[Intel-gfx] [PATCH] drm/i915: Be defensive and don't assume PSR has any commit to sync against

[Chris Wilson]

If the previous modeset commit has completed and is no longer part of
the crtc state, skip waiting for it.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107792
Fixes: c44301fce614 ("drm/i915: Allow control of PSR at runtime through debugfs, v6")
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
---
 drivers/gpu/drm/i915/intel_psr.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_psr.c b/drivers/gpu/drm/i915/intel_psr.c
index 21984d4c08ed..bddc9c7c681e 100644
--- a/drivers/gpu/drm/i915/intel_psr.c
+++ b/drivers/gpu/drm/i915/intel_psr.c
@@ -834,6 +834,7 @@ int intel_psr_set_debugfs_mode(struct drm_i915_private *dev_priv,
 	struct drm_device *dev = &dev_priv->drm;
 	struct drm_connector_state *conn_state;
 	struct intel_crtc_state *crtc_state = NULL;
+	struct drm_crtc_commit *commit = NULL;
 	struct drm_crtc *crtc;
 	struct intel_dp *dp;
 	int ret;
@@ -860,12 +861,15 @@ int intel_psr_set_debugfs_mode(struct drm_i915_private *dev_priv,
 			return ret;
 
 		crtc_state = to_intel_crtc_state(crtc->state);
-		ret = wait_for_completion_interruptible(&crtc_state->base.commit->hw_done);
-	} else
-		ret = wait_for_completion_interruptible(&conn_state->commit->hw_done);
-
-	if (ret)
-		return ret;
+		commit = crtc_state->base.commit;
+	} else {
+		commit = conn_state->commit;
+	}
+	if (commit) {
+		ret = wait_for_completion_interruptible(&commit->hw_done);
+		if (ret)
+			return ret;
+	}
 
 	ret = mutex_lock_interruptible(&dev_priv->psr.lock);
 	if (ret)
-- 
2.19.0.rc1