[Intel-gfx] [PATCH v2 13/14] drm/i915/skl: Update watermarks before the crtc is disabled.

[Maarten Lankhorst]

On skylake some of the registers are only writable when the correct
power wells are enabled. Because of this watermarks have to be updated
before the crtc turns off, or you get unclaimed register read and write
warnings.

This patch needs to be modified slightly to apply to -fixes.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=92181
Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
Cc: stable at vger.kernel.org
Cc: Matt Roper <matthew.d.roper at intel.com>
---
 drivers/gpu/drm/i915/intel_display.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index ecd3169b45ef..304e1028c9a4 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -4758,7 +4758,7 @@ static void intel_post_plane_update(struct intel_crtc_state *old_crtc_state)
 
 	crtc->wm.cxsr_allowed = true;
 
-	if (pipe_config->wm_changed)
+	if (pipe_config->wm_changed && pipe_config->base.active)
 		intel_update_watermarks(&crtc->base);
 
 	if (old_pri_state) {
@@ -13327,6 +13327,9 @@ static int intel_atomic_commit(struct drm_device *dev,
 			dev_priv->display.crtc_disable(crtc);
 			intel_crtc->active = false;
 			intel_disable_shared_dpll(intel_crtc);
+
+			if (!crtc->state->active)
+				intel_update_watermarks(crtc);
 		}
 	}
 
-- 
2.1.0