drm/i915: Avoid re-configure panel on every PSR re-enable.

The panel has to be reconfigured only when it really loose the power.
The traditional enable/disable sequence already take care of this so we can
minimize the time spend on every re-enable.
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_dp.c

@@ -2121,10 +2121,7 @@ static void intel_edp_psr_do_enable(struct intel_dp *intel_dp)
 	WARN_ON(dev_priv->psr.active);
 	lockdep_assert_held(&dev_priv->psr.lock);
 
-	/* Enable PSR on the panel */
-	intel_edp_psr_enable_sink(intel_dp);
-
-	/* Enable PSR on the host */
+	/* Enable/Re-enable PSR on the host */
 	intel_edp_psr_enable_source(intel_dp);
 
 	dev_priv->psr.active = true;
@@ -2162,6 +2159,9 @@ void intel_edp_psr_enable(struct intel_dp *intel_dp)
 	I915_WRITE(EDP_PSR_DEBUG_CTL(dev), EDP_PSR_DEBUG_MASK_MEMUP |
 		   EDP_PSR_DEBUG_MASK_HPD | EDP_PSR_DEBUG_MASK_LPSP);
 
+	/* Enable PSR on the panel */
+	intel_edp_psr_enable_sink(intel_dp);
+
 	dev_priv->psr.enabled = intel_dp;
 unlock:
 	mutex_unlock(&dev_priv->psr.lock);