[media] vb2: stop_streaming should return void

The vb2 core ignores any return code from the stop_streaming op.
And there really isn't anything it can do anyway in case of an error.
So change the return type to void and update any drivers that implement it.

The int return gave drivers the idea that this operation could actually
fail, but that's really not the case.

The pwc amd sdr-msi3101 drivers both had this construction:

        if (mutex_lock_interruptible(&s->v4l2_lock))
                return -ERESTARTSYS;

This has been updated to just call mutex_lock(). The stop_streaming op
expects this to really stop streaming and I very much doubt this will
work reliably if stop_streaming just returns without really stopping the
DMA.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Pawel Osciak <pawel@osciak.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

6 files changed, 12 insertions, 23 deletions

diff --git a/drivers/media/usb/em28xx/em28xx-v4l.h b/drivers/media/usb/em28xx/em28xx-v4l.h
index bce438691e0e..432862c20bbf 100644
--- a/drivers/media/usb/em28xx/em28xx-v4l.h
+++ b/drivers/media/usb/em28xx/em28xx-v4l.h
@@ -16,5 +16,5 @@
 
 
 int em28xx_start_analog_streaming(struct vb2_queue *vq, unsigned int count);
-int em28xx_stop_vbi_streaming(struct vb2_queue *vq);
+void em28xx_stop_vbi_streaming(struct vb2_queue *vq);
 extern struct vb2_ops em28xx_vbi_qops;
diff --git a/drivers/media/usb/em28xx/em28xx-video.c b/drivers/media/usb/em28xx/em28xx-video.c
index 0856e5d367b6..cdcd7513e6ec 100644
--- a/drivers/media/usb/em28xx/em28xx-video.c
+++ b/drivers/media/usb/em28xx/em28xx-video.c
@@ -937,7 +937,7 @@ int em28xx_start_analog_streaming(struct vb2_queue *vq, unsigned int count)
 	return rc;
 }
 
-static int em28xx_stop_streaming(struct vb2_queue *vq)
+static void em28xx_stop_streaming(struct vb2_queue *vq)
 {
 	struct em28xx *dev = vb2_get_drv_priv(vq);
 	struct em28xx_dmaqueue *vidq = &dev->vidq;
@@ -961,11 +961,9 @@ static int em28xx_stop_streaming(struct vb2_queue *vq)
 	}
 	dev->usb_ctl.vid_buf = NULL;
 	spin_unlock_irqrestore(&dev->slock, flags);
-
-	return 0;
 }
 
-int em28xx_stop_vbi_streaming(struct vb2_queue *vq)
+void em28xx_stop_vbi_streaming(struct vb2_queue *vq)
 {
 	struct em28xx *dev = vb2_get_drv_priv(vq);
 	struct em28xx_dmaqueue *vbiq = &dev->vbiq;
@@ -989,8 +987,6 @@ int em28xx_stop_vbi_streaming(struct vb2_queue *vq)
 	}
 	dev->usb_ctl.vbi_buf = NULL;
 	spin_unlock_irqrestore(&dev->slock, flags);
-
-	return 0;
 }
 
 static void
diff --git a/drivers/media/usb/pwc/pwc-if.c b/drivers/media/usb/pwc/pwc-if.c
index 84a6720b1d00..a73b0bced96f 100644
--- a/drivers/media/usb/pwc/pwc-if.c
+++ b/drivers/media/usb/pwc/pwc-if.c
@@ -681,12 +681,11 @@ static int start_streaming(struct vb2_queue *vq, unsigned int count)
 	return r;
 }
 
-static int stop_streaming(struct vb2_queue *vq)
+static void stop_streaming(struct vb2_queue *vq)
 {
 	struct pwc_device *pdev = vb2_get_drv_priv(vq);
 
-	if (mutex_lock_interruptible(&pdev->v4l2_lock))
-		return -ERESTARTSYS;
+	mutex_lock(&pdev->v4l2_lock);
 	if (pdev->udev) {
 		pwc_set_leds(pdev, 0, 0);
 		pwc_camera_power(pdev, 0);
@@ -695,8 +694,6 @@ static int stop_streaming(struct vb2_queue *vq)
 
 	pwc_cleanup_queued_bufs(pdev);
 	mutex_unlock(&pdev->v4l2_lock);
-
-	return 0;
 }
 
 static struct vb2_ops pwc_vb_queue_ops = {
diff --git a/drivers/media/usb/s2255/s2255drv.c b/drivers/media/usb/s2255/s2255drv.c
index 1d4ba2b80490..e019dd63ed42 100644
--- a/drivers/media/usb/s2255/s2255drv.c
+++ b/drivers/media/usb/s2255/s2255drv.c
@@ -714,7 +714,7 @@ static void buffer_queue(struct vb2_buffer *vb)
 }
 
 static int start_streaming(struct vb2_queue *vq, unsigned int count);
-static int stop_streaming(struct vb2_queue *vq);
+static void stop_streaming(struct vb2_queue *vq);
 
 static struct vb2_ops s2255_video_qops = {
 	.queue_setup = queue_setup,
@@ -1109,7 +1109,7 @@ static int start_streaming(struct vb2_queue *vq, unsigned int count)
 }
 
 /* abort streaming and wait for last buffer */
-static int stop_streaming(struct vb2_queue *vq)
+static void stop_streaming(struct vb2_queue *vq)
 {
 	struct s2255_vc *vc = vb2_get_drv_priv(vq);
 	struct s2255_buffer *buf, *node;
@@ -1123,7 +1123,6 @@ static int stop_streaming(struct vb2_queue *vq)
 			buf, buf->vb.v4l2_buf.index);
 	}
 	spin_unlock_irqrestore(&vc->qlock, flags);
-	return 0;
 }
 
 static int vidioc_s_std(struct file *file, void *priv, v4l2_std_id i)
diff --git a/drivers/media/usb/stk1160/stk1160-v4l.c b/drivers/media/usb/stk1160/stk1160-v4l.c
index 37bc00f418f1..46e8a5069b37 100644
--- a/drivers/media/usb/stk1160/stk1160-v4l.c
+++ b/drivers/media/usb/stk1160/stk1160-v4l.c
@@ -583,10 +583,10 @@ static int start_streaming(struct vb2_queue *vq, unsigned int count)
 }
 
 /* abort streaming and wait for last buffer */
-static int stop_streaming(struct vb2_queue *vq)
+static void stop_streaming(struct vb2_queue *vq)
 {
 	struct stk1160 *dev = vb2_get_drv_priv(vq);
-	return stk1160_stop_streaming(dev);
+	stk1160_stop_streaming(dev);
 }
 
 static struct vb2_ops stk1160_video_qops = {
diff --git a/drivers/media/usb/usbtv/usbtv-video.c b/drivers/media/usb/usbtv/usbtv-video.c
index 20365bd69d05..2967e808408b 100644
--- a/drivers/media/usb/usbtv/usbtv-video.c
+++ b/drivers/media/usb/usbtv/usbtv-video.c
@@ -634,15 +634,12 @@ static int usbtv_start_streaming(struct vb2_queue *vq, unsigned int count)
 	return usbtv_start(usbtv);
 }
 
-static int usbtv_stop_streaming(struct vb2_queue *vq)
+static void usbtv_stop_streaming(struct vb2_queue *vq)
 {
 	struct usbtv *usbtv = vb2_get_drv_priv(vq);
 
-	if (usbtv->udev == NULL)
-		return -ENODEV;
-
-	usbtv_stop(usbtv);
-	return 0;
+	if (usbtv->udev)
+		usbtv_stop(usbtv);
 }
 
 static struct vb2_ops usbtv_vb2_ops = {