[Intel-gfx] [PATCH 2/2] drm/i915: Also record time difference if vblank evasion fails.

[Maarten Lankhorst]

This makes the error message slightly more useful.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_drv.h    | 2 ++
 drivers/gpu/drm/i915/intel_sprite.c | 6 ++++--
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 172c10ac92ae..513981751e92 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -565,6 +565,8 @@ struct intel_crtc {
 	int scanline_offset;
 
 	unsigned start_vbl_count;
+	ktime_t start_vbl_time;
+
 	struct intel_crtc_atomic_commit atomic;
 
 	/* scalers available on this crtc */
diff --git a/drivers/gpu/drm/i915/intel_sprite.c b/drivers/gpu/drm/i915/intel_sprite.c
index 63fba42be2cf..cc0eb3915f1c 100644
--- a/drivers/gpu/drm/i915/intel_sprite.c
+++ b/drivers/gpu/drm/i915/intel_sprite.c
@@ -134,6 +134,7 @@ void intel_pipe_update_start(struct intel_crtc *crtc)
 
 	drm_crtc_vblank_put(&crtc->base);
 
+	crtc->start_vbl_time = ktime_get();
 	crtc->start_vbl_count = dev->driver->get_vblank_counter(dev, pipe);
 
 	trace_i915_pipe_update_vblank_evaded(crtc, min, max,
@@ -160,8 +161,9 @@ void intel_pipe_update_end(struct intel_crtc *crtc)
 	local_irq_enable();
 
 	if (crtc->start_vbl_count && crtc->start_vbl_count != end_vbl_count)
-		DRM_ERROR("Atomic update failure on pipe %c (start=%u end=%u)\n",
-			  pipe_name(pipe), crtc->start_vbl_count, end_vbl_count);
+		DRM_ERROR("Atomic update failure on pipe %c (start=%u end=%u) time %lld us\n",
+			  pipe_name(pipe), crtc->start_vbl_count, end_vbl_count,
+			  ktime_us_delta(ktime_get(), crtc->start_vbl_time));
 }
 
 static void
-- 
2.1.0