[PATCH v7 11/19] media: meson: vdec: Update core m2m stream state during transitions

[Anand Moon]

Explicitly update the V4L2 core Memory-to-Memory (m2m) framework's
internal streaming states when initiating or terminating streaming on
the device queues.

Without invoking these core framework helpers, the m2m engine's
bookkeeping of active source and destination queues drifts out of
alignment with the driver's local 'streamon_out' and 'streamon_cap'
tracking variables. This misalignment causes state validation stalls
and incorrect polling outcomes when the device is subjected to quick
runtime cycles or strict testing setups (such as v4l2-compliance).

Fix this by integrating v4l2_m2m_update_start_streaming_state() right
after a queue is marked active in vdec_start_streaming(), and pairing
it cleanly with v4l2_m2m_update_stop_streaming_state() at the end of
vdec_stop_streaming() before the session core mutex is released.

Cc: Nicolas Dufresne <nicolas at ndufresne.ca>
Signed-off-by: Anand Moon <linux.amoon at gmail.com>
---
 drivers/staging/media/meson/vdec/vdec.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/staging/media/meson/vdec/vdec.c b/drivers/staging/media/meson/vdec/vdec.c
index 83a9b1238972a..0eb39aa6014ee 100644
--- a/drivers/staging/media/meson/vdec/vdec.c
+++ b/drivers/staging/media/meson/vdec/vdec.c
@@ -299,6 +299,8 @@ static int vdec_start_streaming(struct vb2_queue *q, unsigned int count)
 	else
 		sess->streamon_cap = 1;
 
+	v4l2_m2m_update_start_streaming_state(sess->m2m_ctx, q);
+
 	if (!sess->streamon_out)
 		return 0;
 
@@ -529,6 +531,8 @@ static void vdec_stop_streaming(struct vb2_queue *q)
 			sess->changed_format = 0;
 	}
 
+	v4l2_m2m_update_stop_streaming_state(sess->m2m_ctx, q);
+
 	mutex_unlock(&core->lock);
 }
 
-- 
2.50.1