[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>

7 files changed, 15 insertions, 31 deletions

diff --git a/drivers/staging/media/davinci_vpfe/vpfe_video.c b/drivers/staging/media/davinci_vpfe/vpfe_video.c
index 9337d92..7b213a7 100644
--- a/drivers/staging/media/davinci_vpfe/vpfe_video.c
+++ b/drivers/staging/media/davinci_vpfe/vpfe_video.c
@@ -1249,7 +1249,7 @@ static int vpfe_buffer_init(struct vb2_buffer *vb)
 }
 
 /* abort streaming and wait for last buffer */
-static int vpfe_stop_streaming(struct vb2_queue *vq)
+static void vpfe_stop_streaming(struct vb2_queue *vq)
 {
 	struct vpfe_fh *fh = vb2_get_drv_priv(vq);
 	struct vpfe_video_device *video = fh->video;
@@ -1272,7 +1272,6 @@ static int vpfe_stop_streaming(struct vb2_queue *vq)
 		list_del(&video->next_frm->list);
 		vb2_buffer_done(&video->next_frm->vb, VB2_BUF_STATE_ERROR);
 	}
-	return 0;
 }
 
 static void vpfe_buf_cleanup(struct vb2_buffer *vb)
diff --git a/drivers/staging/media/dt3155v4l/dt3155v4l.c b/drivers/staging/media/dt3155v4l/dt3155v4l.c
index afbc2e5..14bdc19 100644
--- a/drivers/staging/media/dt3155v4l/dt3155v4l.c
+++ b/drivers/staging/media/dt3155v4l/dt3155v4l.c
@@ -262,7 +262,7 @@ dt3155_buf_prepare(struct vb2_buffer *vb)
 	return 0;
 }
 
-static int
+static void
 dt3155_stop_streaming(struct vb2_queue *q)
 {
 	struct dt3155_priv *pd = vb2_get_drv_priv(q);
@@ -276,7 +276,6 @@ dt3155_stop_streaming(struct vb2_queue *q)
 	}
 	spin_unlock_irq(&pd->lock);
 	msleep(45); /* irq hendler will stop the hardware */
-	return 0;
 }
 
 static void
diff --git a/drivers/staging/media/go7007/go7007-v4l2.c b/drivers/staging/media/go7007/go7007-v4l2.c
index b397aa3..090b3e6 100644
--- a/drivers/staging/media/go7007/go7007-v4l2.c
+++ b/drivers/staging/media/go7007/go7007-v4l2.c
@@ -516,7 +516,7 @@ static int go7007_start_streaming(struct vb2_queue *q, unsigned int count)
 	return ret;
 }
 
-static int go7007_stop_streaming(struct vb2_queue *q)
+static void go7007_stop_streaming(struct vb2_queue *q)
 {
 	struct go7007 *go = vb2_get_drv_priv(q);
 	unsigned long flags;
@@ -538,7 +538,6 @@ static int go7007_stop_streaming(struct vb2_queue *q)
 	/* Turn on Capture LED */
 	if (go->board_id == GO7007_BOARDID_ADS_USBAV_709)
 		go7007_write_addr(go, 0x3c82, 0x000d);
-	return 0;
 }
 
 static struct vb2_ops go7007_video_qops = {
diff --git a/drivers/staging/media/msi3101/sdr-msi3101.c b/drivers/staging/media/msi3101/sdr-msi3101.c
index 65d351f..08d0d09 100644
--- a/drivers/staging/media/msi3101/sdr-msi3101.c
+++ b/drivers/staging/media/msi3101/sdr-msi3101.c
@@ -1074,14 +1074,13 @@ static int msi3101_start_streaming(struct vb2_queue *vq, unsigned int count)
 	return ret;
 }
 
-static int msi3101_stop_streaming(struct vb2_queue *vq)
+static void msi3101_stop_streaming(struct vb2_queue *vq)
 {
 	struct msi3101_state *s = vb2_get_drv_priv(vq);
-	int ret;
+
 	dev_dbg(&s->udev->dev, "%s:\n", __func__);
 
-	if (mutex_lock_interruptible(&s->v4l2_lock))
-		return -ERESTARTSYS;
+	mutex_lock(&s->v4l2_lock);
 
 	if (s->udev)
 		msi3101_isoc_cleanup(s);
@@ -1090,22 +1089,15 @@ static int msi3101_stop_streaming(struct vb2_queue *vq)
 
 	/* according to tests, at least 700us delay is required  */
 	msleep(20);
-	ret = msi3101_ctrl_msg(s, CMD_STOP_STREAMING, 0);
-	if (ret)
-		goto err_sleep_tuner;
-
-	/* sleep USB IF / ADC */
-	ret = msi3101_ctrl_msg(s, CMD_WREG, 0x01000003);
-	if (ret)
-		goto err_sleep_tuner;
+	if (!msi3101_ctrl_msg(s, CMD_STOP_STREAMING, 0)) {
+		/* sleep USB IF / ADC */
+		msi3101_ctrl_msg(s, CMD_WREG, 0x01000003);
+	}
 
-err_sleep_tuner:
 	/* sleep tuner */
-	ret = v4l2_subdev_call(s->v4l2_subdev, core, s_power, 0);
+	v4l2_subdev_call(s->v4l2_subdev, core, s_power, 0);
 
 	mutex_unlock(&s->v4l2_lock);
-
-	return ret;
 }
 
 static struct vb2_ops msi3101_vb2_ops = {
diff --git a/drivers/staging/media/rtl2832u_sdr/rtl2832_sdr.c b/drivers/staging/media/rtl2832u_sdr/rtl2832_sdr.c
index 104ee8a..093df6b 100644
--- a/drivers/staging/media/rtl2832u_sdr/rtl2832_sdr.c
+++ b/drivers/staging/media/rtl2832u_sdr/rtl2832_sdr.c
@@ -1032,13 +1032,12 @@ err:
 	return ret;
 }
 
-static int rtl2832_sdr_stop_streaming(struct vb2_queue *vq)
+static void rtl2832_sdr_stop_streaming(struct vb2_queue *vq)
 {
 	struct rtl2832_sdr_state *s = vb2_get_drv_priv(vq);
 	dev_dbg(&s->udev->dev, "%s:\n", __func__);
 
-	if (mutex_lock_interruptible(&s->v4l2_lock))
-		return -ERESTARTSYS;
+	mutex_lock(&s->v4l2_lock);
 
 	rtl2832_sdr_kill_urbs(s);
 	rtl2832_sdr_free_urbs(s);
@@ -1053,8 +1052,6 @@ static int rtl2832_sdr_stop_streaming(struct vb2_queue *vq)
 		s->d->props->power_ctrl(s->d, 0);
 
 	mutex_unlock(&s->v4l2_lock);
-
-	return 0;
 }
 
 static struct vb2_ops rtl2832_sdr_vb2_ops = {
diff --git a/drivers/staging/media/solo6x10/solo6x10-v4l2-enc.c b/drivers/staging/media/solo6x10/solo6x10-v4l2-enc.c
index 2cbe088..b8ff113 100644
--- a/drivers/staging/media/solo6x10/solo6x10-v4l2-enc.c
+++ b/drivers/staging/media/solo6x10/solo6x10-v4l2-enc.c
@@ -745,14 +745,13 @@ static int solo_enc_start_streaming(struct vb2_queue *q, unsigned int count)
 	return solo_ring_start(solo_enc->solo_dev);
 }
 
-static int solo_enc_stop_streaming(struct vb2_queue *q)
+static void solo_enc_stop_streaming(struct vb2_queue *q)
 {
 	struct solo_enc_dev *solo_enc = vb2_get_drv_priv(q);
 
 	solo_enc_off(solo_enc);
 	INIT_LIST_HEAD(&solo_enc->vidq_active);
 	solo_ring_stop(solo_enc->solo_dev);
-	return 0;
 }
 
 static struct vb2_ops solo_enc_video_qops = {
diff --git a/drivers/staging/media/solo6x10/solo6x10-v4l2.c b/drivers/staging/media/solo6x10/solo6x10-v4l2.c
index 1815f76..5d0100e 100644
--- a/drivers/staging/media/solo6x10/solo6x10-v4l2.c
+++ b/drivers/staging/media/solo6x10/solo6x10-v4l2.c
@@ -336,13 +336,12 @@ static int solo_start_streaming(struct vb2_queue *q, unsigned int count)
 	return solo_start_thread(solo_dev);
 }
 
-static int solo_stop_streaming(struct vb2_queue *q)
+static void solo_stop_streaming(struct vb2_queue *q)
 {
 	struct solo_dev *solo_dev = vb2_get_drv_priv(q);
 
 	solo_stop_thread(solo_dev);
 	INIT_LIST_HEAD(&solo_dev->vidq_active);
-	return 0;
 }
 
 static void solo_buf_queue(struct vb2_buffer *vb)