[Intel-gfx] [PATCH] drm/i915: Postpone plane readout until after encoder readout

[Maarten Lankhorst]

Hey,

Op 31-07-15 om 15:04 schreef Patrik Jakobsson:
> When reading out hw state for planes we disable inactive planes which in
> turn triggers an update of the watermarks. The update depends on the
> crtc_clock being set which is done when reading out encoders. Thus
> postpone the plane readout until after encoder readout.
>
> This prevents a warning in skl_compute_linetime_wm() where pixel_rate
> becomes 0 when crtc_clock is 0.
>
Running this on skylake it looks like like it's a partial fix.
You would need to move hwmode like below too?

Also:

References: https://bugs.freedesktop.org/show_bug.cgi?id=91428

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index add7f807a82d..49907f4e939a 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -14888,8 +14888,6 @@ static void intel_modeset_readout_hw_state(struct drm_device *dev)
 			crtc->base.state->mode.private_flags = I915_MODE_FLAG_INHERITED;
 		}
 
-		crtc->base.hwmode = crtc->config->base.adjusted_mode;
-
 		DRM_DEBUG_KMS("[CRTC:%d] hw state readout: %s\n",
 			      crtc->base.base.id,
 			      crtc->active ? "enabled" : "disabled");
@@ -14971,6 +14969,7 @@ intel_modeset_setup_hw_state(struct drm_device *dev)
 
 	for_each_pipe(dev_priv, pipe) {
 		crtc = to_intel_crtc(dev_priv->pipe_to_crtc_mapping[pipe]);
+		crtc->base.hwmode = crtc->config->base.adjusted_mode;
 
 		for_each_intel_plane(crtc->base.dev, plane) {
 			if (crtc->pipe != plane->pipe)