Re: [igt-dev] [PATCH 1/2] tests/kms_plane: Handle hw without legacy gamma support

[Abhinav Kumar <quic_abhinavk@quicinc.com>]

On 8/8/2023 7:53 AM, Rob Clark wrote:
> From: Rob Clark <robdclark@chromium.org>
> 
> Skip the legacy gamma on hw that doesn't support it, instead of failing.
> The legacy LUT support was used to drop the precision down to 6 bits, to
> paper over errors introduced y RGB<->YCbCr conversion, but this isn't
> necessarily needed on all hw.
> 
> v2: igt_require(lut_size > 0) instead
> v3: simplify patch
> 
> Signed-off-by: Rob Clark <robdclark@chromium.org>
> Reviewed-by: Juha-Pekka Heikkila <juhapekka.heikkila@gmail.com>

Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Tested-by: Abhinav Kumar <quic_abhinavk@quicinc.com> # sc7280

> ---
>   tests/kms_plane.c | 4 ++++
>   1 file changed, 4 insertions(+)
> 
> diff --git a/tests/kms_plane.c b/tests/kms_plane.c
> index 67cff61d6cd1..a444cdca23e2 100644
> --- a/tests/kms_plane.c
> +++ b/tests/kms_plane.c
> @@ -469,6 +469,10 @@ static void set_legacy_lut(data_t *data, enum pipe pipe,
>   	lut_size = crtc->gamma_size;
>   	drmModeFreeCrtc(crtc);
>   
> +	/* Skip if legacy LUT is not supported: */
> +	if (!lut_size)
> +		return;
> +
>   	lut = malloc(sizeof(uint16_t) * lut_size);
>   
>   	for (i = 0; i < lut_size; i++)