diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 1dc60408d5b8c34f1e3dd30ef8bf51167833cdfb..c768e30e5e8525711c87f3a5ef9f2865b422389c 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -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);