ -751,8 +751,7 @@ extern struct usb_host_endpoint *uvc_find_endpoint(
> struct usb_host_interface *alts, __u8 epaddr);
>
> /* Quirks support */
> -void uvc_video_decode_isight(struct urb *urb, struct uvc_streaming *stream,
> - struct uvc_buffer *buf);
> +void uvc_video_decode_isight(struct urb *urb, struct uvc_streaming
> *stream);
>
> /* debugfs and statistics */
> int uvc_debugfs_init(void);
--
Regards,

Laurent Pinchart