media: amphion: Clear last_buffer_dequeued flag for DEC_CMD_START

[ Upstream commit d85f320 ]

The V4L2_DEC_CMD_START command may be used to handle the dynamic source
change, which will triggers an implicit decoder drain.
The last_buffer_dequeued flag is set in the implicit decoder drain,
so driver need to clear it to continue the following decoding flow.

Signed-off-by: Ming Qian <ming.qian@oss.nxp.com>
Reviewed-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Signed-off-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
(cherry picked from commit f5a5a824f0acbf331ea89aada14546ddfc4166b0)
Signed-off-by: Wentao Guan <guanwentao@uniontech.com>

Author: Ming Qian

drivers/media/platform/amphion/vdec.c

@@ -630,6 +630,7 @@ static int vdec_decoder_cmd(struct file *file, void *fh, struct v4l2_decoder_cmd
 	switch (cmd->cmd) {
 	case V4L2_DEC_CMD_START:
 		vdec_cmd_start(inst);
+		vb2_clear_last_buffer_dequeued(v4l2_m2m_get_dst_vq(inst->fh.m2m_ctx));
 		break;
 	case V4L2_DEC_CMD_STOP:
 		vdec_cmd_stop(inst);