return ret == intel_dp->lane_count;
}
+static bool intel_dp_link_max_vswing_reached(struct intel_dp *intel_dp)
+{
+ int lane;
+
+ for (lane = 0; lane < intel_dp->lane_count; lane++)
+ if ((intel_dp->train_set[lane] &
+ DP_TRAIN_MAX_SWING_REACHED) == 0)
+ return false;
+
+ return true;
+}
+
/* Enable corresponding port and start training pattern 1 */
-static void
+static bool
intel_dp_link_training_clock_recovery(struct intel_dp *intel_dp)
{
- int i;
uint8_t voltage;
- int voltage_tries, loop_tries;
+ int voltage_tries, max_vswing_tries;
uint8_t link_config[2];
uint8_t link_bw, rate_select;
if (drm_dp_enhanced_frame_cap(intel_dp->dpcd))
link_config[1] |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
drm_dp_dpcd_write(&intel_dp->aux, DP_LINK_BW_SET, link_config, 2);
+
if (intel_dp->num_sink_rates)
drm_dp_dpcd_write(&intel_dp->aux, DP_LINK_RATE_SET,
&rate_select, 1);
DP_TRAINING_PATTERN_1 |
DP_LINK_SCRAMBLING_DISABLE)) {
DRM_ERROR("failed to enable link training\n");
- return;
+ return false;
}
- voltage = 0xff;
- voltage_tries = 0;
- loop_tries = 0;
+ voltage_tries = 1;
+ max_vswing_tries = 0;
for (;;) {
uint8_t link_status[DP_LINK_STATUS_SIZE];
drm_dp_link_train_clock_recovery_delay(intel_dp->dpcd);
+
if (!intel_dp_get_link_status(intel_dp, link_status)) {
DRM_ERROR("failed to get link status\n");
- break;
+ return false;
}
if (drm_dp_clock_recovery_ok(link_status, intel_dp->lane_count)) {
DRM_DEBUG_KMS("clock recovery OK\n");
- break;
+ return true;
}
- /* Check to see if we've tried the max voltage */
- for (i = 0; i < intel_dp->lane_count; i++)
- if ((intel_dp->train_set[i] & DP_TRAIN_MAX_SWING_REACHED) == 0)
- break;
- if (i == intel_dp->lane_count) {
- ++loop_tries;
- if (loop_tries == 5) {
- DRM_ERROR("too many full retries, give up\n");
- intel_dp_dump_link_status(link_status);
- break;
- }
- intel_dp_reset_link_train(intel_dp,
- DP_TRAINING_PATTERN_1 |
- DP_LINK_SCRAMBLING_DISABLE);
- voltage_tries = 0;
- continue;
+ if (voltage_tries == 5) {
+ DRM_DEBUG_KMS("Same voltage tried 5 times\n");
+ return false;
+ }
+
+ if (max_vswing_tries == 1) {
+ DRM_DEBUG_KMS("Max Voltage Swing reached\n");
+ return false;
}
- /* Check to see if we've tried the same voltage 5 times */
- if ((intel_dp->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK) == voltage) {
- ++voltage_tries;
- if (voltage_tries == 5) {
- DRM_ERROR("too many voltage retries, give up\n");
- break;
- }
- } else
- voltage_tries = 0;
voltage = intel_dp->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK;
/* Update training set as requested by target */
intel_get_adjust_train(intel_dp, link_status);
if (!intel_dp_update_link_train(intel_dp)) {
DRM_ERROR("failed to update link training\n");
- break;
+ return false;
}
+
+ if ((intel_dp->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK) ==
+ voltage)
+ ++voltage_tries;
+ else
+ voltage_tries = 1;
+
+ if (intel_dp_link_max_vswing_reached(intel_dp))
+ ++max_vswing_tries;
+
}
}
* Intel platforms that support HBR2 also support TPS3. TPS3 support is
* also mandatory for downstream devices that support HBR2. However, not
* all sinks follow the spec.
- *
- * Due to WaDisableHBR2 SKL < B0 is the only exception where TPS3 is
- * supported in source but still not enabled.
*/
source_tps3 = intel_dp_source_supports_hbr2(intel_dp);
sink_tps3 = drm_dp_tps3_supported(intel_dp->dpcd);
return training_pattern;
}
-static void
+static bool
intel_dp_link_training_channel_equalization(struct intel_dp *intel_dp)
{
- bool channel_eq = false;
- int tries, cr_tries;
+ int tries;
u32 training_pattern;
+ uint8_t link_status[DP_LINK_STATUS_SIZE];
training_pattern = intel_dp_training_pattern(intel_dp);
training_pattern |
DP_LINK_SCRAMBLING_DISABLE)) {
DRM_ERROR("failed to start channel equalization\n");
- return;
+ return false;
}
- tries = 0;
- cr_tries = 0;
- channel_eq = false;
- for (;;) {
- uint8_t link_status[DP_LINK_STATUS_SIZE];
-
- if (cr_tries > 5) {
- DRM_ERROR("failed to train DP, aborting\n");
- intel_dp_dump_link_status(link_status);
- break;
- }
+ intel_dp->channel_eq_status = false;
+ for (tries = 0; tries < 5; tries++) {
drm_dp_link_train_channel_eq_delay(intel_dp->dpcd);
if (!intel_dp_get_link_status(intel_dp, link_status)) {
/* Make sure clock is still ok */
if (!drm_dp_clock_recovery_ok(link_status,
intel_dp->lane_count)) {
- intel_dp_link_training_clock_recovery(intel_dp);
- intel_dp_set_link_train(intel_dp,
- training_pattern |
- DP_LINK_SCRAMBLING_DISABLE);
- cr_tries++;
- continue;
+ intel_dp_dump_link_status(link_status);
+ DRM_DEBUG_KMS("Clock recovery check failed, cannot "
+ "continue channel equalization\n");
+ break;
}
if (drm_dp_channel_eq_ok(link_status,
intel_dp->lane_count)) {
- channel_eq = true;
+ intel_dp->channel_eq_status = true;
+ DRM_DEBUG_KMS("Channel EQ done. DP Training "
+ "successful\n");
break;
}
- /* Try 5 times, then try clock recovery if that fails */
- if (tries > 5) {
- intel_dp_link_training_clock_recovery(intel_dp);
- intel_dp_set_link_train(intel_dp,
- training_pattern |
- DP_LINK_SCRAMBLING_DISABLE);
- tries = 0;
- cr_tries++;
- continue;
- }
-
/* Update training set as requested by target */
intel_get_adjust_train(intel_dp, link_status);
if (!intel_dp_update_link_train(intel_dp)) {
DRM_ERROR("failed to update link training\n");
break;
}
- ++tries;
+ }
+
+ /* Try 5 times, else fail and try at lower BW */
+ if (tries == 5) {
+ intel_dp_dump_link_status(link_status);
+ DRM_DEBUG_KMS("Channel equalization failed 5 times\n");
}
intel_dp_set_idle_link_train(intel_dp);
- if (channel_eq)
- DRM_DEBUG_KMS("Channel EQ done. DP Training successful\n");
+ return intel_dp->channel_eq_status;
+
}
void intel_dp_stop_link_train(struct intel_dp *intel_dp)
projects / karo-tx-linux.git / blobdiff