Re: [PATCH v3 13/23] media: iris: Send V4L2_BUF_FLAG_ERROR for buffers with 0 filled length

[Bryan O'Donoghue]

On 01/05/2025 20:13, Dikshita Agarwal wrote:
> Firmware sends buffers with 0 filled length which needs to be dropped,
> to achieve the same, add V4L2_BUF_FLAG_ERROR to such buffers.
> Also make sure:
> - These 0 length buffers are not returned as result of flush.
> - Its not a buffer with LAST flag enabled which will also have 0 filled
>    length.
>
> Acked-by: Vikash Garodia <quic_vgarodia@xxxxxxxxxxx>
> Signed-off-by: Dikshita Agarwal <quic_dikshita@xxxxxxxxxxx>
> ---
>   drivers/media/platform/qcom/iris/iris_hfi_gen2_response.c | 6 ++++++
>   1 file changed, 6 insertions(+)
>
> diff --git a/drivers/media/platform/qcom/iris/iris_hfi_gen2_response.c b/drivers/media/platform/qcom/iris/iris_hfi_gen2_response.c
> index 4488540d1d41..3bb326843a7b 100644
> --- a/drivers/media/platform/qcom/iris/iris_hfi_gen2_response.c
> +++ b/drivers/media/platform/qcom/iris/iris_hfi_gen2_response.c
> @@ -378,6 +378,12 @@ static int iris_hfi_gen2_handle_output_buffer(struct iris_inst *inst,
>   
>   	buf->flags = iris_hfi_gen2_get_driver_buffer_flags(inst, hfi_buffer->flags);
>   
> +	if (!buf->data_size && inst->state == IRIS_INST_STREAMING &&
> +	    !(hfi_buffer->flags & HFI_BUF_FW_FLAG_LAST) &&
> +	    !(inst->sub_state & IRIS_INST_SUB_DRC)) {
> +		buf->flags |= V4L2_BUF_FLAG_ERROR;
> +	}
> +
>   	return 0;
>   }
>   

This is a pretty complex conjunctive clause.

Is it possible for say 1/3 of these logical criteria to be false ?

i.e. if you get to:

1. buf->data_size && inst->state == IRIS_INST_STREAMING
2. !(hfi_buffer->flags & HFI_BUF_FW_FLAG_LAST)

is it possible to get to

3. !(inst->sub_state & IRIS_INST_SUB_DRC)

?

This also feels like a bugfix ?

---
bod