@@ -1334,17 +1334,24 @@ intel_dp_complete_link_train(struct intel_dp *intel_dp)
struct drm_device *dev = intel_dp->base.base.dev;
struct drm_i915_private *dev_priv = dev->dev_private;
bool channel_eq = false;
- int tries;
+ int tries, cr_tries;
u32 reg;
uint32_t DP = intel_dp->DP;
/* channel equalization */
tries = 0;
+ cr_tries = 0;
channel_eq = false;
for (;;) {
/* Use intel_dp->train_set[0] to set the voltage and pre emphasis values */
uint32_t signal_levels;
+ if (cr_tries > 5) {
+ DRM_ERROR("failed to train DP, aborting\n");
+ intel_dp_link_down(intel_dp);
+ break;
+ }
+
if (IS_GEN6(dev) && is_edp(intel_dp)) {
signal_levels = intel_gen6_edp_signal_levels(intel_dp->train_set[0]);
DP = (DP & ~EDP_LINK_TRAIN_VOL_EMP_MASK_SNB) | signal_levels;
@@ -1367,14 +1374,26 @@ intel_dp_complete_link_train(struct intel_dp *intel_dp)
if (!intel_dp_get_link_status(intel_dp))
break;
+ /* Make sure clock is still ok */
+ if (!intel_clock_recovery_ok(intel_dp->link_status, intel_dp->lane_count)) {
+ intel_dp_start_link_train(intel_dp);
+ cr_tries++;
+ continue;
+ }
+
if (intel_channel_eq_ok(intel_dp)) {
channel_eq = true;
break;
}
- /* Try 5 times */
- if (tries > 5)
- break;
+ /* Try 5 times, then try clock recovery if that fails */
+ if (tries > 5) {
+ intel_dp_link_down(intel_dp);
+ intel_dp_start_link_train(intel_dp);
+ tries = 0;
+ cr_tries++;
+ continue;
+ }
/* Compute new intel_dp->train_set as requested by target */
intel_get_adjust_train(intel_dp);