diff options
| -rw-r--r-- | drivers/gpu/drm/i915/intel_dp_link_training.c | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/drivers/gpu/drm/i915/intel_dp_link_training.c b/drivers/gpu/drm/i915/intel_dp_link_training.c index 4da6e33c7fa1..299cad5632ed 100644 --- a/drivers/gpu/drm/i915/intel_dp_link_training.c +++ b/drivers/gpu/drm/i915/intel_dp_link_training.c @@ -129,7 +129,7 @@ static bool intel_dp_link_training_clock_recovery(struct intel_dp *intel_dp) { uint8_t voltage; - int voltage_tries, max_vswing_tries; + int voltage_tries, max_vswing_tries, cr_tries, max_cr_tries; uint8_t link_config[2]; uint8_t link_bw, rate_select; @@ -170,9 +170,20 @@ intel_dp_link_training_clock_recovery(struct intel_dp *intel_dp) return false; } + /* + * DP 1.4 spec clock recovery retries defined but + * for devices pre-DP 1.4 we set the retry limit + * to 4 (voltage levels) x 4 (preemphasis levels) x + * x 5 (same voltage retries) = 80 (max iterations) + */ + if (intel_dp->dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14) + max_cr_tries = 10; + else + max_cr_tries = 80; + voltage_tries = 1; max_vswing_tries = 0; - for (;;) { + for (cr_tries = 0; cr_tries < max_cr_tries; ++cr_tries) { uint8_t link_status[DP_LINK_STATUS_SIZE]; drm_dp_link_train_clock_recovery_delay(intel_dp->dpcd); @@ -216,6 +227,8 @@ intel_dp_link_training_clock_recovery(struct intel_dp *intel_dp) ++max_vswing_tries; } + DRM_ERROR("Failed clock recovery %d times, giving up!\n", max_cr_tries); + return false; } /* |