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.
v2: Add the entry from intel_dp_link_training.c (Jani) v3: Lock connection_mutex only for the required intel_dp state. (Ville) Cc: Jani Nikula <[email protected]> Cc: Ville Syrjälä <[email protected]> Signed-off-by: Imre Deak <[email protected]> --- .../drm/i915/display/intel_display_types.h | 1 + .../drm/i915/display/intel_dp_link_training.c | 55 ++++++++++++++++++- 2 files changed, 54 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h index 2ece5f0d86cec..1e234da03c4f2 100644 --- a/drivers/gpu/drm/i915/display/intel_display_types.h +++ b/drivers/gpu/drm/i915/display/intel_display_types.h @@ -1770,6 +1770,7 @@ struct intel_dp { bool retrain_disabled; /* Sequential link training failures after a passing LT */ int seq_train_failures; + int force_train_failure; } link; 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 184206067fa61..a6ea92b54c2f4 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_link_training.c +++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.c @@ -1504,7 +1504,10 @@ void intel_dp_start_link_train(struct intel_atomic_state *state, else passed = intel_dp_link_train_all_phys(intel_dp, crtc_state, lttpr_count); - if (passed) { + if (intel_dp->link.force_train_failure) { + intel_dp->link.force_train_failure--; + lt_dbg(intel_dp, DP_PHY_DPRX, "Forcing link training failure\n"); + } else if (passed) { intel_dp->link.seq_train_failures = 0; intel_encoder_link_check_queue_work(encoder, 2000); return; @@ -1539,7 +1542,10 @@ void intel_dp_start_link_train(struct intel_atomic_state *state, intel_dp->link.retrain_disabled = true; - lt_err(intel_dp, DP_PHY_DPRX, "Can't reduce link training parameters after failure\n"); + if (!passed) + lt_err(intel_dp, DP_PHY_DPRX, "Can't reduce link training parameters after failure\n"); + else + lt_dbg(intel_dp, DP_PHY_DPRX, "Can't reduce link training parameters after forced failure\n"); } void intel_dp_128b132b_sdp_crc16(struct intel_dp *intel_dp, @@ -1808,6 +1814,48 @@ static int i915_dp_max_lane_count_show(void *data, u64 *val) } DEFINE_DEBUGFS_ATTRIBUTE(i915_dp_max_lane_count_fops, i915_dp_max_lane_count_show, NULL, "%llu\n"); +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 = intel_connector_to_intel_dp(connector); + int err; + + err = drm_modeset_lock_single_interruptible(&i915->drm.mode_config.connection_mutex); + if (err) + return err; + + *val = intel_dp->link.force_train_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 = intel_connector_to_intel_dp(connector); + 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->link.force_train_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"); + void intel_dp_link_training_debugfs_add(struct intel_connector *connector) { struct dentry *root = connector->base.debugfs_entry; @@ -1827,4 +1875,7 @@ void intel_dp_link_training_debugfs_add(struct intel_connector *connector) debugfs_create_file("i915_dp_max_lane_count", 0444, root, connector, &i915_dp_max_lane_count_fops); + + debugfs_create_file("i915_dp_force_link_training_failure", 0644, root, + connector, &i915_dp_force_link_training_failure_fops); } -- 2.43.3
