drm/i915: Use crtc_state->has_psr instead of CAN_PSR for pipe update

In commit "drm/i915: Wait for PSR exit before checking for vblank
evasion", the idea was to limit the PSR IDLE checks when PSR is
actually supported. While CAN_PSR does do that check, it doesn't
applies on a per-crtc basis. crtc_state->has_psr is a more granular
check that only applies to pipe(s) that have PSR enabled.

Without the has_psr check, we end up waiting on the eDP transcoder's
PSR_STATUS register irrespective of whether the pipe being updated is
driving it or not.

v2: Remove unnecessary parantheses, make checkpatch happy.

v3: Move the has_psr check to intel_psr_wait_for_idle and commit
    message changes (DK).

v4: Derive dev_priv from intel_crtc_state (DK)

v5: Commit message changes to reflect the HW behavior (DK)

Fixes: a6089879 ("drm/i915: Wait for PSR exit before checking for vblank evasion")
Reviewed-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Signed-off-by: Tarun Vyas <tarun.vyas@intel.com>
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180712053323.26266-1-tarun.vyas@intel.com

drivers/gpu/drm/i915/intel_drv.h

@@ -1922,7 +1922,7 @@ void intel_psr_compute_config(struct intel_dp *intel_dp,
 void intel_psr_irq_control(struct drm_i915_private *dev_priv, bool debug);
 void intel_psr_irq_handler(struct drm_i915_private *dev_priv, u32 psr_iir);
 void intel_psr_short_pulse(struct intel_dp *intel_dp);
-int intel_psr_wait_for_idle(struct drm_i915_private *dev_priv);
+int intel_psr_wait_for_idle(const struct intel_crtc_state *new_crtc_state);
 
 /* intel_runtime_pm.c */
 int intel_power_domains_init(struct drm_i915_private *);

drivers/gpu/drm/i915/intel_psr.c

@@ -717,11 +717,16 @@ void intel_psr_disable(struct intel_dp *intel_dp,
 	cancel_work_sync(&dev_priv->psr.work);
 }
 
-int intel_psr_wait_for_idle(struct drm_i915_private *dev_priv)
+int intel_psr_wait_for_idle(const struct intel_crtc_state *new_crtc_state)
 {
+	struct intel_crtc *crtc = to_intel_crtc(new_crtc_state->base.crtc);
+	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
 	i915_reg_t reg;
 	u32 mask;
 
+	if (!new_crtc_state->has_psr)
+		return 0;
+
 	/*
 	 * The sole user right now is intel_pipe_update_start(),
 	 * which won't race with psr_enable/disable, which is

drivers/gpu/drm/i915/intel_sprite.c

@@ -118,7 +118,7 @@ void intel_pipe_update_start(const struct intel_crtc_state *new_crtc_state)
 	 * VBL interrupts will start the PSR exit and prevent a PSR
 	 * re-entry as well.
 	 */
-	if (CAN_PSR(dev_priv) && intel_psr_wait_for_idle(dev_priv))
+	if (intel_psr_wait_for_idle(new_crtc_state))
 		DRM_ERROR("PSR idle timed out, atomic update may fail\n");
 
 	local_irq_disable();