From ef33d901db3026643f1c415562d633dfc6c5e9bb Mon Sep 17 00:00:00 2001 From: Laurent Pinchart Date: Tue, 21 Oct 2014 16:37:55 -0300 Subject: [PATCH] [media] uvcvideo: Return all buffers to vb2 at stream stop and start failure videobuf2 requires drivers to give back ownership of all queue buffers in the stop_streaming operation, as well as in the start_streaming operation in case of failure. Mark all queued buffers as done in the error or queued state. Signed-off-by: Laurent Pinchart Signed-off-by: Mauro Carvalho Chehab --- drivers/media/usb/uvc/uvc_queue.c | 45 ++++++++++++++++++++++++------- 1 file changed, 35 insertions(+), 10 deletions(-) diff --git a/drivers/media/usb/uvc/uvc_queue.c b/drivers/media/usb/uvc/uvc_queue.c index c295c5c719c8..cc960723b926 100644 --- a/drivers/media/usb/uvc/uvc_queue.c +++ b/drivers/media/usb/uvc/uvc_queue.c @@ -42,6 +42,28 @@ uvc_queue_to_stream(struct uvc_video_queue *queue) return container_of(queue, struct uvc_streaming, queue); } +/* + * Return all queued buffers to videobuf2 in the requested state. + * + * This function must be called with the queue spinlock held. + */ +static void uvc_queue_return_buffers(struct uvc_video_queue *queue, + enum uvc_buffer_state state) +{ + enum vb2_buffer_state vb2_state = state == UVC_BUF_STATE_ERROR + ? VB2_BUF_STATE_ERROR + : VB2_BUF_STATE_QUEUED; + + while (!list_empty(&queue->irqqueue)) { + struct uvc_buffer *buf = list_first_entry(&queue->irqqueue, + struct uvc_buffer, + queue); + list_del(&buf->queue); + buf->state = state; + vb2_buffer_done(&buf->buf, vb2_state); + } +} + /* ----------------------------------------------------------------------------- * videobuf2 queue operations */ @@ -139,10 +161,20 @@ static int uvc_start_streaming(struct vb2_queue *vq, unsigned int count) { struct uvc_video_queue *queue = vb2_get_drv_priv(vq); struct uvc_streaming *stream = uvc_queue_to_stream(queue); + unsigned long flags; + int ret; queue->buf_used = 0; - return uvc_video_enable(stream, 1); + ret = uvc_video_enable(stream, 1); + if (ret == 0) + return 0; + + spin_lock_irqsave(&queue->irqlock, flags); + uvc_queue_return_buffers(queue, UVC_BUF_STATE_QUEUED); + spin_unlock_irqrestore(&queue->irqlock, flags); + + return ret; } static void uvc_stop_streaming(struct vb2_queue *vq) @@ -154,7 +186,7 @@ static void uvc_stop_streaming(struct vb2_queue *vq) uvc_video_enable(stream, 0); spin_lock_irqsave(&queue->irqlock, flags); - INIT_LIST_HEAD(&queue->irqqueue); + uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR); spin_unlock_irqrestore(&queue->irqlock, flags); } @@ -353,17 +385,10 @@ int uvc_queue_allocated(struct uvc_video_queue *queue) */ void uvc_queue_cancel(struct uvc_video_queue *queue, int disconnect) { - struct uvc_buffer *buf; unsigned long flags; spin_lock_irqsave(&queue->irqlock, flags); - while (!list_empty(&queue->irqqueue)) { - buf = list_first_entry(&queue->irqqueue, struct uvc_buffer, - queue); - list_del(&buf->queue); - buf->state = UVC_BUF_STATE_ERROR; - vb2_buffer_done(&buf->buf, VB2_BUF_STATE_ERROR); - } + uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR); /* This must be protected by the irqlock spinlock to avoid race * conditions between uvc_buffer_queue and the disconnection event that * could result in an interruptible wait in uvc_dequeue_buffer. Do not -- 2.20.1