[Intel-gfx] [PATCH v2 4/9] drm/i915/psr: Begin to handle PSR/PSR2 errors set by sink

[José Roberto de Souza]

eDP spec states that sink device will do a short pulse in HPD
line when there is a PSR/PSR2 error that needs to be handled by
source, this is handling the first and most simples error:
DP_PSR_SINK_INTERNAL_ERROR.

Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
---

Changes from v1:
- printing a debug message when sink assert a error

 drivers/gpu/drm/i915/intel_dp.c  |  2 ++
 drivers/gpu/drm/i915/intel_drv.h |  1 +
 drivers/gpu/drm/i915/intel_psr.c | 48 +++++++++++++++++++++++++++++---
 3 files changed, 47 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 62f82c4298ac..701963a192ee 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -4462,6 +4462,8 @@ intel_dp_short_pulse(struct intel_dp *intel_dp)
 	if (intel_dp_needs_link_retrain(intel_dp))
 		return false;
 
+	intel_psr_hpd_short_pulse_handle(intel_dp);
+
 	if (intel_dp->compliance.test_type == DP_TEST_LINK_TRAINING) {
 		DRM_DEBUG_KMS("Link Training Compliance Test requested\n");
 		/* Send a Hotplug Uevent to userspace to start modeset */
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 5bd2263407b2..b79e15ecd052 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1901,6 +1901,7 @@ void intel_psr_single_frame_update(struct drm_i915_private *dev_priv,
 				   unsigned frontbuffer_bits);
 void intel_psr_compute_config(struct intel_dp *intel_dp,
 			      struct intel_crtc_state *crtc_state);
+void intel_psr_hpd_short_pulse_handle(struct intel_dp *intel_dp);
 
 /* 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 934498505356..4cb27faab707 100644
--- a/drivers/gpu/drm/i915/intel_psr.c
+++ b/drivers/gpu/drm/i915/intel_psr.c
@@ -996,6 +996,15 @@ void intel_psr_invalidate(struct drm_i915_private *dev_priv,
 	mutex_unlock(&dev_priv->psr.lock);
 }
 
+static void intel_psr_schedule_activate_work(struct drm_i915_private *dev_priv)
+{
+	if (dev_priv->psr.active || dev_priv->psr.busy_frontbuffer_bits
+	    || work_busy(&dev_priv->psr.work.work))
+		return;
+
+	schedule_delayed_work(&dev_priv->psr.work, msecs_to_jiffies(100));
+}
+
 /**
  * intel_psr_flush - Flush PSR
  * @dev_priv: i915 device
@@ -1052,10 +1061,8 @@ void intel_psr_flush(struct drm_i915_private *dev_priv,
 		}
 	}
 
-	if (!dev_priv->psr.active && !dev_priv->psr.busy_frontbuffer_bits)
-		if (!work_busy(&dev_priv->psr.work.work))
-			schedule_delayed_work(&dev_priv->psr.work,
-					      msecs_to_jiffies(100));
+	intel_psr_schedule_activate_work(dev_priv);
+
 	mutex_unlock(&dev_priv->psr.lock);
 }
 
@@ -1122,3 +1129,36 @@ void intel_psr_init(struct drm_i915_private *dev_priv)
 		dev_priv->psr.exit = hsw_psr_exit;
 	}
 }
+
+void intel_psr_hpd_short_pulse_handle(struct intel_dp *intel_dp)
+{
+	struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
+	struct drm_device *dev = intel_dig_port->base.base.dev;
+	struct drm_i915_private *dev_priv = to_i915(dev);
+	struct i915_psr *psr = &dev_priv->psr;
+	uint8_t val;
+
+	if (!HAS_PSR(dev_priv) || !intel_dp_is_edp(intel_dp))
+		return;
+
+	mutex_lock(&psr->lock);
+
+	if (psr->enabled != intel_dp)
+		goto not_enabled;
+
+	if (drm_dp_dpcd_readb(&intel_dp->aux, DP_PSR_STATUS, &val) != 1) {
+		DRM_DEBUG_KMS("PSR_STATUS read failed\n");
+		goto dpcd_error;
+	}
+
+	if ((val & DP_PSR_SINK_STATE_MASK) == DP_PSR_SINK_INTERNAL_ERROR) {
+		DRM_DEBUG_KMS("PSR sink internal error, exiting PSR\n");
+		intel_psr_exit(dev_priv);
+	}
+
+	/* TODO: handle other PSR/PSR2 errors */
+dpcd_error:
+	intel_psr_schedule_activate_work(dev_priv);
+not_enabled:
+	mutex_unlock(&psr->lock);
+}
-- 
2.17.0