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-rw-r--r--drivers/gpu/drm/i915/intel_dp.c25
1 files changed, 18 insertions, 7 deletions
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 8e37fdd1fa2f..7101b8b4f8b4 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1581,7 +1581,7 @@ intel_dp_start_link_train(struct intel_dp *intel_dp)
int i;
uint8_t voltage;
bool clock_recovery = false;
- int tries;
+ int voltage_tries, loop_tries;
u32 reg;
uint32_t DP = intel_dp->DP;
@@ -1608,7 +1608,8 @@ intel_dp_start_link_train(struct intel_dp *intel_dp)
DP &= ~DP_LINK_TRAIN_MASK;
memset(intel_dp->train_set, 0, 4);
voltage = 0xff;
- tries = 0;
+ voltage_tries = 0;
+ loop_tries = 0;
clock_recovery = false;
for (;;) {
/* Use intel_dp->train_set[0] to set the voltage and pre emphasis values */
@@ -1651,16 +1652,26 @@ intel_dp_start_link_train(struct intel_dp *intel_dp)
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)
- break;
+ if (i == intel_dp->lane_count) {
+ ++loop_tries;
+ if (loop_tries == 5) {
+ DRM_DEBUG_KMS("too many full retries, give up\n");
+ break;
+ }
+ memset(intel_dp->train_set, 0, 4);
+ voltage_tries = 0;
+ continue;
+ }
/* Check to see if we've tried the same voltage 5 times */
if ((intel_dp->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK) == voltage) {
- ++tries;
- if (tries == 5)
+ ++voltage_tries;
+ if (voltage_tries == 5) {
+ DRM_DEBUG_KMS("too many voltage retries, give up\n");
break;
+ }
} else
- tries = 0;
+ voltage_tries = 0;
voltage = intel_dp->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK;
/* Compute new intel_dp->train_set as requested by target */