diff mbox series

[v5,4/9] media: uvcvideo: queue: Simplify spin-lock usage

Message ID 210be9b2f38af75b3747415d0372f4f12b2bee19.1541534872.git-series.kieran.bingham@ideasonboard.com (mailing list archive)
State New, archived
Headers show
Series Asynchronous UVC | expand

Commit Message

Kieran Bingham Nov. 6, 2018, 9:27 p.m. UTC 
From: Kieran Bingham <kieran.bingham@ideasonboard.com>

Both uvc_start_streaming(), and uvc_stop_streaming() are called from
userspace context, with interrupts enabled. As such, they do not need to
save the IRQ state, and can use spin_lock_irq() and spin_unlock_irq()
respectively.

Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

---

v4:
 - Rebase to v4.16 (linux-media/master)

v5:
 - Provide lockdep validation

 drivers/media/usb/uvc/uvc_queue.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)
diff mbox series

Patch

diff --git a/drivers/media/usb/uvc/uvc_queue.c b/drivers/media/usb/uvc/uvc_queue.c
index 74f9483911d0..bebf2415d9de 100644
--- a/drivers/media/usb/uvc/uvc_queue.c
+++ b/drivers/media/usb/uvc/uvc_queue.c
@@ -169,18 +169,19 @@  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;
 
+	lockdep_assert_irqs_enabled();
+
 	queue->buf_used = 0;
 
 	ret = uvc_video_enable(stream, 1);
 	if (ret == 0)
 		return 0;
 
-	spin_lock_irqsave(&queue->irqlock, flags);
+	spin_lock_irq(&queue->irqlock);
 	uvc_queue_return_buffers(queue, UVC_BUF_STATE_QUEUED);
-	spin_unlock_irqrestore(&queue->irqlock, flags);
+	spin_unlock_irq(&queue->irqlock);
 
 	return ret;
 }
@@ -188,14 +189,15 @@  static int uvc_start_streaming(struct vb2_queue *vq, unsigned int count)
 static void uvc_stop_streaming(struct vb2_queue *vq)
 {
 	struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
-	unsigned long flags;
+
+	lockdep_assert_irqs_enabled();
 
 	if (vq->type != V4L2_BUF_TYPE_META_CAPTURE)
 		uvc_video_enable(uvc_queue_to_stream(queue), 0);
 
-	spin_lock_irqsave(&queue->irqlock, flags);
+	spin_lock_irq(&queue->irqlock);
 	uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR);
-	spin_unlock_irqrestore(&queue->irqlock, flags);
+	spin_unlock_irq(&queue->irqlock);
 }
 
 static const struct vb2_ops uvc_queue_qops = {