[Intel-gfx] [PATCH v4] drm/i915: Use crtc_state->has_psr instead of CAN_PSR for pipe update

[Tarun Vyas]

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.

Currently, the driver supports PSR on port A + transcoder eDP, so
only pipe A will wait for PSR to go IDLE, as it should, and other
pipes should return immediately.

Without the has_psr check, non-PSR pipe_updates (pipe B/C in this
case), end up waiting on PSR pipe (pipe A in this case) to exit PSR,
which may incur substantial delays for non-PSR pipe updates alongwith
the fact the it doesn't makes any sense.

Fixes: a608987970b9 ("drm/i915: Wait for PSR exit before checking for
vblank evasion")

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)

Signed-off-by: Tarun Vyas <tarun.vyas at intel.com>
---
 drivers/gpu/drm/i915/intel_drv.h    | 2 +-
 drivers/gpu/drm/i915/intel_psr.c    | 7 ++++++-
 drivers/gpu/drm/i915/intel_sprite.c | 2 +-
 3 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 61e715ddd0d5..699073fbecb1 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1923,7 +1923,7 @@ 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 *);
diff --git a/drivers/gpu/drm/i915/intel_psr.c b/drivers/gpu/drm/i915/intel_psr.c
index 23acc9ac8d4d..e97db5dd75b1 100644
--- a/drivers/gpu/drm/i915/intel_psr.c
+++ b/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
diff --git a/drivers/gpu/drm/i915/intel_sprite.c b/drivers/gpu/drm/i915/intel_sprite.c
index 4990d6e84ddf..9d6d1ac149da 100644
--- a/drivers/gpu/drm/i915/intel_sprite.c
+++ b/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();
-- 
2.13.5