Hello. On 22-03-2012 8:50, Bhupesh Sharma wrote:
This patch removes the non-required spinlock acquire/release calls on 'queue_irqlock' from 'uvc_queue_next_buffer' routine.
'queue->irqlock' maybe?
This routine is called from 'video->encode' function (which translates to either 'uvc_video_encode_bulk' or 'uvc_video_encode_isoc') in 'uvc_video.c'. As, the 'video->encode' routines are called with 'queue_irqlock' already held, so acquiring a 'queue_irqlock' again in 'uvc_queue_next_buffer' routine causes a spin lock recursion.
Signed-off-by: Bhupesh Sharma<bhupesh.sharma@xxxxxx> Acked-by: Laurent Pinchart<laurent.pinchart@xxxxxxxxxxxxxxxx> --- drivers/usb/gadget/uvc_queue.c | 4 +--- 1 files changed, 1 insertions(+), 3 deletions(-) diff --git a/drivers/usb/gadget/uvc_queue.c b/drivers/usb/gadget/uvc_queue.c index d776adb..104ae9c 100644 --- a/drivers/usb/gadget/uvc_queue.c +++ b/drivers/usb/gadget/uvc_queue.c @@ -543,11 +543,11 @@ done: return ret; } +/* called with &queue_irqlock held.. */
'queue->irqlock' maybe?
@@ -556,14 +556,12 @@ uvc_queue_next_buffer(struct uvc_video_queue *queue, struct uvc_buffer *buf) return buf; } - spin_lock_irqsave(&queue->irqlock, flags); list_del(&buf->queue); if (!list_empty(&queue->irqqueue)) nextbuf = list_first_entry(&queue->irqqueue, struct uvc_buffer, queue); else nextbuf = NULL; - spin_unlock_irqrestore(&queue->irqlock, flags); buf->buf.sequence = queue->sequence++; do_gettimeofday(&buf->buf.timestamp);
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