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

[Kieran Bingham]

From: Kieran Bingham <kieran.bing...@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.bing...@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinch...@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 --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 = {
-- 
git-series 0.9.1