drm/i915/psr: CAN_PSR() macro to check for PSR source and sink support.

The global variable dev_priv->psr.sink_support is set if an eDP sink
supports PSR. Use this instead of redoing the check with is_edp_psr().
Combine source and sink support checks into a macro that can be used to
return early from psr_{invalidate, single_frame_update, flush}.

Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180103213824.1405-2-dhinakaran.pandiyan@intel.com

drivers/gpu/drm/i915/intel_drv.h

@@ -1760,6 +1760,7 @@ static inline void intel_backlight_device_unregister(struct intel_connector *con
 
 
 /* intel_psr.c */
+#define CAN_PSR(dev_priv) (HAS_PSR(dev_priv) && dev_priv->psr.sink_support)
 void intel_psr_enable(struct intel_dp *intel_dp,
 		      const struct intel_crtc_state *crtc_state);
 void intel_psr_disable(struct intel_dp *intel_dp,

drivers/gpu/drm/i915/intel_psr.c

@@ -56,14 +56,6 @@
 #include "intel_drv.h"
 #include "i915_drv.h"
 
-static bool is_edp_psr(struct intel_dp *intel_dp)
-{
-	if (!intel_dp_is_edp(intel_dp))
-		return false;
-
-	return intel_dp->psr_dpcd[0] & DP_PSR_IS_SUPPORTED;
-}
-
 static bool vlv_is_psr_active_on_pipe(struct drm_device *dev, int pipe)
 {
 	struct drm_i915_private *dev_priv = to_i915(dev);
@@ -358,10 +350,7 @@ void intel_psr_compute_config(struct intel_dp *intel_dp,
 		&crtc_state->base.adjusted_mode;
 	int psr_setup_time;
 
-	if (!HAS_PSR(dev_priv))
-		return;
-
-	if (!is_edp_psr(intel_dp))
+	if (!CAN_PSR(dev_priv))
 		return;
 
 	if (!i915_modparams.enable_psr) {
@@ -794,7 +783,7 @@ void intel_psr_single_frame_update(struct drm_i915_private *dev_priv,
 	enum pipe pipe;
 	u32 val;
 
-	if (!HAS_PSR(dev_priv))
+	if (!CAN_PSR(dev_priv))
 		return;
 
 	/*
@@ -843,7 +832,7 @@ void intel_psr_invalidate(struct drm_i915_private *dev_priv,
 	struct drm_crtc *crtc;
 	enum pipe pipe;
 
-	if (!HAS_PSR(dev_priv))
+	if (!CAN_PSR(dev_priv))
 		return;
 
 	mutex_lock(&dev_priv->psr.lock);
@@ -883,7 +872,7 @@ void intel_psr_flush(struct drm_i915_private *dev_priv,
 	struct drm_crtc *crtc;
 	enum pipe pipe;
 
-	if (!HAS_PSR(dev_priv))
+	if (!CAN_PSR(dev_priv))
 		return;
 
 	mutex_lock(&dev_priv->psr.lock);