diff options
Diffstat (limited to 'drivers/gpu/drm/i915/display/intel_dp_link_training.c')
-rw-r--r-- | drivers/gpu/drm/i915/display/intel_dp_link_training.c | 43 |
1 files changed, 32 insertions, 11 deletions
diff --git a/drivers/gpu/drm/i915/display/intel_dp_link_training.c b/drivers/gpu/drm/i915/display/intel_dp_link_training.c index e4f1843170b7..a23ed7290843 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_link_training.c +++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.c @@ -34,9 +34,25 @@ intel_dp_dump_link_status(const u8 link_status[DP_LINK_STATUS_SIZE]) link_status[3], link_status[4], link_status[5]); } +static u8 dp_voltage_max(u8 preemph) +{ + switch (preemph & DP_TRAIN_PRE_EMPHASIS_MASK) { + case DP_TRAIN_PRE_EMPH_LEVEL_0: + return DP_TRAIN_VOLTAGE_SWING_LEVEL_3; + case DP_TRAIN_PRE_EMPH_LEVEL_1: + return DP_TRAIN_VOLTAGE_SWING_LEVEL_2; + case DP_TRAIN_PRE_EMPH_LEVEL_2: + return DP_TRAIN_VOLTAGE_SWING_LEVEL_1; + case DP_TRAIN_PRE_EMPH_LEVEL_3: + default: + return DP_TRAIN_VOLTAGE_SWING_LEVEL_0; + } +} + void intel_dp_get_adjust_train(struct intel_dp *intel_dp, const u8 link_status[DP_LINK_STATUS_SIZE]) { + struct drm_i915_private *i915 = dp_to_i915(intel_dp); u8 v = 0; u8 p = 0; int lane; @@ -44,23 +60,28 @@ void intel_dp_get_adjust_train(struct intel_dp *intel_dp, u8 preemph_max; for (lane = 0; lane < intel_dp->lane_count; lane++) { - u8 this_v = drm_dp_get_adjust_request_voltage(link_status, lane); - u8 this_p = drm_dp_get_adjust_request_pre_emphasis(link_status, lane); - - if (this_v > v) - v = this_v; - if (this_p > p) - p = this_p; + v = max(v, drm_dp_get_adjust_request_voltage(link_status, lane)); + p = max(p, drm_dp_get_adjust_request_pre_emphasis(link_status, lane)); } - voltage_max = intel_dp_voltage_max(intel_dp); - if (v >= voltage_max) - v = voltage_max | DP_TRAIN_MAX_SWING_REACHED; + preemph_max = intel_dp->preemph_max(intel_dp); + drm_WARN_ON_ONCE(&i915->drm, + preemph_max != DP_TRAIN_PRE_EMPH_LEVEL_2 && + preemph_max != DP_TRAIN_PRE_EMPH_LEVEL_3); - preemph_max = intel_dp_pre_emphasis_max(intel_dp, v); if (p >= preemph_max) p = preemph_max | DP_TRAIN_MAX_PRE_EMPHASIS_REACHED; + v = min(v, dp_voltage_max(p)); + + voltage_max = intel_dp->voltage_max(intel_dp); + drm_WARN_ON_ONCE(&i915->drm, + voltage_max != DP_TRAIN_VOLTAGE_SWING_LEVEL_2 && + voltage_max != DP_TRAIN_VOLTAGE_SWING_LEVEL_3); + + if (v >= voltage_max) + v = voltage_max | DP_TRAIN_MAX_SWING_REACHED; + for (lane = 0; lane < 4; lane++) intel_dp->train_set[lane] = v | p; } |