Re: [PATCH v7 0/3] drm/i915/display: Try YCbCr420 color when RGB fails

[Ville Syrjälä]

On Mon, May 10, 2021 at 03:33:46PM +0200, Werner Sembach wrote:
> When encoder validation of a display mode fails, retry with less bandwidth
> heavy YCbCr420 color mode, if available. This enables some HDMI 1.4 setups
> to support 4k60Hz output, which previously failed silently.
> 
> AMDGPU had nearly the exact same issue. This problem description is
> therefore copied from my commit message of the AMDGPU patch.
> 
> On some setups, while the monitor and the gpu support display modes with
> pixel clocks of up to 600MHz, the link encoder might not. This prevents
> YCbCr444 and RGB encoding for 4k60Hz, but YCbCr420 encoding might still be
> possible. However, which color mode is used is decided before the link
> encoder capabilities are checked. This patch fixes the problem by retrying
> to find a display mode with YCbCr420 enforced and using it, if it is
> valid.
> 
> This patchset is revision 7. Fixed a rebase issue in 1/3 and moved message
> from error output to debug output in 2/3.

Looks good and CI seem shappy. 

Series pushed to drm-intel-next. Thanks.

-- 
Ville Syrjälä
Intel