[Intel-gfx] [PATCH] drm/i915/display: Read planes watermarks during initial state readout

[Ville Syrjälä]

On Fri, Feb 19, 2021 at 11:16:23AM -0800, José Roberto de Souza wrote:
> Without this readout all plane watermarks will be kept at zero in the
> initial state readount causing two problems.
> 
> All active planes will always have their watermarks programmed
> again, even if what firmware programmed matches with the sanitized
> state during driver takeover.
> 
> State mismatch errors in disabled planes as watermarks will erroneous
> match with the calculated state if firmware left watermark registers
> with non-zero values.
> 
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_display.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index d0da88751c72..14fba4411be7 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -13620,6 +13620,8 @@ static void intel_modeset_readout_hw_state(struct drm_device *dev)
>  			drm_calc_timestamping_constants(&slave->base,
>  							&slave_crtc_state->hw.adjusted_mode);
>  		}
> +
> +		skl_pipe_wm_get_hw_state(crtc, &crtc_state->wm.skl.optimal);

Strange. skl_wm_get_hw_state() should be doing this already.

>  	}
>  }
>  
> -- 
> 2.30.1

-- 
Ville Syrjälä
Intel