[PATCH v2 03/13] media: stm32: dcmipp: bytecap: protect CMIER register access

[Alain Volmat]

CMIER register is common between all pipes and thus needs to be
protected from concurrent access.  The struct v4l2_device structure,
unique to the whole driver embeds a spin_lock which can also be used
by the driver itself as explained in its description.  Rely on this
spin_lock to protect from concurrent access to the CMIER register.

Signed-off-by: Alain Volmat <alain.volmat at foss.st.com>
---
 drivers/media/platform/st/stm32/stm32-dcmipp/dcmipp-bytecap.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/media/platform/st/stm32/stm32-dcmipp/dcmipp-bytecap.c b/drivers/media/platform/st/stm32/stm32-dcmipp/dcmipp-bytecap.c
index 990bbaaf4bda..dac7338dd981 100644
--- a/drivers/media/platform/st/stm32/stm32-dcmipp/dcmipp-bytecap.c
+++ b/drivers/media/platform/st/stm32/stm32-dcmipp/dcmipp-bytecap.c
@@ -436,7 +436,9 @@ static int dcmipp_bytecap_start_streaming(struct vb2_queue *vq,
 	dcmipp_start_capture(vcap, vcap->next);
 
 	/* Enable interruptions */
+	spin_lock(&vcap->vdev.v4l2_dev->lock);
 	reg_set(vcap, DCMIPP_CMIER, DCMIPP_CMIER_P0ALL);
+	spin_unlock(&vcap->vdev.v4l2_dev->lock);
 
 	vcap->state = DCMIPP_RUNNING;
 
@@ -492,7 +494,9 @@ static void dcmipp_bytecap_stop_streaming(struct vb2_queue *vq)
 	media_pipeline_stop(vcap->vdev.entity.pads);
 
 	/* Disable interruptions */
+	spin_lock(&vcap->vdev.v4l2_dev->lock);
 	reg_clear(vcap, DCMIPP_CMIER, DCMIPP_CMIER_P0ALL);
+	spin_unlock(&vcap->vdev.v4l2_dev->lock);
 
 	/* Stop capture */
 	reg_clear(vcap, DCMIPP_P0FCTCR, DCMIPP_P0FCTCR_CPTREQ);

-- 
2.43.0