| Message ID | 20240520185822.3725844-20-imre.deak@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/i915/dp_mst: Enable link training fallback | expand |
On Mon, May 20, 2024 at 09:58:17PM +0300, Imre Deak wrote: > 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) > > Cc: Jani Nikula <jani.nikula@intel.com> > Signed-off-by: Imre Deak <imre.deak@intel.com> > --- > .../drm/i915/display/intel_display_types.h | 1 + > .../drm/i915/display/intel_dp_link_training.c | 52 ++++++++++++++++++- > 2 files changed, 52 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h > index e1c41cece249d..dbe1468fe471d 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 764187bc42ff9..b40148a42f442 100644 > --- a/drivers/gpu/drm/i915/display/intel_dp_link_training.c > +++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.c > @@ -1489,7 +1489,10 @@ 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_ddi_queue_link_check(dig_port, 2000); > return; > @@ -1799,6 +1802,50 @@ 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; > + 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.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; > + int err; > + > + if (val > 2) Why 2 specifically? > + 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.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; > @@ -1818,4 +1865,7 @@ 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
On Thu, May 23, 2024 at 06:29:34PM +0300, Ville Syrjälä wrote: > On Mon, May 20, 2024 at 09:58:17PM +0300, Imre Deak wrote: > > 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) > > > > Cc: Jani Nikula <jani.nikula@intel.com> > > Signed-off-by: Imre Deak <imre.deak@intel.com> > > --- > > .../drm/i915/display/intel_display_types.h | 1 + > > .../drm/i915/display/intel_dp_link_training.c | 52 ++++++++++++++++++- > > 2 files changed, 52 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h > > index e1c41cece249d..dbe1468fe471d 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 764187bc42ff9..b40148a42f442 100644 > > --- a/drivers/gpu/drm/i915/display/intel_dp_link_training.c > > +++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.c > > @@ -1489,7 +1489,10 @@ 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_ddi_queue_link_check(dig_port, 2000); > > return; > > @@ -1799,6 +1802,50 @@ 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; > > + 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.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; > > + int err; > > + > > + if (val > 2) > > Why 2 specifically? There are 2 back-to-back link trainings that can fail after a modeset or later after detecting a bad link state, the initial one and a second with the same LT parameters. That's followed by reducing the LT parameters and probably a modeset changing the mode. > > + 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.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; > > @@ -1818,4 +1865,7 @@ 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 > > -- > Ville Syrjälä > Intel
diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h index e1c41cece249d..dbe1468fe471d 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 764187bc42ff9..b40148a42f442 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_link_training.c +++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.c @@ -1489,7 +1489,10 @@ 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_ddi_queue_link_check(dig_port, 2000); return; @@ -1799,6 +1802,50 @@ 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; + 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.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; + 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.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; @@ -1818,4 +1865,7 @@ 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); }
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) Cc: Jani Nikula <jani.nikula@intel.com> Signed-off-by: Imre Deak <imre.deak@intel.com> --- .../drm/i915/display/intel_display_types.h | 1 + .../drm/i915/display/intel_dp_link_training.c | 52 ++++++++++++++++++- 2 files changed, 52 insertions(+), 1 deletion(-)