Re: [Intel-gfx] [PATCH] drm/i915: Allow panel fixed modes to have differing sync polarities

[Jani Nikula <jani.nikula@linux.intel.com>]

On Fri, 07 Oct 2022, Ville Syrjala <ville.syrjala@linux.intel.com> wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> Apparently some panels declare multiple modes with random
> sync polarities. Seems a bit weird, but looks like Windows/GOP
> doesn't care, so let follow suit and accept alternate fixed
> modes regardless of their sync polarities.
>
> Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/6968
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_panel.c | 10 +++++++---
>  1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_panel.c b/drivers/gpu/drm/i915/display/intel_panel.c
> index 2b4b359b8342..fdeb1cd608c3 100644
> --- a/drivers/gpu/drm/i915/display/intel_panel.c
> +++ b/drivers/gpu/drm/i915/display/intel_panel.c
> @@ -82,12 +82,16 @@ static bool is_alt_drrs_mode(const struct drm_display_mode *mode,
>  		mode->clock != preferred_mode->clock;
>  }
>  
> +#define DRM_MODE_FLAG_SYNC_MASK (DRM_MODE_FLAG_PHSYNC | \
> +				 DRM_MODE_FLAG_NHSYNC | \
> +				 DRM_MODE_FLAG_PVSYNC | \
> +				 DRM_MODE_FLAG_NVSYNC)

Maybe not the best to name the macro in the DRM_MODE_* "namespace"?

Other than that,

Acked-by: Jani Nikula <jani.nikula@intel.com>


> +
>  static bool is_alt_fixed_mode(const struct drm_display_mode *mode,
>  			      const struct drm_display_mode *preferred_mode)
>  {
> -	return drm_mode_match(mode, preferred_mode,
> -			      DRM_MODE_MATCH_FLAGS |
> -			      DRM_MODE_MATCH_3D_FLAGS) &&
> +	return (mode->flags & ~DRM_MODE_FLAG_SYNC_MASK) ==
> +		(preferred_mode->flags & ~DRM_MODE_FLAG_SYNC_MASK) &&
>  		mode->hdisplay == preferred_mode->hdisplay &&
>  		mode->vdisplay == preferred_mode->vdisplay;
>  }

-- 
Jani Nikula, Intel Open Source Graphics Center