Hi Kieran,
Thank you for the patch.
On Tuesday, 27 March 2018 19:46:01 EEST Kieran Bingham wrote:
> 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@xxxxxxxxxxxxxxxx>
>
> ---
>
> v4:
> - Rebase to v4.16 (linux-media/master)
>
> drivers/media/usb/uvc/uvc_queue.c | 10 ++++------
> 1 file changed, 4 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/media/usb/uvc/uvc_queue.c
> b/drivers/media/usb/uvc/uvc_queue.c index adcc4928fae4..698d9a5a5aae 100644
> --- a/drivers/media/usb/uvc/uvc_queue.c
> +++ b/drivers/media/usb/uvc/uvc_queue.c
> @@ -169,7 +169,6 @@ 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;
> @@ -178,9 +177,9 @@ static int uvc_start_streaming(struct vb2_queue *vq,
> unsigned int count) 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 +187,13 @@ 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;
>
> 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);
> }
I think you missed my comment that stated
> Please add a one-line comment above both functions to state
>
> /* Must be called with interrupts enabled. */
Philipp Zabel commented that you could also add lockdep_assert_irqs_enabled(),
and I think that's a good idea. I'll let you decide whether to do both, or
only add lockdep_assert_irqs_enabled(), I'm fine with either option.
With this fixed,
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> static const struct vb2_ops uvc_queue_qops = {
--
Regards,
Laurent Pinchart
