[PATCH v7 14/19] media: meson: vdec: Correct atomic counter placement in dst_buf_done

[Anand Moon]

Fix an end-of-stream (EOS) boundary condition logic flaw in
dst_buf_done() by relocating the atomic decrement helper to execute
after state evaluation.

Previously, decrementing sess->esparser_queued_bufs at the entry point
of the function corrupted the conditional checks for the final video
frame. This premature decrement tricked the driver into flagging the
second-to-last buffer as the final frame (V4L2_BUF_FLAG_LAST) during
teardown sequences, which cut off the true final frame and broke
compliance validation.

Resolve this by moving atomic_dec() to execute immediately after the EOS
conditional tracking block finishes evaluating, right before invoking
v4l2_m2m_buf_done(). This ensures accurate stream termination
signaling.

Cc: Nicolas Dufresne <nicolas at ndufresne.ca>
Signed-off-by: Anand Moon <linux.amoon at gmail.com>
---
 drivers/staging/media/meson/vdec/vdec_helpers.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/staging/media/meson/vdec/vdec_helpers.c b/drivers/staging/media/meson/vdec/vdec_helpers.c
index f02c21d5a9c18..303236f0647c0 100644
--- a/drivers/staging/media/meson/vdec/vdec_helpers.c
+++ b/drivers/staging/media/meson/vdec/vdec_helpers.c
@@ -314,6 +314,9 @@ static void dst_buf_done(struct amvdec_session *sess,
 	dev_dbg(dev, "Buffer %u done, ts = %llu, flags = %08X\n",
 		vbuf->vb2_buf.index, timestamp, flags);
 	vbuf->field = field;
+
+	atomic_dec(&sess->esparser_queued_bufs);
+
 	v4l2_m2m_buf_done(vbuf, VB2_BUF_STATE_DONE);
 
 	/* Buffer done probably means the vififo got freed */
-- 
2.50.1