[PATCH v2 3/4] drm: lcdif: Switch to limited range for RGB to YUV conversion

Liu Ying victor.liu at oss.nxp.com
Thu Sep 29 08:06:14 UTC 2022


On Wed, 2022-09-28 at 03:58 +0300, Laurent Pinchart wrote:
> Up to and including v1.3, HDMI supported limited quantization range only
> for YCbCr. HDMI v1.4 introduced selectable quantization ranges, but this
> features isn't supported in the dw-hdmi driver that is used in

s/features/feature/

> conjunction with the LCDIF in the i.MX8MP. The HDMI YCbCr output is thus
> always advertised in the AVI infoframe as limited range.
> 
> The LCDIF driver, on the other hand, configures the CSC to produce full
> range YCbCr. This mismatch results in loss of details and incorrect
> colours. Fix it by switching to limited range YCbCr.
> 
> The coefficients are copied from drivers/media/platforms/nxp/imx-pxp.c
> for coherency, as the hardware is most likely identical.
> 
> Fixes: 9db35bb349a0 ("drm: lcdif: Add support for i.MX8MP LCDIF variant")
> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> ---
> Changes since v1:
> 
> - Use coefficients from imx-pxp.c
> ---
>  drivers/gpu/drm/mxsfb/lcdif_kms.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)

With the typo in commit message fixed:

Reviewed-by: Liu Ying <victor.liu at nxp.com>



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