From 6190c79df861d2c78a7448fe6d4260e5fa53b9b9 Mon Sep 17 00:00:00 2001 From: Bhupesh Sharma Date: Fri, 23 Mar 2012 22:23:13 +0530 Subject: [PATCH] usb: gadget: uvc: Remove non-required locking from 'uvc_queue_next_buffer' routine 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 Acked-by: Laurent Pinchart Signed-off-by: Felipe Balbi --- drivers/usb/gadget/uvc_queue.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/usb/gadget/uvc_queue.c b/drivers/usb/gadget/uvc_queue.c index d776adb2da67..0cdf89d32a15 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); -- 2.11.0