Re: [PATCH v2 6/6] media: iris: Prevent output buffer queuing before stream-on completes

[Vikash Garodia <vikash.garodia@oss.qualcomm.com>]

On 12/29/2025 12:01 PM, Dikshita Agarwal wrote:
> From: Vishnu Reddy <busanna.reddy@oss.qualcomm.com>
> 
> During normal playback, stream-on for input is followed by output, and
> only after input stream-on does actual streaming begin. However, when
> gst-play performs a seek, both input and output streams are stopped,
> and on restart, output stream-on occurs first. At this point, firmware
> has not yet started streaming. Queuing output buffers before the firmware
> begins streaming causes it to process buffers in an invalid state, leading
> to an error response. These buffers are returned to the driver as errors,
> forcing the driver into an error state and stopping playback.
> 
> Fix this by deferring output buffer queuing until stream-on completes.
> Input buffers can still be queued before stream-on as required.
> 
> Fixes: 92e007ca5ab6 ("media: iris: Add V4L2 streaming support for encoder video device")
> Signed-off-by: Vishnu Reddy <busanna.reddy@oss.qualcomm.com>
> Signed-off-by: Dikshita Agarwal <dikshita.agarwal@oss.qualcomm.com>
> ---
>   drivers/media/platform/qcom/iris/iris_vb2.c | 10 +++++++---
>   1 file changed, 7 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/media/platform/qcom/iris/iris_vb2.c b/drivers/media/platform/qcom/iris/iris_vb2.c
> index 139b821f7952feb33b21a7045aef9e8a4782aa3c..bf0b8400996ece5c9d449b99609a302da726bf9a 100644
> --- a/drivers/media/platform/qcom/iris/iris_vb2.c
> +++ b/drivers/media/platform/qcom/iris/iris_vb2.c
> @@ -193,10 +193,14 @@ int iris_vb2_start_streaming(struct vb2_queue *q, unsigned int count)
>   	buf_type = iris_v4l2_type_to_driver(q->type);
>   
>   	if (inst->domain == DECODER) {
> -		if (inst->state == IRIS_INST_STREAMING)
> +		if (buf_type == BUF_INPUT)
> +			ret = iris_queue_deferred_buffers(inst, BUF_INPUT);
> +
> +		if (!ret && inst->state == IRIS_INST_STREAMING) {
>   			ret = iris_queue_internal_deferred_buffers(inst, BUF_DPB);
> -		if (!ret)
> -			ret = iris_queue_deferred_buffers(inst, buf_type);
> +			if (!ret)
> +				ret = iris_queue_deferred_buffers(inst, BUF_OUTPUT);
> +		}
>   	} else {
>   		if (inst->state == IRIS_INST_STREAMING) {
>   			ret = iris_queue_deferred_buffers(inst, BUF_INPUT);
> 

Reviewed-by: Vikash Garodia<vikash.garodia@oss.qualcomm.com>