[Intel-gfx] [PATCH v2 4/4] drm/i915/psr: Timestamps for PSR entry and exit interrupts.

[Dhinakaran Pandiyan]

Timestamps are useful for IGT tests that trigger PSR exit and/or wait for
PSR entry.

v2: Removed seqlock (Ville)
    Removed erroneous warning in irq loop (Chris)

Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
Cc: Chris Wilson <chris at chris-wilson.co.uk>
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
---
 drivers/gpu/drm/i915/i915_debugfs.c | 7 +++++++
 drivers/gpu/drm/i915/i915_drv.h     | 2 ++
 drivers/gpu/drm/i915/intel_psr.c    | 9 +++++++--
 3 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 6fd801ef7cbb..c69384d17226 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -2686,6 +2686,13 @@ static int i915_edp_psr_status(struct seq_file *m, void *data)
 	}
 	mutex_unlock(&dev_priv->psr.lock);
 
+	if (READ_ONCE(dev_priv->psr.debug)) {
+		seq_printf(m, "Last attempted entry at: %lld\n",
+			   dev_priv->psr.last_entry_attempt);
+		seq_printf(m, "Last exit at: %lld\n",
+			   dev_priv->psr.last_exit);
+	}
+
 	intel_runtime_pm_put(dev_priv);
 	return 0;
 }
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index c0224a86344e..41c3268b5de5 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -609,6 +609,8 @@ struct i915_psr {
 	bool alpm;
 	bool has_hw_tracking;
 	bool debug;
+	ktime_t last_entry_attempt;
+	ktime_t last_exit;
 
 	void (*enable_source)(struct intel_dp *,
 			      const struct intel_crtc_state *);
diff --git a/drivers/gpu/drm/i915/intel_psr.c b/drivers/gpu/drm/i915/intel_psr.c
index fdc5e1bf198a..0d338632c2bb 100644
--- a/drivers/gpu/drm/i915/intel_psr.c
+++ b/drivers/gpu/drm/i915/intel_psr.c
@@ -125,6 +125,7 @@ void intel_psr_irq_handler(struct drm_i915_private *dev_priv, u32 psr_iir)
 {
 	u32 transcoders = BIT(TRANSCODER_EDP);
 	enum transcoder cpu_transcoder;
+	ktime_t time_ns =  ktime_get();
 
 	if (INTEL_GEN(dev_priv) >= 8)
 		transcoders |= BIT(TRANSCODER_A) |
@@ -137,13 +138,17 @@ void intel_psr_irq_handler(struct drm_i915_private *dev_priv, u32 psr_iir)
 			DRM_DEBUG_KMS("[transcoder %s] PSR aux error\n",
 				      transcoder_name(cpu_transcoder));
 
-		if (psr_iir & EDP_PSR_PRE_ENTRY(cpu_transcoder))
+		if (psr_iir & EDP_PSR_PRE_ENTRY(cpu_transcoder)) {
+			dev_priv->psr.last_entry_attempt = time_ns;
 			DRM_DEBUG_KMS("[transcoder %s] PSR entry attempt in 2 vblanks\n",
 				      transcoder_name(cpu_transcoder));
+		}
 
-		if (psr_iir & EDP_PSR_POST_EXIT(cpu_transcoder))
+		if (psr_iir & EDP_PSR_POST_EXIT(cpu_transcoder)) {
+			dev_priv->psr.last_exit = time_ns;
 			DRM_DEBUG_KMS("[transcoder %s] PSR exit completed\n",
 				      transcoder_name(cpu_transcoder));
+		}
 	}
 }
 
-- 
2.14.1