This patch removes the non-required spinlock acquire/release calls on
'queue_irqlock' from 'uvc_queue_next_buffer' routine.
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.. */
static struct uvc_buffer *
uvc_queue_next_buffer(struct uvc_video_queue *queue, struct uvc_buffer *buf)
{
struct uvc_buffer *nextbuf;
- unsigned long flags;
if ((queue->flags & UVC_QUEUE_DROP_INCOMPLETE) &&
buf->buf.length != buf->buf.bytesused) {
@@ -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);
--
1.7.2.2
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