[Intel-gfx] [PATCH] drm/i915/color: fix broken display in icl+

[Jani Nikula]

On Tue, 01 Oct 2019, Swati Sharma <swati2.sharma at intel.com> wrote:
> Premature gamma lut prepration and loading which was getting
> reflected in first modeset causing different colors on
> screen during boot.
>
> Issue: In BIOS, gamma is disabled by default. However,
> legacy_read_luts() was getting called even before the legacy_load_luts()
> which was setting crtc_state->base.gamma_lut and gamma_lut was
> programmed with junk values which led to visual artifacts (different
> colored screens instead of usual black during boot).
>
> Fix: Calling read_luts() only when gamma is enabled which will happen
> after first modeset.
>
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=111809

I'm confused. Is there a current problem upstream after the revert
1b8588741fdc ("Revert "drm/i915/color: Extract icl_read_luts()"")?

Or does this fix a problem that only occurs in conjunction with the
reverted commit? Then say so.

Note inline.

> Signed-off-by: Swati Sharma <swati2.sharma at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_display.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index f1328c08f4ad..f89aa4bb9f42 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -10528,7 +10528,9 @@ static bool haswell_get_pipe_config(struct intel_crtc *crtc,
>  		i9xx_get_pipe_color_config(pipe_config);
>  	}
>  
> -	intel_color_get_config(pipe_config);
> +	if ((INTEL_GEN(dev_priv) >= 11 && (pipe_config->gamma_mode & POST_CSC_GAMMA_ENABLE)) ||
> +	   (INTEL_GEN(dev_priv) >= 9 && (pipe_config->gamma_enable)))
> +			intel_color_get_config(pipe_config);

Put all of the conditions inside intel_color_get_config().

BR,
Jani.


>  
>  	power_domain = POWER_DOMAIN_PIPE_PANEL_FITTER(crtc->pipe);
>  	WARN_ON(power_domain_mask & BIT_ULL(power_domain));

-- 
Jani Nikula, Intel Open Source Graphics Center