Add a connector debugfs entry to force retrain an active link. This can
be used to test both custom link parameters (previously set via the
target link lane count/rate entries) or link train failure scenarios
(previously forced via the force-failure entry). The entry will
autoreset after the link-retrain is complete.
Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx>
---
.../drm/i915/display/intel_display_debugfs.c | 46 +++++++++++++++++++
.../drm/i915/display/intel_display_types.h | 1 +
drivers/gpu/drm/i915/display/intel_dp.c | 18 ++++++--
3 files changed, 60 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_display_debugfs.c b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
index 098d0f5190723..4f19d30e6972f 100644
--- a/drivers/gpu/drm/i915/display/intel_display_debugfs.c
+++ b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
@@ -1569,6 +1569,49 @@ 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_dp_force_link_retrain_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_retrain;
+
+ drm_modeset_unlock(&i915->drm.mode_config.connection_mutex);
+
+ return 0;
+}
+
+static int i915_dp_force_link_retrain_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;
+
+ 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_retrain = val;
+ intel_hpd_trigger_irq(dp_to_dig_port(intel_dp));
+
+ drm_modeset_unlock(&i915->drm.mode_config.connection_mutex);
+
+ return 0;
+}
+DEFINE_DEBUGFS_ATTRIBUTE(i915_dp_force_link_retrain_fops,
+ i915_dp_force_link_retrain_show,
+ i915_dp_force_link_retrain_write, "%llu\n");
+
static int i915_dsc_output_format_show(struct seq_file *m, void *data)
{
struct intel_connector *connector = m->private;
@@ -1786,6 +1829,9 @@ void intel_connector_debugfs_add(struct intel_connector *connector)
debugfs_create_file("i915_dp_force_link_training_failure", 0644, root,
connector, &i915_dp_force_link_training_failure_fops);
+
+ debugfs_create_file("i915_dp_force_link_retrain", 0644, root,
+ connector, &i915_dp_force_link_retrain_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 62acec5236052..345e2883d9cfc 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -1769,6 +1769,7 @@ struct intel_dp {
/* Sequential failures after a passing LT */
int seq_failures;
int force_failure;
+ bool force_retrain;
} link_train;
bool reset_link_params;
int mso_link_count;
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 367970f956863..28842ae51039a 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -5042,7 +5042,7 @@ intel_dp_check_mst_status(struct intel_dp *intel_dp)
drm_dp_mst_hpd_irq_send_new_request(&intel_dp->mst_mgr);
}
- if (!link_ok)
+ if (!link_ok || intel_dp->link_train.force_retrain)
intel_dp_queue_link_check(intel_dp, 0);
return !reprobe_needed;
@@ -5091,6 +5091,9 @@ intel_dp_needs_link_retrain(struct intel_dp *intel_dp)
if (intel_psr_enabled(intel_dp))
return false;
+ if (intel_dp->link_train.force_retrain)
+ return true;
+
if (drm_dp_dpcd_read_phy_link_status(&intel_dp->aux, DP_PHY_DPRX,
link_status) < 0)
return false;
@@ -5229,8 +5232,9 @@ static int intel_dp_retrain_link(struct intel_encoder *encoder,
if (!intel_dp_needs_link_retrain(intel_dp))
return 0;
- drm_dbg_kms(&dev_priv->drm, "[ENCODER:%d:%s] retraining link\n",
- encoder->base.base.id, encoder->base.name);
+ drm_dbg_kms(&dev_priv->drm, "[ENCODER:%d:%s] retraining link (forced %s)\n",
+ encoder->base.base.id, encoder->base.name,
+ str_yes_no(intel_dp->link_train.force_retrain));
for_each_intel_crtc_in_pipe_mask(&dev_priv->drm, crtc, pipe_mask) {
const struct intel_crtc_state *crtc_state =
@@ -5258,7 +5262,7 @@ static int intel_dp_retrain_link(struct intel_encoder *encoder,
encoder->base.base.id, encoder->base.name,
ERR_PTR(ret));
- return ret;
+ goto out;
}
for_each_intel_crtc_in_pipe_mask(&dev_priv->drm, crtc, pipe_mask) {
@@ -5285,7 +5289,11 @@ static int intel_dp_retrain_link(struct intel_encoder *encoder,
intel_crtc_pch_transcoder(crtc), true);
}
- return 0;
+out:
+ if (ret != -EDEADLK)
+ intel_dp->link_train.force_retrain = false;
+
+ return ret;
}
static void intel_dp_link_check_work_fn(struct work_struct *work)
--
2.43.3
