[PATCH] drm/i915: Skip CRC readouts if fifo underrun is detected

[Mika Kahola]

Let's disregard a crc readout if fifo underrun is detected. This
may cause crc mismatch in IGT tests.

References: https://bugs.freedesktop.org/show_bug.cgi?id=103166

Signed-off-by: Mika Kahola <mika.kahola at intel.com>
---
 drivers/gpu/drm/i915/i915_irq.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 2e242270e270..9c893a0640bb 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -1756,7 +1756,8 @@ static void display_pipe_crc_irq_handler(struct drm_i915_private *dev_priv,
 	 * don't trust that one either.
 	 */
 	if (pipe_crc->skipped <= 0 ||
-	    (INTEL_GEN(dev_priv) >= 8 && pipe_crc->skipped == 1)) {
+	    (INTEL_GEN(dev_priv) >= 8 && pipe_crc->skipped == 1) ||
+		dev_priv->fbc.underrun_detected) {
 		pipe_crc->skipped++;
 		spin_unlock(&pipe_crc->lock);
 		return;
-- 
2.17.1