diff mbox series

[04/28] media: coda: fix last buffer handling in V4L2_ENC_CMD_STOP

Message ID 20190618164535.20162-5-p.zabel@pengutronix.de (mailing list archive)
State New, archived
Headers show
Series media: coda: fixes and improvements | expand

Commit Message

Philipp Zabel June 18, 2019, 4:45 p.m. UTC 
From: Marco Felsch <m.felsch@pengutronix.de>

coda_encoder_cmd() is racy, as the last scheduled picture run worker can
still be in-flight while the ENC_CMD_STOP command is issued. Depending
on the exact timing the sequence numbers might already be changed, but
the last buffer might not have been put on the destination queue yet.

In this case the current implementation would prematurely wake the
destination queue with last_buffer_dequeued=true, causing userspace to
call streamoff before the last buffer is handled.

Close this race window by synchronizing with the pic_run_worker before
doing the sequence check.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
[l.stach@pengutronix.de: switch to flush_work, reword commit message]
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
---
 drivers/media/platform/coda/coda-common.c | 2 ++
 1 file changed, 2 insertions(+)
diff mbox series

Patch

diff --git a/drivers/media/platform/coda/coda-common.c b/drivers/media/platform/coda/coda-common.c
index e09d48170e5c..d3b1e7b87a8a 100644
--- a/drivers/media/platform/coda/coda-common.c
+++ b/drivers/media/platform/coda/coda-common.c
@@ -1018,6 +1018,8 @@  static int coda_encoder_cmd(struct file *file, void *fh,
 	/* Set the stream-end flag on this context */
 	ctx->bit_stream_param |= CODA_BIT_STREAM_END_FLAG;
 
+	flush_work(&ctx->pic_run_work);
+
 	/* If there is no buffer in flight, wake up */
 	if (!ctx->streamon_out || ctx->qsequence == ctx->osequence) {
 		dst_vq = v4l2_m2m_get_vq(ctx->fh.m2m_ctx,