[Intel-gfx] [PATCH v3 1/2] drm/i915: Lockless wait for PSR idle.

[Tarun Vyas]

Before checking for vblank evasion in pipe_update_start, we
need to wait for PSR idle. intel_psr.c already has psr_wait_for_idle
but we don't need any psr locks in pipe_update_start anyway b/c
psr_enable/disable won't race there. There is some code duplication
here but can't help it (borrowed from psr_wait_for_idle).

Signed-off-by: Tarun Vyas <tarun.vyas at intel.com>
---
 drivers/gpu/drm/i915/intel_drv.h |  1 +
 drivers/gpu/drm/i915/intel_psr.c | 17 +++++++++++++++++
 2 files changed, 18 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index d7dbca1aabff..935eb3d5d9bb 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1919,6 +1919,7 @@ void intel_psr_compute_config(struct intel_dp *intel_dp,
 			      struct intel_crtc_state *crtc_state);
 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_wait_for_idle(struct drm_i915_private *dev_priv);
 
 /* 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 db27f2faa1de..75e2035ba29f 100644
--- a/drivers/gpu/drm/i915/intel_psr.c
+++ b/drivers/gpu/drm/i915/intel_psr.c
@@ -883,6 +883,23 @@ void intel_psr_disable(struct intel_dp *intel_dp,
 	cancel_delayed_work_sync(&dev_priv->psr.work);
 }
 
+void intel_psr_wait_for_idle(struct drm_i915_private *dev_priv)
+{
+	i915_reg_t reg;
+	u32 mask;
+
+	if (dev_priv->psr.psr2_enabled) {
+		reg = EDP_PSR2_STATUS;
+		mask = EDP_PSR2_STATUS_STATE_MASK;
+	} else {
+		reg = EDP_PSR_STATUS;
+		mask = EDP_PSR_STATUS_STATE_MASK;
+	}
+
+	if (intel_wait_for_register(dev_priv, reg, mask, 0, 25))
+		DRM_ERROR("Timed out waiting for PSR Idle\n");
+}
+
 static bool psr_wait_for_idle(struct drm_i915_private *dev_priv)
 {
 	struct intel_dp *intel_dp;
-- 
2.13.5