Add a connector debugfs entry to force a failure during the following
1-2 link training. The entry will auto-reset after the specified link
training events are complete.
Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx>
---
.../drm/i915/display/intel_display_debugfs.c | 47 +++++++++++++++++++
.../drm/i915/display/intel_display_types.h | 1 +
.../drm/i915/display/intel_dp_link_training.c | 5 +-
3 files changed, 52 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/display/intel_display_debugfs.c b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
index 521721a20358f..098d0f5190723 100644
--- a/drivers/gpu/drm/i915/display/intel_display_debugfs.c
+++ b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
@@ -1525,6 +1525,50 @@ static ssize_t i915_dp_requested_lane_count_write(struct file *file,
}
DEFINE_SHOW_STORE_ATTRIBUTE(i915_dp_requested_lane_count);
+static int i915_dp_force_link_training_failure_show(void *data, u64 *val)
+{
+ struct intel_connector *connector = to_intel_connector(data);
+ struct drm_i915_private *i915 = to_i915(connector->base.dev);
+ struct intel_dp *intel_dp;
+ int err;
+
+ err = drm_modeset_lock_single_interruptible(&i915->drm.mode_config.connection_mutex);
+ if (err)
+ return err;
+
+ intel_dp = intel_connector_to_intel_dp(connector);
+ *val = intel_dp->link_train.force_failure;
+
+ drm_modeset_unlock(&i915->drm.mode_config.connection_mutex);
+
+ return 0;
+}
+
+static int i915_dp_force_link_training_failure_write(void *data, u64 val)
+{
+ struct intel_connector *connector = to_intel_connector(data);
+ struct drm_i915_private *i915 = to_i915(connector->base.dev);
+ struct intel_dp *intel_dp;
+ int err;
+
+ if (val > 2)
+ return -EINVAL;
+
+ err = drm_modeset_lock_single_interruptible(&i915->drm.mode_config.connection_mutex);
+ if (err)
+ return err;
+
+ intel_dp = intel_connector_to_intel_dp(connector);
+ intel_dp->link_train.force_failure = val;
+
+ drm_modeset_unlock(&i915->drm.mode_config.connection_mutex);
+
+ return 0;
+}
+DEFINE_DEBUGFS_ATTRIBUTE(i915_dp_force_link_training_failure_fops,
+ i915_dp_force_link_training_failure_show,
+ i915_dp_force_link_training_failure_write, "%llu\n");
+
static int i915_dsc_output_format_show(struct seq_file *m, void *data)
{
struct intel_connector *connector = m->private;
@@ -1739,6 +1783,9 @@ void intel_connector_debugfs_add(struct intel_connector *connector)
debugfs_create_file("i915_dp_lane_count", 0644, root,
connector, &i915_dp_requested_lane_count_fops);
+
+ debugfs_create_file("i915_dp_force_link_training_failure", 0644, root,
+ connector, &i915_dp_force_link_training_failure_fops);
}
if (DISPLAY_VER(i915) >= 11 &&
diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index 351c445d3cb5b..62acec5236052 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -1768,6 +1768,7 @@ struct intel_dp {
bool retrain_disabled;
/* Sequential failures after a passing LT */
int seq_failures;
+ int force_failure;
} link_train;
bool reset_link_params;
int mso_link_count;
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 352c77f46015e..c260299c53b7c 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_link_training.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.c
@@ -1484,7 +1484,10 @@ void intel_dp_start_link_train(struct intel_dp *intel_dp,
else
passed = intel_dp_link_train_all_phys(intel_dp, crtc_state, lttpr_count);
- if (passed) {
+ if (intel_dp->link_train.force_failure) {
+ intel_dp->link_train.force_failure--;
+ lt_dbg(intel_dp, DP_PHY_DPRX, "Forcing link training failure\n");
+ } else if (passed) {
intel_dp->link_train.seq_failures = 0;
intel_dp_queue_link_check(intel_dp, 2000);
return;
--
2.43.3
