[PATCH 4/6] drm/i915/dp: Don't fallback to reduced link bw in case of AUX IO errors
Imre Deak
imre.deak at intel.com
Tue Mar 24 17:23:01 UTC 2020
Signed-off-by: Imre Deak <imre.deak at intel.com>
---
.../drm/i915/display/intel_display_types.h | 2 +
drivers/gpu/drm/i915/display/intel_dp.c | 2 +
.../drm/i915/display/intel_dp_link_training.c | 58 +++++++++++++------
3 files changed, 43 insertions(+), 19 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index 671721e74075..082724b5ebec 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -1287,6 +1287,8 @@ struct intel_dp {
/* intersection of source and sink rates */
int num_common_rates;
int common_rates[DP_MAX_SUPPORTED_RATES];
+ /* Link training failed */
+ bool bad_link;
/* Max lane count for the current link */
int max_link_lane_count;
/* Max rate for the current link */
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 1a7bd8a8e852..a56443a35222 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -6073,6 +6073,8 @@ intel_dp_detect(struct drm_connector *connector,
}
if (intel_dp->reset_link_params) {
+ intel_dp->bad_link = false;
+
/* Initial max link lane count */
intel_dp->max_link_lane_count = intel_dp_max_common_lane_count(intel_dp);
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 a7defb37ab00..9df21b5fcaa1 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_link_training.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.c
@@ -127,7 +127,7 @@ static bool intel_dp_link_max_vswing_reached(struct intel_dp *intel_dp)
}
/* Enable corresponding port and start training pattern 1 */
-static bool
+static int
intel_dp_link_training_clock_recovery(struct intel_dp *intel_dp)
{
struct drm_i915_private *i915 = dp_to_i915(intel_dp);
@@ -173,7 +173,7 @@ intel_dp_link_training_clock_recovery(struct intel_dp *intel_dp)
DP_TRAINING_PATTERN_1 |
DP_LINK_SCRAMBLING_DISABLE)) {
drm_err(&i915->drm, "failed to enable link training\n");
- return false;
+ return -EIO;
}
/*
@@ -197,23 +197,23 @@ intel_dp_link_training_clock_recovery(struct intel_dp *intel_dp)
if (!intel_dp_get_link_status(intel_dp, link_status)) {
drm_err(&i915->drm, "failed to get link status\n");
- return false;
+ return -EIO;
}
if (drm_dp_clock_recovery_ok(link_status, intel_dp->lane_count)) {
drm_dbg_kms(&i915->drm, "clock recovery OK\n");
- return true;
+ return 0;
}
if (voltage_tries == 5) {
drm_dbg_kms(&i915->drm,
"Same voltage tried 5 times\n");
- return false;
+ return -EAGAIN;
}
if (max_vswing_reached) {
drm_dbg_kms(&i915->drm, "Max Voltage Swing reached\n");
- return false;
+ return -EAGAIN;
}
voltage = intel_dp->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK;
@@ -223,7 +223,7 @@ intel_dp_link_training_clock_recovery(struct intel_dp *intel_dp)
if (!intel_dp_update_link_train(intel_dp)) {
drm_err(&i915->drm,
"failed to update link training\n");
- return false;
+ return -EIO;
}
if ((intel_dp->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK) ==
@@ -238,7 +238,7 @@ intel_dp_link_training_clock_recovery(struct intel_dp *intel_dp)
}
drm_err(&i915->drm,
"Failed clock recovery %d times, giving up!\n", max_cr_tries);
- return false;
+ return -EAGAIN;
}
/*
@@ -289,14 +289,14 @@ static u32 intel_dp_training_pattern(struct intel_dp *intel_dp)
return DP_TRAINING_PATTERN_2;
}
-static bool
+static int
intel_dp_link_training_channel_equalization(struct intel_dp *intel_dp)
{
struct drm_i915_private *i915 = dp_to_i915(intel_dp);
int tries;
u32 training_pattern;
u8 link_status[DP_LINK_STATUS_SIZE];
- bool channel_eq = false;
+ int err;
training_pattern = intel_dp_training_pattern(intel_dp);
/* Scrambling is disabled for TPS2/3 and enabled for TPS4 */
@@ -307,15 +307,15 @@ intel_dp_link_training_channel_equalization(struct intel_dp *intel_dp)
if (!intel_dp_set_link_train(intel_dp,
training_pattern)) {
drm_err(&i915->drm, "failed to start channel equalization\n");
- return false;
+ return -EIO;
}
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)) {
drm_err(&i915->drm,
"failed to get link status\n");
+ err = -EIO;
break;
}
@@ -326,14 +326,15 @@ intel_dp_link_training_channel_equalization(struct intel_dp *intel_dp)
drm_dbg_kms(&i915->drm,
"Clock recovery check failed, cannot "
"continue channel equalization\n");
+ err = -EAGAIN;
break;
}
if (drm_dp_channel_eq_ok(link_status,
intel_dp->lane_count)) {
- channel_eq = true;
drm_dbg_kms(&i915->drm, "Channel EQ done. DP Training "
"successful\n");
+ err = 0;
break;
}
@@ -342,6 +343,7 @@ intel_dp_link_training_channel_equalization(struct intel_dp *intel_dp)
if (!intel_dp_update_link_train(intel_dp)) {
drm_err(&i915->drm,
"failed to update link training\n");
+ err = -EIO;
break;
}
}
@@ -351,11 +353,12 @@ intel_dp_link_training_channel_equalization(struct intel_dp *intel_dp)
intel_dp_dump_link_status(link_status);
drm_dbg_kms(&i915->drm,
"Channel equalization failed 5 times\n");
+ err = -EAGAIN;
}
intel_dp_set_idle_link_train(intel_dp);
- return channel_eq;
+ return err;
}
@@ -371,10 +374,14 @@ void
intel_dp_start_link_train(struct intel_dp *intel_dp)
{
struct intel_connector *intel_connector = intel_dp->attached_connector;
+ bool retry;
+ int err;
- if (!intel_dp_link_training_clock_recovery(intel_dp))
+ err = intel_dp_link_training_clock_recovery(intel_dp);
+ if (err)
goto failure_handling;
- if (!intel_dp_link_training_channel_equalization(intel_dp))
+ err = intel_dp_link_training_channel_equalization(intel_dp);
+ if (err)
goto failure_handling;
drm_dbg_kms(&dp_to_i915(intel_dp)->drm,
@@ -386,13 +393,26 @@ intel_dp_start_link_train(struct intel_dp *intel_dp)
failure_handling:
drm_dbg_kms(&dp_to_i915(intel_dp)->drm,
- "[CONNECTOR:%d:%s] Link Training failed at link rate = %d, lane count = %d",
+ "[CONNECTOR:%d:%s] Link Training failed at link rate = %d, lane count = %d, err = %pe",
intel_connector->base.base.id,
intel_connector->base.name,
- intel_dp->link_rate, intel_dp->lane_count);
- if (!intel_dp_get_link_train_fallback_values(intel_dp,
+ intel_dp->link_rate, intel_dp->lane_count,
+ ERR_PTR(err));
+
+ retry = false;
+
+ if (err == -EAGAIN &&
+ !intel_dp_get_link_train_fallback_values(intel_dp,
intel_dp->link_rate,
intel_dp->lane_count))
+ retry = true;
+
+ if (!intel_dp->bad_link) {
+ retry = true;
+ intel_dp->bad_link = true;
+ }
+
+ if (retry)
/* Schedule a Hotplug Uevent to userspace to start modeset */
schedule_work(&intel_connector->modeset_retry_work);
return;
--
2.23.1
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