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

[José Roberto de Souza]

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);
 	}
 }
 
-- 
2.30.1