[Intel-gfx] [PATCH 2/2] drm/i915: add more debug info for when atomic updates fail

[Jesse Barnes]

I used these additional fields to track down the issue I saw on HSW.

References: https://bugs.freedesktop.org/show_bug.cgi?id=91579
Signed-off-by: Jesse Barnes <jbarnes at virtuousgeek.org>
---
 drivers/gpu/drm/i915/intel_drv.h    |  2 ++
 drivers/gpu/drm/i915/intel_sprite.c | 16 ++++++++++++----
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 46484e4..90cad50 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -565,6 +565,8 @@ struct intel_crtc {
 
 	unsigned start_vbl_count;
 	ktime_t start_vbl_time;
+	int min_vbl, max_vbl;
+	int scanline_start;
 
 	struct intel_crtc_atomic_commit atomic;
 
diff --git a/drivers/gpu/drm/i915/intel_sprite.c b/drivers/gpu/drm/i915/intel_sprite.c
index 0c2c62f..ff8c9d5 100644
--- a/drivers/gpu/drm/i915/intel_sprite.c
+++ b/drivers/gpu/drm/i915/intel_sprite.c
@@ -94,6 +94,9 @@ void intel_pipe_update_start(struct intel_crtc *crtc)
 	min = vblank_start - usecs_to_scanlines(mode, 100);
 	max = vblank_start - 1;
 
+	crtc->min_vbl = min;
+	crtc->max_vbl = max;
+
 	local_irq_disable();
 	crtc->start_vbl_count = 0;
 
@@ -122,8 +125,10 @@ void intel_pipe_update_start(struct intel_crtc *crtc)
 		 * scanline_offset used to correct the DSL readout.)
 		 */
 		scanline = intel_get_crtc_scanline(crtc);
-		if (scanline > 2 && (scanline < min || scanline > max))
+		if (scanline > 2 && (scanline < min || scanline > max)) {
+			crtc->scanline_start = scanline;
 			break;
+		}
 
 		if (timeout <= 0) {
 			DRM_ERROR("Potential atomic update failure on pipe %c\n",
@@ -169,10 +174,13 @@ 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) time %lld us\n",
+	if (crtc->start_vbl_count && crtc->start_vbl_count != end_vbl_count) {
+		DRM_ERROR("Atomic update failure on pipe %c (start=%u end=%u) time %lld us, min %d, max %d, scanline start %d, end %d\n",
 			  pipe_name(pipe), crtc->start_vbl_count, end_vbl_count,
-			  ktime_us_delta(end_vbl_time, crtc->start_vbl_time));
+			  ktime_us_delta(end_vbl_time, crtc->start_vbl_time),
+			  crtc->min_vbl, crtc->max_vbl, crtc->scanline_start,
+			  intel_get_crtc_scanline(crtc));
+	}
 }
 
 static void
-- 
1.9.1