[Intel-gfx] [PATCH v2] drm/i915: Disable DRRS when PSR is enabled

[Radhakrishna Sripada]

Some platforms donot support PSR and DRRS simultaneously.
Visual artifacts and flickering were reported on BDW HP Spectre
x360 Convertible. Deferring to PSR when both PSR and DRRS are
supported by the panel.

V2: Minor code-style changes suggested by Rodrigo

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=101111
Cc: Nicholas Stommel <nicholas.stommel at gmail.com>
Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
Cc: Jani Nikula <jani.nikula at intel.com>
Cc: Clinton Taylor <clinton.a.taylor at intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
Signed-off-by: Radhakrishna Sripada <radhakrishna.sripada at intel.com>
---
 drivers/gpu/drm/i915/intel_dp.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 887953c0f495..aa5a69301257 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -5467,11 +5467,6 @@ static void intel_dp_set_drrs_state(struct drm_i915_private *dev_priv,
 		return;
 	}
 
-	/*
-	 * FIXME: This needs proper synchronization with psr state for some
-	 * platforms that cannot have PSR and DRRS enabled at the same time.
-	 */
-
 	dig_port = dp_to_dig_port(intel_dp);
 	encoder = &dig_port->base;
 	intel_crtc = to_intel_crtc(encoder->base.crtc);
@@ -5555,6 +5550,11 @@ void intel_edp_drrs_enable(struct intel_dp *intel_dp,
 		return;
 	}
 
+	if (dev_priv->psr.enabled) {
+		DRM_DEBUG_KMS("PSR enabled. Disabling DRRS.\n");
+		return;
+	}
+
 	mutex_lock(&dev_priv->drrs.mutex);
 	if (WARN_ON(dev_priv->drrs.dp)) {
 		DRM_ERROR("DRRS already enabled\n");
-- 
2.9.3