[Intel-gfx] [PATCH v5 3/3] drm/i915: DP channel EQ check for use of DP link training optimization

[Mika Kahola]

Don't use DP link training optimization if channel EQ is not ok. It has
been reported that in case of failure in channel EQ check the link training
optimization can be enabled and therefore may not be able to reuse the
previously computed drive current and pre-emphasis levels.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=91393
Signed-off-by: Mika Kahola <mika.kahola at intel.com>
---
 drivers/gpu/drm/i915/intel_dp.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 3137187..0cd1ccb 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -4354,6 +4354,7 @@ intel_dp_check_link_status(struct intel_dp *intel_dp)
 		(!drm_dp_channel_eq_ok(link_status, intel_dp->lane_count))) {
 		DRM_DEBUG_KMS("%s: channel EQ not ok, retraining\n",
 			      intel_encoder->base.name);
+		intel_dp->train_set_valid = false;
 		intel_dp_start_link_train(intel_dp);
 		intel_dp_stop_link_train(intel_dp);
 	}
-- 
1.9.1