Re: [PATCH 1/2] media: iris: avoid bit depth validation for capture formats

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

On 7/7/2026 12:05 PM, Vishnu Reddy wrote:
> When validating a capture format, check_format() compares the requested
> pixel format against inst->fw_caps[BIT_DEPTH]. However, the bit depth
> capability is not available at this stage and it contains the default
> value of BIT_DEPTH_8. The actual bit depth is updated later after the
> firmware reports stream capabilities through read_input_subcr_params().
> Because of this, a valid QC10C format request is rejected during the

client request

> initial format negotiation. The driver then falls back to the default
> capture format (NV12) and stores it as capture format.
> 

No new line

> Later, when the firmware reports that the stream is 10-bit, the driver
> sees NV12 as the selected capture format and switches to the default
> 10-bit format (P010). As a result, the original QC10C format requested
> by userspace is lost and QC10C decoding cannot work correctly.
> 

No new line.

> The bit depth information is not reliable during the initial format
> setup, so it should not be used to validate capture formats. Remove
> the bit-depth checks from check_format() and only verify that the
> requested pixel format is supported. This allows the format requested
> by userspace is handled correctly.
> 
> Fixes: 20c3ef4c7cae ("media: qcom: iris: vdec: update find_format to handle 8bit and 10bit formats")
> Cc: stable@vger.kernel.org
> Signed-off-by: Vishnu Reddy <busanna.reddy@oss.qualcomm.com>
> ---
>   drivers/media/platform/qcom/iris/iris_vdec.c | 10 ----------
>   1 file changed, 10 deletions(-)
> 
> diff --git a/drivers/media/platform/qcom/iris/iris_vdec.c b/drivers/media/platform/qcom/iris/iris_vdec.c
> index 9e228b70420e..7f89e745a4b1 100644
> --- a/drivers/media/platform/qcom/iris/iris_vdec.c
> +++ b/drivers/media/platform/qcom/iris/iris_vdec.c
> @@ -95,16 +95,6 @@ static bool check_format(struct iris_inst *inst, u32 pixfmt, u32 type)
>   	if (i == size)
>   		return false;
>   
> -	if (type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE) {
> -		if (iris_fmt_is_8bit(pixfmt) &&
> -		    inst->fw_caps[BIT_DEPTH].value == BIT_DEPTH_10)
> -			return false;
> -
> -		if (iris_fmt_is_10bit(pixfmt) &&
> -		    inst->fw_caps[BIT_DEPTH].value != BIT_DEPTH_10)
> -			return false;
> -	}
> -
>   	return true;
>   }
>   
>