| Message ID | 1477093543-11622-6-git-send-email-manasi.d.navare@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Oct 21, 2016 at 04:45:43PM -0700, Manasi Navare wrote: > If link training at a link rate optimal for a particular > mode fails during modeset's atomic commit phase, then we > let the modeset complete and then retry. We save the link rate > value at which link training failed and use a lower link rate > to prune the modes. It will redo the modeset on the current mode > at lower link rate or if the current mode gets pruned due to lower > link constraints then, it will send a hotplug uevent for userspace > to handle it. > > This is also required to pass DP CTS tests 4.3.1.3, 4.3.1.4, > 4.3.1.6. > > Cc: Jani Nikula <jani.nikula@linux.intel.com> > Cc: Daniel Vetter <daniel.vetter@intel.com> > Cc: Ville Syrjala <ville.syrjala@linux.intel.com> > Signed-off-by: Manasi Navare <manasi.d.navare@intel.com> > --- > drivers/gpu/drm/i915/intel_ddi.c | 15 +++++- > drivers/gpu/drm/i915/intel_dp.c | 69 ++++++++++++++++++++++++++- > drivers/gpu/drm/i915/intel_dp_link_training.c | 12 +++-- > drivers/gpu/drm/i915/intel_drv.h | 6 ++- > 4 files changed, 95 insertions(+), 7 deletions(-) > > diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c > index fb18d69..451433b 100644 > --- a/drivers/gpu/drm/i915/intel_ddi.c > +++ b/drivers/gpu/drm/i915/intel_ddi.c > @@ -1712,6 +1712,8 @@ static void intel_ddi_pre_enable_dp(struct intel_encoder *encoder, > struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base); > struct drm_i915_private *dev_priv = to_i915(encoder->base.dev); > enum port port = intel_ddi_get_encoder_port(encoder); > + struct intel_connector *intel_connector = intel_dp->attached_connector; > + struct drm_connector *connector = &intel_connector->base; > > intel_dp_set_link_params(intel_dp, link_rate, lane_count, > link_mst); > @@ -1722,7 +1724,18 @@ static void intel_ddi_pre_enable_dp(struct intel_encoder *encoder, > intel_prepare_dp_ddi_buffers(encoder); > intel_ddi_init_dp_buf_reg(encoder); > intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON); > - intel_dp_start_link_train(intel_dp); > + if (!intel_dp_start_link_train(intel_dp)) { > + DRM_ERROR("Link Training failed at link rate = %d, lane count = %d\n", > + link_rate, lane_count); I don't think this should be a DRM_ERROR, since it's a part of the normal fallback mechanism. > + intel_dp->link_train_failed = true; > + intel_dp->link_train_failed_link_rate = link_rate; > + intel_dp->link_train_failed_lane_count = lane_count; > + /* Schedule a Hotplug Uevent to userspace to start modeset */ Minor nit, no caps needed for "Hotplug" or "Uevent." Jim > + schedule_work(&connector->i915_modeset_retry_work); > + } else { > + intel_dp->link_train_failed = false; > + } > + > if (port != PORT_A || INTEL_GEN(dev_priv) >= 9) > intel_dp_stop_link_train(intel_dp); > } > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c > index c192e18..5d5f4a7 100644 > --- a/drivers/gpu/drm/i915/intel_dp.c > +++ b/drivers/gpu/drm/i915/intel_dp.c > @@ -313,6 +313,7 @@ static int intel_dp_link_rate_index(struct intel_dp *intel_dp, > int target_clock = mode->clock; > int max_rate, mode_rate, max_lanes, max_link_clock; > int max_dotclk; > + int common_rates[DP_MAX_SUPPORTED_RATES] = {}; > > max_dotclk = intel_dp_downstream_max_dotclock(intel_dp); > > @@ -326,8 +327,27 @@ static int intel_dp_link_rate_index(struct intel_dp *intel_dp, > target_clock = fixed_mode->clock; > } > > - max_link_clock = intel_dp_max_link_rate(intel_dp); > - max_lanes = intel_dp_max_lane_count(intel_dp); > + /* Prune the modes based on the link rate that failed */ > + if (intel_dp->link_train_failed_link_rate) { > + intel_dp->link_rate_index = intel_dp_link_rate_index(intel_dp, > + common_rates, > + intel_dp->link_train_failed_link_rate); > + if (intel_dp->link_rate_index > 0) { > + max_link_clock = common_rates[intel_dp->link_rate_index - 1]; > + max_lanes = intel_dp_max_lane_count(intel_dp); > + } else { > + /* Here we can lower the lane count, but that will be > + * added for DP Spec 1.3 > + */ > + DRM_ERROR("No Valid Mode Supported for this Link\n"); > + intel_dp->link_train_failed_link_rate = 0; > + intel_dp->link_rate_index = -1; > + intel_dp->link_train_failed = false; > + } > + } else { > + max_link_clock = intel_dp_max_link_rate(intel_dp); > + max_lanes = intel_dp_max_lane_count(intel_dp); > + } > > max_rate = intel_dp_max_data_rate(max_link_clock, max_lanes); > mode_rate = intel_dp_link_required(target_clock, 18); > @@ -1619,6 +1639,14 @@ static int intel_dp_compute_bpp(struct intel_dp *intel_dp, > if (adjusted_mode->flags & DRM_MODE_FLAG_DBLCLK) > return false; > > + /* Fall back to lower link rate in case of failure in previous modeset */ > + if (intel_dp->link_train_failed_link_rate) { > + min_lane_count = max_lane_count; > + min_clock = max_clock = intel_dp->link_rate_index - 1; > + intel_dp->link_train_failed_link_rate = 0; > + intel_dp->link_rate_index = -1; > + } > + > DRM_DEBUG_KMS("DP link computation with max lane count %i " > "max bw %d pixel clock %iKHz\n", > max_lane_count, common_rates[max_clock], > @@ -5689,6 +5717,39 @@ static bool intel_edp_init_connector(struct intel_dp *intel_dp, > return false; > } > > +static void intel_dp_modeset_retry_work_fn(struct work_struct *work) > +{ > + struct drm_connector *connector; > + struct intel_dp *intel_dp; > + struct drm_display_mode *mode; > + bool verbose_prune = true; > + bool reprobe = false; > + > + connector = container_of(work, typeof(*connector), > + i915_modeset_retry_work); > + intel_dp = intel_attached_dp(connector); > + > + /* Grab the locks before changing connector property*/ > + mutex_lock(&connector->dev->mode_config.mutex); > + DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id, > + connector->name); > + list_for_each_entry(mode, &connector->modes, head) { > + mode->status = intel_dp_mode_valid(connector, > + mode); > + if (mode->status != MODE_OK) > + reprobe = true; > + } > + drm_mode_prune_invalid(connector->dev, &connector->modes, > + verbose_prune); > + mutex_unlock(&connector->dev->mode_config.mutex); > + if (reprobe) { > + /* Send Hotplug uevent so userspace can reprobe */ > + drm_kms_helper_hotplug_event(connector->dev); > + } > + if (intel_dp->link_train_failed) > + drm_atomic_helper_connector_modeset(connector); > +} > + > bool > intel_dp_init_connector(struct intel_digital_port *intel_dig_port, > struct intel_connector *intel_connector) > @@ -5701,6 +5762,10 @@ static bool intel_edp_init_connector(struct intel_dp *intel_dp, > enum port port = intel_dig_port->port; > int type; > > + /* Initialize the work for modeset in case of link train failure */ > + INIT_WORK(&connector->i915_modeset_retry_work, > + intel_dp_modeset_retry_work_fn); > + > if (WARN(intel_dig_port->max_lanes < 1, > "Not enough lanes (%d) for DP on port %c\n", > intel_dig_port->max_lanes, port_name(port))) > diff --git a/drivers/gpu/drm/i915/intel_dp_link_training.c b/drivers/gpu/drm/i915/intel_dp_link_training.c > index 0048b52..10f81ab 100644 > --- a/drivers/gpu/drm/i915/intel_dp_link_training.c > +++ b/drivers/gpu/drm/i915/intel_dp_link_training.c > @@ -310,9 +310,15 @@ void intel_dp_stop_link_train(struct intel_dp *intel_dp) > DP_TRAINING_PATTERN_DISABLE); > } > > -void > +bool > intel_dp_start_link_train(struct intel_dp *intel_dp) > { > - intel_dp_link_training_clock_recovery(intel_dp); > - intel_dp_link_training_channel_equalization(intel_dp); > + bool ret; > + > + if (intel_dp_link_training_clock_recovery(intel_dp)) { > + ret = intel_dp_link_training_channel_equalization(intel_dp); > + if (ret) > + return true; > + } > + return false; > } > diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h > index 4e90b07..d3fcffc 100644 > --- a/drivers/gpu/drm/i915/intel_drv.h > +++ b/drivers/gpu/drm/i915/intel_drv.h > @@ -890,6 +890,10 @@ struct intel_dp { > uint32_t DP; > int link_rate; > uint8_t lane_count; > + int link_train_failed_link_rate; > + uint8_t link_train_failed_lane_count; > + int link_rate_index; > + bool link_train_failed; > uint8_t sink_count; > bool link_mst; > bool has_audio; > @@ -1394,7 +1398,7 @@ bool intel_dp_init_connector(struct intel_digital_port *intel_dig_port, > void intel_dp_set_link_params(struct intel_dp *intel_dp, > int link_rate, uint8_t lane_count, > bool link_mst); > -void intel_dp_start_link_train(struct intel_dp *intel_dp); > +bool intel_dp_start_link_train(struct intel_dp *intel_dp); > void intel_dp_stop_link_train(struct intel_dp *intel_dp); > void intel_dp_sink_dpms(struct intel_dp *intel_dp, int mode); > void intel_dp_encoder_reset(struct drm_encoder *encoder); > -- > 1.9.1 > > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
On Fri, 2016-10-21 at 16:45 -0700, Manasi Navare wrote: > If link training at a link rate optimal for a particular > mode fails during modeset's atomic commit phase, then we > let the modeset complete and then retry. We save the link rate > value at which link training failed and use a lower link rate > to prune the modes. It will redo the modeset on the current mode > at lower link rate or if the current mode gets pruned due to lower > link constraints then, it will send a hotplug uevent for userspace > to handle it. > > This is also required to pass DP CTS tests 4.3.1.3, 4.3.1.4, > 4.3.1.6. > > Cc: Jani Nikula <jani.nikula@linux.intel.com> > Cc: Daniel Vetter <daniel.vetter@intel.com> > Cc: Ville Syrjala <ville.syrjala@linux.intel.com> > Signed-off-by: Manasi Navare <manasi.d.navare@intel.com> > --- > drivers/gpu/drm/i915/intel_ddi.c | 15 +++++- > drivers/gpu/drm/i915/intel_dp.c | 69 ++++++++++++++++++++++++++- > drivers/gpu/drm/i915/intel_dp_link_training.c | 12 +++-- > drivers/gpu/drm/i915/intel_drv.h | 6 ++- > 4 files changed, 95 insertions(+), 7 deletions(-) > > diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c > index fb18d69..451433b 100644 > --- a/drivers/gpu/drm/i915/intel_ddi.c > +++ b/drivers/gpu/drm/i915/intel_ddi.c > @@ -1712,6 +1712,8 @@ static void intel_ddi_pre_enable_dp(struct intel_encoder *encoder, > struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base); > struct drm_i915_private *dev_priv = to_i915(encoder->base.dev); > enum port port = intel_ddi_get_encoder_port(encoder); > + struct intel_connector *intel_connector = intel_dp->attached_connector; > + struct drm_connector *connector = &intel_connector->base; > > intel_dp_set_link_params(intel_dp, link_rate, lane_count, > link_mst); > @@ -1722,7 +1724,18 @@ static void intel_ddi_pre_enable_dp(struct intel_encoder *encoder, > intel_prepare_dp_ddi_buffers(encoder); > intel_ddi_init_dp_buf_reg(encoder); > intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON); > - intel_dp_start_link_train(intel_dp); > + if (!intel_dp_start_link_train(intel_dp)) { > + DRM_ERROR("Link Training failed at link rate = %d, lane count = %d\n", > + link_rate, lane_count); > + intel_dp->link_train_failed = true; > + intel_dp->link_train_failed_link_rate = link_rate; > + intel_dp->link_train_failed_lane_count = lane_count; > + /* Schedule a Hotplug Uevent to userspace to start modeset */ > + schedule_work(&connector->i915_modeset_retry_work); > + } else { > + intel_dp->link_train_failed = false; > + } > + > if (port != PORT_A || INTEL_GEN(dev_priv) >= 9) > intel_dp_stop_link_train(intel_dp); > } > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c > index c192e18..5d5f4a7 100644 > --- a/drivers/gpu/drm/i915/intel_dp.c > +++ b/drivers/gpu/drm/i915/intel_dp.c > @@ -313,6 +313,7 @@ static int intel_dp_link_rate_index(struct intel_dp *intel_dp, > int target_clock = mode->clock; > int max_rate, mode_rate, max_lanes, max_link_clock; > int max_dotclk; > + int common_rates[DP_MAX_SUPPORTED_RATES] = {}; > > max_dotclk = intel_dp_downstream_max_dotclock(intel_dp); > > @@ -326,8 +327,27 @@ static int intel_dp_link_rate_index(struct intel_dp *intel_dp, > target_clock = fixed_mode->clock; > } > > - max_link_clock = intel_dp_max_link_rate(intel_dp); > - max_lanes = intel_dp_max_lane_count(intel_dp); > + /* Prune the modes based on the link rate that failed */ > + if (intel_dp->link_train_failed_link_rate) { Shouldn't the bool link_train_failed that you are adding be used here? The naming indicates a check like this should use that. > + intel_dp->link_rate_index = intel_dp_link_rate_index(intel_dp, > + common_rates, > + intel_dp->link_train_failed_link_rate); > + if (intel_dp->link_rate_index > 0) { > + max_link_clock = common_rates[intel_dp->link_rate_index - 1]; > + max_lanes = intel_dp_max_lane_count(intel_dp); > + } else { > + /* Here we can lower the lane count, but that will be > + * added for DP Spec 1.3 > + */ > + DRM_ERROR("No Valid Mode Supported for this Link\n"); > + intel_dp->link_train_failed_link_rate = 0; > + intel_dp->link_rate_index = -1; > + intel_dp->link_train_failed = false; 1. You are not setting max_link_clock and max_lanes here. Won't this end up computing the max_rate based on uninitialized locals? 2. Also, what is the correct return value in this case? 3. You are resetting all values when a link rate cannot be found, what link rate is the subsequent modeset expected to start from? -DK > + } > + } else { > + max_link_clock = intel_dp_max_link_rate(intel_dp); > + max_lanes = intel_dp_max_lane_count(intel_dp); > + } > > max_rate = intel_dp_max_data_rate(max_link_clock, max_lanes); > mode_rate = intel_dp_link_required(target_clock, 18); > @@ -1619,6 +1639,14 @@ static int intel_dp_compute_bpp(struct intel_dp *intel_dp, > if (adjusted_mode->flags & DRM_MODE_FLAG_DBLCLK) > return false; > > + /* Fall back to lower link rate in case of failure in previous modeset */ > + if (intel_dp->link_train_failed_link_rate) { > + min_lane_count = max_lane_count; > + min_clock = max_clock = intel_dp->link_rate_index - 1; 1. Why is min_clock same as max_clock? This forces the clock to a value instead of iterating it based on the mode rate. 2. Why is min_lane_count set to max_lane_count? Is this done to be Spec compliant? 3. What about bpp? Looks like the we will still be iterating over bpp to find the link rate. -DK > + intel_dp->link_train_failed_link_rate = 0; > + intel_dp->link_rate_index = -1; > + } > + > DRM_DEBUG_KMS("DP link computation with max lane count %i " > "max bw %d pixel clock %iKHz\n", > max_lane_count, common_rates[max_clock], > @@ -5689,6 +5717,39 @@ static bool intel_edp_init_connector(struct intel_dp *intel_dp, > return false; > } > > +static void intel_dp_modeset_retry_work_fn(struct work_struct *work) > +{ > + struct drm_connector *connector; > + struct intel_dp *intel_dp; > + struct drm_display_mode *mode; > + bool verbose_prune = true; > + bool reprobe = false; > + > + connector = container_of(work, typeof(*connector), > + i915_modeset_retry_work); > + intel_dp = intel_attached_dp(connector); > + > + /* Grab the locks before changing connector property*/ > + mutex_lock(&connector->dev->mode_config.mutex); > + DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id, > + connector->name); > + list_for_each_entry(mode, &connector->modes, head) { > + mode->status = intel_dp_mode_valid(connector, > + mode); > + if (mode->status != MODE_OK) > + reprobe = true; > + } > + drm_mode_prune_invalid(connector->dev, &connector->modes, > + verbose_prune); > + mutex_unlock(&connector->dev->mode_config.mutex); > + if (reprobe) { > + /* Send Hotplug uevent so userspace can reprobe */ > + drm_kms_helper_hotplug_event(connector->dev); > + } > + if (intel_dp->link_train_failed) > + drm_atomic_helper_connector_modeset(connector); > +} > + > bool > intel_dp_init_connector(struct intel_digital_port *intel_dig_port, > struct intel_connector *intel_connector) > @@ -5701,6 +5762,10 @@ static bool intel_edp_init_connector(struct intel_dp *intel_dp, > enum port port = intel_dig_port->port; > int type; > > + /* Initialize the work for modeset in case of link train failure */ > + INIT_WORK(&connector->i915_modeset_retry_work, > + intel_dp_modeset_retry_work_fn); > + > if (WARN(intel_dig_port->max_lanes < 1, > "Not enough lanes (%d) for DP on port %c\n", > intel_dig_port->max_lanes, port_name(port))) > diff --git a/drivers/gpu/drm/i915/intel_dp_link_training.c b/drivers/gpu/drm/i915/intel_dp_link_training.c > index 0048b52..10f81ab 100644 > --- a/drivers/gpu/drm/i915/intel_dp_link_training.c > +++ b/drivers/gpu/drm/i915/intel_dp_link_training.c > @@ -310,9 +310,15 @@ void intel_dp_stop_link_train(struct intel_dp *intel_dp) > DP_TRAINING_PATTERN_DISABLE); > } > > -void > +bool > intel_dp_start_link_train(struct intel_dp *intel_dp) > { > - intel_dp_link_training_clock_recovery(intel_dp); > - intel_dp_link_training_channel_equalization(intel_dp); > + bool ret; > + > + if (intel_dp_link_training_clock_recovery(intel_dp)) { > + ret = intel_dp_link_training_channel_equalization(intel_dp); > + if (ret) > + return true; > + } > + return false; > } > diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h > index 4e90b07..d3fcffc 100644 > --- a/drivers/gpu/drm/i915/intel_drv.h > +++ b/drivers/gpu/drm/i915/intel_drv.h > @@ -890,6 +890,10 @@ struct intel_dp { > uint32_t DP; > int link_rate; > uint8_t lane_count; > + int link_train_failed_link_rate; > + uint8_t link_train_failed_lane_count; > + int link_rate_index; > + bool link_train_failed; > uint8_t sink_count; > bool link_mst; > bool has_audio; > @@ -1394,7 +1398,7 @@ bool intel_dp_init_connector(struct intel_digital_port *intel_dig_port, > void intel_dp_set_link_params(struct intel_dp *intel_dp, > int link_rate, uint8_t lane_count, > bool link_mst); > -void intel_dp_start_link_train(struct intel_dp *intel_dp); > +bool intel_dp_start_link_train(struct intel_dp *intel_dp); > void intel_dp_stop_link_train(struct intel_dp *intel_dp); > void intel_dp_sink_dpms(struct intel_dp *intel_dp, int mode); > void intel_dp_encoder_reset(struct drm_encoder *encoder);
On Sat, 22 Oct 2016, Manasi Navare <manasi.d.navare@intel.com> wrote: > If link training at a link rate optimal for a particular > mode fails during modeset's atomic commit phase, then we > let the modeset complete and then retry. We save the link rate > value at which link training failed and use a lower link rate > to prune the modes. It will redo the modeset on the current mode > at lower link rate or if the current mode gets pruned due to lower > link constraints then, it will send a hotplug uevent for userspace > to handle it. > > This is also required to pass DP CTS tests 4.3.1.3, 4.3.1.4, > 4.3.1.6. > > Cc: Jani Nikula <jani.nikula@linux.intel.com> > Cc: Daniel Vetter <daniel.vetter@intel.com> > Cc: Ville Syrjala <ville.syrjala@linux.intel.com> > Signed-off-by: Manasi Navare <manasi.d.navare@intel.com> > --- > drivers/gpu/drm/i915/intel_ddi.c | 15 +++++- > drivers/gpu/drm/i915/intel_dp.c | 69 ++++++++++++++++++++++++++- > drivers/gpu/drm/i915/intel_dp_link_training.c | 12 +++-- > drivers/gpu/drm/i915/intel_drv.h | 6 ++- > 4 files changed, 95 insertions(+), 7 deletions(-) > > diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c > index fb18d69..451433b 100644 > --- a/drivers/gpu/drm/i915/intel_ddi.c > +++ b/drivers/gpu/drm/i915/intel_ddi.c > @@ -1712,6 +1712,8 @@ static void intel_ddi_pre_enable_dp(struct intel_encoder *encoder, > struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base); > struct drm_i915_private *dev_priv = to_i915(encoder->base.dev); > enum port port = intel_ddi_get_encoder_port(encoder); > + struct intel_connector *intel_connector = intel_dp->attached_connector; > + struct drm_connector *connector = &intel_connector->base; > > intel_dp_set_link_params(intel_dp, link_rate, lane_count, > link_mst); > @@ -1722,7 +1724,18 @@ static void intel_ddi_pre_enable_dp(struct intel_encoder *encoder, > intel_prepare_dp_ddi_buffers(encoder); > intel_ddi_init_dp_buf_reg(encoder); > intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON); > - intel_dp_start_link_train(intel_dp); > + if (!intel_dp_start_link_train(intel_dp)) { > + DRM_ERROR("Link Training failed at link rate = %d, lane count = %d\n", > + link_rate, lane_count); > + intel_dp->link_train_failed = true; > + intel_dp->link_train_failed_link_rate = link_rate; > + intel_dp->link_train_failed_lane_count = lane_count; I think eventually you'll need to store a list (array) of failing link rate, lane count pairs, not just the last that failed. Now you restrict the link config computation to only reducing the link rate. But currently (for whatever reason, it's flip-flopped too many times) we start with wide & slow, meaning that in many cases we've already exhausted the option to go slower. If optimal fails, maybe we need to try narrow & fast instead. BR, Jani. > + /* Schedule a Hotplug Uevent to userspace to start modeset */ > + schedule_work(&connector->i915_modeset_retry_work); > + } else { > + intel_dp->link_train_failed = false; > + } > + > if (port != PORT_A || INTEL_GEN(dev_priv) >= 9) > intel_dp_stop_link_train(intel_dp); > } > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c > index c192e18..5d5f4a7 100644 > --- a/drivers/gpu/drm/i915/intel_dp.c > +++ b/drivers/gpu/drm/i915/intel_dp.c > @@ -313,6 +313,7 @@ static int intel_dp_link_rate_index(struct intel_dp *intel_dp, > int target_clock = mode->clock; > int max_rate, mode_rate, max_lanes, max_link_clock; > int max_dotclk; > + int common_rates[DP_MAX_SUPPORTED_RATES] = {}; > > max_dotclk = intel_dp_downstream_max_dotclock(intel_dp); > > @@ -326,8 +327,27 @@ static int intel_dp_link_rate_index(struct intel_dp *intel_dp, > target_clock = fixed_mode->clock; > } > > - max_link_clock = intel_dp_max_link_rate(intel_dp); > - max_lanes = intel_dp_max_lane_count(intel_dp); > + /* Prune the modes based on the link rate that failed */ > + if (intel_dp->link_train_failed_link_rate) { > + intel_dp->link_rate_index = intel_dp_link_rate_index(intel_dp, > + common_rates, > + intel_dp->link_train_failed_link_rate); > + if (intel_dp->link_rate_index > 0) { > + max_link_clock = common_rates[intel_dp->link_rate_index - 1]; > + max_lanes = intel_dp_max_lane_count(intel_dp); > + } else { > + /* Here we can lower the lane count, but that will be > + * added for DP Spec 1.3 > + */ > + DRM_ERROR("No Valid Mode Supported for this Link\n"); > + intel_dp->link_train_failed_link_rate = 0; > + intel_dp->link_rate_index = -1; > + intel_dp->link_train_failed = false; > + } > + } else { > + max_link_clock = intel_dp_max_link_rate(intel_dp); > + max_lanes = intel_dp_max_lane_count(intel_dp); > + } > > max_rate = intel_dp_max_data_rate(max_link_clock, max_lanes); > mode_rate = intel_dp_link_required(target_clock, 18); > @@ -1619,6 +1639,14 @@ static int intel_dp_compute_bpp(struct intel_dp *intel_dp, > if (adjusted_mode->flags & DRM_MODE_FLAG_DBLCLK) > return false; > > + /* Fall back to lower link rate in case of failure in previous modeset */ > + if (intel_dp->link_train_failed_link_rate) { > + min_lane_count = max_lane_count; > + min_clock = max_clock = intel_dp->link_rate_index - 1; > + intel_dp->link_train_failed_link_rate = 0; > + intel_dp->link_rate_index = -1; > + } > + > DRM_DEBUG_KMS("DP link computation with max lane count %i " > "max bw %d pixel clock %iKHz\n", > max_lane_count, common_rates[max_clock], > @@ -5689,6 +5717,39 @@ static bool intel_edp_init_connector(struct intel_dp *intel_dp, > return false; > } > > +static void intel_dp_modeset_retry_work_fn(struct work_struct *work) > +{ > + struct drm_connector *connector; > + struct intel_dp *intel_dp; > + struct drm_display_mode *mode; > + bool verbose_prune = true; > + bool reprobe = false; > + > + connector = container_of(work, typeof(*connector), > + i915_modeset_retry_work); > + intel_dp = intel_attached_dp(connector); > + > + /* Grab the locks before changing connector property*/ > + mutex_lock(&connector->dev->mode_config.mutex); > + DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id, > + connector->name); > + list_for_each_entry(mode, &connector->modes, head) { > + mode->status = intel_dp_mode_valid(connector, > + mode); > + if (mode->status != MODE_OK) > + reprobe = true; > + } > + drm_mode_prune_invalid(connector->dev, &connector->modes, > + verbose_prune); > + mutex_unlock(&connector->dev->mode_config.mutex); > + if (reprobe) { > + /* Send Hotplug uevent so userspace can reprobe */ > + drm_kms_helper_hotplug_event(connector->dev); > + } > + if (intel_dp->link_train_failed) > + drm_atomic_helper_connector_modeset(connector); > +} > + > bool > intel_dp_init_connector(struct intel_digital_port *intel_dig_port, > struct intel_connector *intel_connector) > @@ -5701,6 +5762,10 @@ static bool intel_edp_init_connector(struct intel_dp *intel_dp, > enum port port = intel_dig_port->port; > int type; > > + /* Initialize the work for modeset in case of link train failure */ > + INIT_WORK(&connector->i915_modeset_retry_work, > + intel_dp_modeset_retry_work_fn); > + > if (WARN(intel_dig_port->max_lanes < 1, > "Not enough lanes (%d) for DP on port %c\n", > intel_dig_port->max_lanes, port_name(port))) > diff --git a/drivers/gpu/drm/i915/intel_dp_link_training.c b/drivers/gpu/drm/i915/intel_dp_link_training.c > index 0048b52..10f81ab 100644 > --- a/drivers/gpu/drm/i915/intel_dp_link_training.c > +++ b/drivers/gpu/drm/i915/intel_dp_link_training.c > @@ -310,9 +310,15 @@ void intel_dp_stop_link_train(struct intel_dp *intel_dp) > DP_TRAINING_PATTERN_DISABLE); > } > > -void > +bool > intel_dp_start_link_train(struct intel_dp *intel_dp) > { > - intel_dp_link_training_clock_recovery(intel_dp); > - intel_dp_link_training_channel_equalization(intel_dp); > + bool ret; > + > + if (intel_dp_link_training_clock_recovery(intel_dp)) { > + ret = intel_dp_link_training_channel_equalization(intel_dp); > + if (ret) > + return true; > + } > + return false; > } > diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h > index 4e90b07..d3fcffc 100644 > --- a/drivers/gpu/drm/i915/intel_drv.h > +++ b/drivers/gpu/drm/i915/intel_drv.h > @@ -890,6 +890,10 @@ struct intel_dp { > uint32_t DP; > int link_rate; > uint8_t lane_count; > + int link_train_failed_link_rate; > + uint8_t link_train_failed_lane_count; > + int link_rate_index; > + bool link_train_failed; > uint8_t sink_count; > bool link_mst; > bool has_audio; > @@ -1394,7 +1398,7 @@ bool intel_dp_init_connector(struct intel_digital_port *intel_dig_port, > void intel_dp_set_link_params(struct intel_dp *intel_dp, > int link_rate, uint8_t lane_count, > bool link_mst); > -void intel_dp_start_link_train(struct intel_dp *intel_dp); > +bool intel_dp_start_link_train(struct intel_dp *intel_dp); > void intel_dp_stop_link_train(struct intel_dp *intel_dp); > void intel_dp_sink_dpms(struct intel_dp *intel_dp, int mode); > void intel_dp_encoder_reset(struct drm_encoder *encoder);
On Tue, Oct 25, 2016 at 03:17:47PM +0300, Jani Nikula wrote: > On Sat, 22 Oct 2016, Manasi Navare <manasi.d.navare@intel.com> wrote: > > If link training at a link rate optimal for a particular > > mode fails during modeset's atomic commit phase, then we > > let the modeset complete and then retry. We save the link rate > > value at which link training failed and use a lower link rate > > to prune the modes. It will redo the modeset on the current mode > > at lower link rate or if the current mode gets pruned due to lower > > link constraints then, it will send a hotplug uevent for userspace > > to handle it. > > > > This is also required to pass DP CTS tests 4.3.1.3, 4.3.1.4, > > 4.3.1.6. > > > > Cc: Jani Nikula <jani.nikula@linux.intel.com> > > Cc: Daniel Vetter <daniel.vetter@intel.com> > > Cc: Ville Syrjala <ville.syrjala@linux.intel.com> > > Signed-off-by: Manasi Navare <manasi.d.navare@intel.com> > > --- > > drivers/gpu/drm/i915/intel_ddi.c | 15 +++++- > > drivers/gpu/drm/i915/intel_dp.c | 69 ++++++++++++++++++++++++++- > > drivers/gpu/drm/i915/intel_dp_link_training.c | 12 +++-- > > drivers/gpu/drm/i915/intel_drv.h | 6 ++- > > 4 files changed, 95 insertions(+), 7 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c > > index fb18d69..451433b 100644 > > --- a/drivers/gpu/drm/i915/intel_ddi.c > > +++ b/drivers/gpu/drm/i915/intel_ddi.c > > @@ -1712,6 +1712,8 @@ static void intel_ddi_pre_enable_dp(struct intel_encoder *encoder, > > struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base); > > struct drm_i915_private *dev_priv = to_i915(encoder->base.dev); > > enum port port = intel_ddi_get_encoder_port(encoder); > > + struct intel_connector *intel_connector = intel_dp->attached_connector; > > + struct drm_connector *connector = &intel_connector->base; > > > > intel_dp_set_link_params(intel_dp, link_rate, lane_count, > > link_mst); > > @@ -1722,7 +1724,18 @@ static void intel_ddi_pre_enable_dp(struct intel_encoder *encoder, > > intel_prepare_dp_ddi_buffers(encoder); > > intel_ddi_init_dp_buf_reg(encoder); > > intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON); > > - intel_dp_start_link_train(intel_dp); > > + if (!intel_dp_start_link_train(intel_dp)) { > > + DRM_ERROR("Link Training failed at link rate = %d, lane count = %d\n", > > + link_rate, lane_count); > > + intel_dp->link_train_failed = true; > > + intel_dp->link_train_failed_link_rate = link_rate; > > + intel_dp->link_train_failed_lane_count = lane_count; > > I think eventually you'll need to store a list (array) of failing link > rate, lane count pairs, not just the last that failed. Now you restrict > the link config computation to only reducing the link rate. But > currently (for whatever reason, it's flip-flopped too many times) we > start with wide & slow, meaning that in many cases we've already > exhausted the option to go slower. If optimal fails, maybe we need to > try narrow & fast instead. The DP spec specifically calls out that lane count shouldn't be reduced until all speeds with the current lane configuration fail. Even if we start at an "optimal" configuration I believe we still need to follow the reduction pattern that the spec calls out. Jim > > BR, > Jani. > > > > + /* Schedule a Hotplug Uevent to userspace to start modeset */ > > + schedule_work(&connector->i915_modeset_retry_work); > > + } else { > > + intel_dp->link_train_failed = false; > > + } > > + > > if (port != PORT_A || INTEL_GEN(dev_priv) >= 9) > > intel_dp_stop_link_train(intel_dp); > > } > > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c > > index c192e18..5d5f4a7 100644 > > --- a/drivers/gpu/drm/i915/intel_dp.c > > +++ b/drivers/gpu/drm/i915/intel_dp.c > > @@ -313,6 +313,7 @@ static int intel_dp_link_rate_index(struct intel_dp *intel_dp, > > int target_clock = mode->clock; > > int max_rate, mode_rate, max_lanes, max_link_clock; > > int max_dotclk; > > + int common_rates[DP_MAX_SUPPORTED_RATES] = {}; > > > > max_dotclk = intel_dp_downstream_max_dotclock(intel_dp); > > > > @@ -326,8 +327,27 @@ static int intel_dp_link_rate_index(struct intel_dp *intel_dp, > > target_clock = fixed_mode->clock; > > } > > > > - max_link_clock = intel_dp_max_link_rate(intel_dp); > > - max_lanes = intel_dp_max_lane_count(intel_dp); > > + /* Prune the modes based on the link rate that failed */ > > + if (intel_dp->link_train_failed_link_rate) { > > + intel_dp->link_rate_index = intel_dp_link_rate_index(intel_dp, > > + common_rates, > > + intel_dp->link_train_failed_link_rate); > > + if (intel_dp->link_rate_index > 0) { > > + max_link_clock = common_rates[intel_dp->link_rate_index - 1]; > > + max_lanes = intel_dp_max_lane_count(intel_dp); > > + } else { > > + /* Here we can lower the lane count, but that will be > > + * added for DP Spec 1.3 > > + */ > > + DRM_ERROR("No Valid Mode Supported for this Link\n"); > > + intel_dp->link_train_failed_link_rate = 0; > > + intel_dp->link_rate_index = -1; > > + intel_dp->link_train_failed = false; > > + } > > + } else { > > + max_link_clock = intel_dp_max_link_rate(intel_dp); > > + max_lanes = intel_dp_max_lane_count(intel_dp); > > + } > > > > max_rate = intel_dp_max_data_rate(max_link_clock, max_lanes); > > mode_rate = intel_dp_link_required(target_clock, 18); > > @@ -1619,6 +1639,14 @@ static int intel_dp_compute_bpp(struct intel_dp *intel_dp, > > if (adjusted_mode->flags & DRM_MODE_FLAG_DBLCLK) > > return false; > > > > + /* Fall back to lower link rate in case of failure in previous modeset */ > > + if (intel_dp->link_train_failed_link_rate) { > > + min_lane_count = max_lane_count; > > + min_clock = max_clock = intel_dp->link_rate_index - 1; > > + intel_dp->link_train_failed_link_rate = 0; > > + intel_dp->link_rate_index = -1; > > + } > > + > > DRM_DEBUG_KMS("DP link computation with max lane count %i " > > "max bw %d pixel clock %iKHz\n", > > max_lane_count, common_rates[max_clock], > > @@ -5689,6 +5717,39 @@ static bool intel_edp_init_connector(struct intel_dp *intel_dp, > > return false; > > } > > > > +static void intel_dp_modeset_retry_work_fn(struct work_struct *work) > > +{ > > + struct drm_connector *connector; > > + struct intel_dp *intel_dp; > > + struct drm_display_mode *mode; > > + bool verbose_prune = true; > > + bool reprobe = false; > > + > > + connector = container_of(work, typeof(*connector), > > + i915_modeset_retry_work); > > + intel_dp = intel_attached_dp(connector); > > + > > + /* Grab the locks before changing connector property*/ > > + mutex_lock(&connector->dev->mode_config.mutex); > > + DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id, > > + connector->name); > > + list_for_each_entry(mode, &connector->modes, head) { > > + mode->status = intel_dp_mode_valid(connector, > > + mode); > > + if (mode->status != MODE_OK) > > + reprobe = true; > > + } > > + drm_mode_prune_invalid(connector->dev, &connector->modes, > > + verbose_prune); > > + mutex_unlock(&connector->dev->mode_config.mutex); > > + if (reprobe) { > > + /* Send Hotplug uevent so userspace can reprobe */ > > + drm_kms_helper_hotplug_event(connector->dev); > > + } > > + if (intel_dp->link_train_failed) > > + drm_atomic_helper_connector_modeset(connector); > > +} > > + > > bool > > intel_dp_init_connector(struct intel_digital_port *intel_dig_port, > > struct intel_connector *intel_connector) > > @@ -5701,6 +5762,10 @@ static bool intel_edp_init_connector(struct intel_dp *intel_dp, > > enum port port = intel_dig_port->port; > > int type; > > > > + /* Initialize the work for modeset in case of link train failure */ > > + INIT_WORK(&connector->i915_modeset_retry_work, > > + intel_dp_modeset_retry_work_fn); > > + > > if (WARN(intel_dig_port->max_lanes < 1, > > "Not enough lanes (%d) for DP on port %c\n", > > intel_dig_port->max_lanes, port_name(port))) > > diff --git a/drivers/gpu/drm/i915/intel_dp_link_training.c b/drivers/gpu/drm/i915/intel_dp_link_training.c > > index 0048b52..10f81ab 100644 > > --- a/drivers/gpu/drm/i915/intel_dp_link_training.c > > +++ b/drivers/gpu/drm/i915/intel_dp_link_training.c > > @@ -310,9 +310,15 @@ void intel_dp_stop_link_train(struct intel_dp *intel_dp) > > DP_TRAINING_PATTERN_DISABLE); > > } > > > > -void > > +bool > > intel_dp_start_link_train(struct intel_dp *intel_dp) > > { > > - intel_dp_link_training_clock_recovery(intel_dp); > > - intel_dp_link_training_channel_equalization(intel_dp); > > + bool ret; > > + > > + if (intel_dp_link_training_clock_recovery(intel_dp)) { > > + ret = intel_dp_link_training_channel_equalization(intel_dp); > > + if (ret) > > + return true; > > + } > > + return false; > > } > > diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h > > index 4e90b07..d3fcffc 100644 > > --- a/drivers/gpu/drm/i915/intel_drv.h > > +++ b/drivers/gpu/drm/i915/intel_drv.h > > @@ -890,6 +890,10 @@ struct intel_dp { > > uint32_t DP; > > int link_rate; > > uint8_t lane_count; > > + int link_train_failed_link_rate; > > + uint8_t link_train_failed_lane_count; > > + int link_rate_index; > > + bool link_train_failed; > > uint8_t sink_count; > > bool link_mst; > > bool has_audio; > > @@ -1394,7 +1398,7 @@ bool intel_dp_init_connector(struct intel_digital_port *intel_dig_port, > > void intel_dp_set_link_params(struct intel_dp *intel_dp, > > int link_rate, uint8_t lane_count, > > bool link_mst); > > -void intel_dp_start_link_train(struct intel_dp *intel_dp); > > +bool intel_dp_start_link_train(struct intel_dp *intel_dp); > > void intel_dp_stop_link_train(struct intel_dp *intel_dp); > > void intel_dp_sink_dpms(struct intel_dp *intel_dp, int mode); > > void intel_dp_encoder_reset(struct drm_encoder *encoder); > > -- > Jani Nikula, Intel Open Source Technology Center > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
On Mon, Oct 24, 2016 at 11:23:39PM -0700, Pandiyan, Dhinakaran wrote: > On Fri, 2016-10-21 at 16:45 -0700, Manasi Navare wrote: > > If link training at a link rate optimal for a particular > > mode fails during modeset's atomic commit phase, then we > > let the modeset complete and then retry. We save the link rate > > value at which link training failed and use a lower link rate > > to prune the modes. It will redo the modeset on the current mode > > at lower link rate or if the current mode gets pruned due to lower > > link constraints then, it will send a hotplug uevent for userspace > > to handle it. > > > > This is also required to pass DP CTS tests 4.3.1.3, 4.3.1.4, > > 4.3.1.6. > > > > Cc: Jani Nikula <jani.nikula@linux.intel.com> > > Cc: Daniel Vetter <daniel.vetter@intel.com> > > Cc: Ville Syrjala <ville.syrjala@linux.intel.com> > > Signed-off-by: Manasi Navare <manasi.d.navare@intel.com> > > --- > > drivers/gpu/drm/i915/intel_ddi.c | 15 +++++- > > drivers/gpu/drm/i915/intel_dp.c | 69 ++++++++++++++++++++++++++- > > drivers/gpu/drm/i915/intel_dp_link_training.c | 12 +++-- > > drivers/gpu/drm/i915/intel_drv.h | 6 ++- > > 4 files changed, 95 insertions(+), 7 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c > > index fb18d69..451433b 100644 > > --- a/drivers/gpu/drm/i915/intel_ddi.c > > +++ b/drivers/gpu/drm/i915/intel_ddi.c > > @@ -1712,6 +1712,8 @@ static void intel_ddi_pre_enable_dp(struct intel_encoder *encoder, > > struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base); > > struct drm_i915_private *dev_priv = to_i915(encoder->base.dev); > > enum port port = intel_ddi_get_encoder_port(encoder); > > + struct intel_connector *intel_connector = intel_dp->attached_connector; > > + struct drm_connector *connector = &intel_connector->base; > > > > intel_dp_set_link_params(intel_dp, link_rate, lane_count, > > link_mst); > > @@ -1722,7 +1724,18 @@ static void intel_ddi_pre_enable_dp(struct intel_encoder *encoder, > > intel_prepare_dp_ddi_buffers(encoder); > > intel_ddi_init_dp_buf_reg(encoder); > > intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON); > > - intel_dp_start_link_train(intel_dp); > > + if (!intel_dp_start_link_train(intel_dp)) { > > + DRM_ERROR("Link Training failed at link rate = %d, lane count = %d\n", > > + link_rate, lane_count); > > + intel_dp->link_train_failed = true; > > + intel_dp->link_train_failed_link_rate = link_rate; > > + intel_dp->link_train_failed_lane_count = lane_count; > > + /* Schedule a Hotplug Uevent to userspace to start modeset */ > > + schedule_work(&connector->i915_modeset_retry_work); > > + } else { > > + intel_dp->link_train_failed = false; > > + } > > + > > if (port != PORT_A || INTEL_GEN(dev_priv) >= 9) > > intel_dp_stop_link_train(intel_dp); > > } > > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c > > index c192e18..5d5f4a7 100644 > > --- a/drivers/gpu/drm/i915/intel_dp.c > > +++ b/drivers/gpu/drm/i915/intel_dp.c > > @@ -313,6 +313,7 @@ static int intel_dp_link_rate_index(struct intel_dp *intel_dp, > > int target_clock = mode->clock; > > int max_rate, mode_rate, max_lanes, max_link_clock; > > int max_dotclk; > > + int common_rates[DP_MAX_SUPPORTED_RATES] = {}; > > > > max_dotclk = intel_dp_downstream_max_dotclock(intel_dp); > > > > @@ -326,8 +327,27 @@ static int intel_dp_link_rate_index(struct intel_dp *intel_dp, > > target_clock = fixed_mode->clock; > > } > > > > - max_link_clock = intel_dp_max_link_rate(intel_dp); > > - max_lanes = intel_dp_max_lane_count(intel_dp); > > + /* Prune the modes based on the link rate that failed */ > > + if (intel_dp->link_train_failed_link_rate) { > > Shouldn't the bool link_train_failed that you are adding be used here? > The naming indicates a check like this should use that. Either that or the link_train_failed_link_rate can be used, both get initialized and reset the same time. But using link_train_failed would be more appropriate I guess, I will look at changing that. Manasi > > > > + intel_dp->link_rate_index = intel_dp_link_rate_index(intel_dp, > > + common_rates, > > + intel_dp->link_train_failed_link_rate); > > + if (intel_dp->link_rate_index > 0) { > > + max_link_clock = common_rates[intel_dp->link_rate_index - 1]; > > + max_lanes = intel_dp_max_lane_count(intel_dp); > > + } else { > > + /* Here we can lower the lane count, but that will be > > + * added for DP Spec 1.3 > > + */ > > + DRM_ERROR("No Valid Mode Supported for this Link\n"); > > + intel_dp->link_train_failed_link_rate = 0; > > + intel_dp->link_rate_index = -1; > > + intel_dp->link_train_failed = false; > > 1. You are not setting max_link_clock and max_lanes here. Won't this end > up computing the max_rate based on uninitialized locals? > > 2. Also, what is the correct return value in this case? > > 3. You are resetting all values when a link rate cannot be found, what > link rate is the subsequent modeset expected to start from? > > > -DK The idea is to just fail the link training in this case since we cannot further reduce the link rate/lane count so it shoudl just fail the modeset and send a uevent to userspace. I think this logic will need further tuning. > > + } > > + } else { > > + max_link_clock = intel_dp_max_link_rate(intel_dp); > > + max_lanes = intel_dp_max_lane_count(intel_dp); > > + } > > > > max_rate = intel_dp_max_data_rate(max_link_clock, max_lanes); > > mode_rate = intel_dp_link_required(target_clock, 18); > > @@ -1619,6 +1639,14 @@ static int intel_dp_compute_bpp(struct intel_dp *intel_dp, > > if (adjusted_mode->flags & DRM_MODE_FLAG_DBLCLK) > > return false; > > > > + /* Fall back to lower link rate in case of failure in previous modeset */ > > + if (intel_dp->link_train_failed_link_rate) { > > + min_lane_count = max_lane_count; > > + min_clock = max_clock = intel_dp->link_rate_index - 1; > > 1. Why is min_clock same as max_clock? This forces the clock to a value > instead of iterating it based on the mode rate. > > 2. Why is min_lane_count set to max_lane_count? Is this done to be Spec > compliant? > > 3. What about bpp? Looks like the we will still be iterating over bpp to > find the link rate. > > -DK > > + intel_dp->link_train_failed_link_rate = 0; > > + intel_dp->link_rate_index = -1; > > + } > > + > > DRM_DEBUG_KMS("DP link computation with max lane count %i " > > "max bw %d pixel clock %iKHz\n", > > max_lane_count, common_rates[max_clock], > > @@ -5689,6 +5717,39 @@ static bool intel_edp_init_connector(struct intel_dp *intel_dp, > > return false; > > } > > > > +static void intel_dp_modeset_retry_work_fn(struct work_struct *work) > > +{ > > + struct drm_connector *connector; > > + struct intel_dp *intel_dp; > > + struct drm_display_mode *mode; > > + bool verbose_prune = true; > > + bool reprobe = false; > > + > > + connector = container_of(work, typeof(*connector), > > + i915_modeset_retry_work); > > + intel_dp = intel_attached_dp(connector); > > + > > + /* Grab the locks before changing connector property*/ > > + mutex_lock(&connector->dev->mode_config.mutex); > > + DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id, > > + connector->name); > > + list_for_each_entry(mode, &connector->modes, head) { > > + mode->status = intel_dp_mode_valid(connector, > > + mode); > > + if (mode->status != MODE_OK) > > + reprobe = true; > > + } > > + drm_mode_prune_invalid(connector->dev, &connector->modes, > > + verbose_prune); > > + mutex_unlock(&connector->dev->mode_config.mutex); > > + if (reprobe) { > > + /* Send Hotplug uevent so userspace can reprobe */ > > + drm_kms_helper_hotplug_event(connector->dev); > > + } > > + if (intel_dp->link_train_failed) > > + drm_atomic_helper_connector_modeset(connector); > > +} > > + > > bool > > intel_dp_init_connector(struct intel_digital_port *intel_dig_port, > > struct intel_connector *intel_connector) > > @@ -5701,6 +5762,10 @@ static bool intel_edp_init_connector(struct intel_dp *intel_dp, > > enum port port = intel_dig_port->port; > > int type; > > > > + /* Initialize the work for modeset in case of link train failure */ > > + INIT_WORK(&connector->i915_modeset_retry_work, > > + intel_dp_modeset_retry_work_fn); > > + > > if (WARN(intel_dig_port->max_lanes < 1, > > "Not enough lanes (%d) for DP on port %c\n", > > intel_dig_port->max_lanes, port_name(port))) > > diff --git a/drivers/gpu/drm/i915/intel_dp_link_training.c b/drivers/gpu/drm/i915/intel_dp_link_training.c > > index 0048b52..10f81ab 100644 > > --- a/drivers/gpu/drm/i915/intel_dp_link_training.c > > +++ b/drivers/gpu/drm/i915/intel_dp_link_training.c > > @@ -310,9 +310,15 @@ void intel_dp_stop_link_train(struct intel_dp *intel_dp) > > DP_TRAINING_PATTERN_DISABLE); > > } > > > > -void > > +bool > > intel_dp_start_link_train(struct intel_dp *intel_dp) > > { > > - intel_dp_link_training_clock_recovery(intel_dp); > > - intel_dp_link_training_channel_equalization(intel_dp); > > + bool ret; > > + > > + if (intel_dp_link_training_clock_recovery(intel_dp)) { > > + ret = intel_dp_link_training_channel_equalization(intel_dp); > > + if (ret) > > + return true; > > + } > > + return false; > > } > > diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h > > index 4e90b07..d3fcffc 100644 > > --- a/drivers/gpu/drm/i915/intel_drv.h > > +++ b/drivers/gpu/drm/i915/intel_drv.h > > @@ -890,6 +890,10 @@ struct intel_dp { > > uint32_t DP; > > int link_rate; > > uint8_t lane_count; > > + int link_train_failed_link_rate; > > + uint8_t link_train_failed_lane_count; > > + int link_rate_index; > > + bool link_train_failed; > > uint8_t sink_count; > > bool link_mst; > > bool has_audio; > > @@ -1394,7 +1398,7 @@ bool intel_dp_init_connector(struct intel_digital_port *intel_dig_port, > > void intel_dp_set_link_params(struct intel_dp *intel_dp, > > int link_rate, uint8_t lane_count, > > bool link_mst); > > -void intel_dp_start_link_train(struct intel_dp *intel_dp); > > +bool intel_dp_start_link_train(struct intel_dp *intel_dp); > > void intel_dp_stop_link_train(struct intel_dp *intel_dp); > > void intel_dp_sink_dpms(struct intel_dp *intel_dp, int mode); > > void intel_dp_encoder_reset(struct drm_encoder *encoder); >
On Tue, Oct 25, 2016 at 03:17:47PM +0300, Jani Nikula wrote: > On Sat, 22 Oct 2016, Manasi Navare <manasi.d.navare@intel.com> wrote: > > If link training at a link rate optimal for a particular > > mode fails during modeset's atomic commit phase, then we > > let the modeset complete and then retry. We save the link rate > > value at which link training failed and use a lower link rate > > to prune the modes. It will redo the modeset on the current mode > > at lower link rate or if the current mode gets pruned due to lower > > link constraints then, it will send a hotplug uevent for userspace > > to handle it. > > > > This is also required to pass DP CTS tests 4.3.1.3, 4.3.1.4, > > 4.3.1.6. > > > > Cc: Jani Nikula <jani.nikula@linux.intel.com> > > Cc: Daniel Vetter <daniel.vetter@intel.com> > > Cc: Ville Syrjala <ville.syrjala@linux.intel.com> > > Signed-off-by: Manasi Navare <manasi.d.navare@intel.com> > > --- > > drivers/gpu/drm/i915/intel_ddi.c | 15 +++++- > > drivers/gpu/drm/i915/intel_dp.c | 69 ++++++++++++++++++++++++++- > > drivers/gpu/drm/i915/intel_dp_link_training.c | 12 +++-- > > drivers/gpu/drm/i915/intel_drv.h | 6 ++- > > 4 files changed, 95 insertions(+), 7 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c > > index fb18d69..451433b 100644 > > --- a/drivers/gpu/drm/i915/intel_ddi.c > > +++ b/drivers/gpu/drm/i915/intel_ddi.c > > @@ -1712,6 +1712,8 @@ static void intel_ddi_pre_enable_dp(struct intel_encoder *encoder, > > struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base); > > struct drm_i915_private *dev_priv = to_i915(encoder->base.dev); > > enum port port = intel_ddi_get_encoder_port(encoder); > > + struct intel_connector *intel_connector = intel_dp->attached_connector; > > + struct drm_connector *connector = &intel_connector->base; > > > > intel_dp_set_link_params(intel_dp, link_rate, lane_count, > > link_mst); > > @@ -1722,7 +1724,18 @@ static void intel_ddi_pre_enable_dp(struct intel_encoder *encoder, > > intel_prepare_dp_ddi_buffers(encoder); > > intel_ddi_init_dp_buf_reg(encoder); > > intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON); > > - intel_dp_start_link_train(intel_dp); > > + if (!intel_dp_start_link_train(intel_dp)) { > > + DRM_ERROR("Link Training failed at link rate = %d, lane count = %d\n", > > + link_rate, lane_count); > > + intel_dp->link_train_failed = true; > > + intel_dp->link_train_failed_link_rate = link_rate; > > + intel_dp->link_train_failed_lane_count = lane_count; > > I think eventually you'll need to store a list (array) of failing link > rate, lane count pairs, not just the last that failed. Now you restrict > the link config computation to only reducing the link rate. But > currently (for whatever reason, it's flip-flopped too many times) we > start with wide & slow, meaning that in many cases we've already > exhausted the option to go slower. If optimal fails, maybe we need to > try narrow & fast instead. > > BR, > Jani. > > So the DP 1.2 spec says that we need to first try reducing the link rate all the way to RBR without reducing the lane count and if that fails then just fail the link training. DP spec 1.3 also reduces the lane count after reducing the link rate all the way to RBR, then it should try lower lane count and highest link rate again. But I havent expanded this to include spec 1.3 yet, this can be added later. The DP compliance only follows CTS according tO DP Spec 1.2 and they would be including lane count reduction later for CTS 1.3. But in either case I dont think we need an array, at link train failure, we just need to know the failed link rate and lane count based on which the next lower link rate/lane count value can be decided here during mode validation and be used during compute config. Manasi > > + /* Schedule a Hotplug Uevent to userspace to start modeset */ > > + schedule_work(&connector->i915_modeset_retry_work); > > + } else { > > + intel_dp->link_train_failed = false; > > + } > > + > > if (port != PORT_A || INTEL_GEN(dev_priv) >= 9) > > intel_dp_stop_link_train(intel_dp); > > } > > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c > > index c192e18..5d5f4a7 100644 > > --- a/drivers/gpu/drm/i915/intel_dp.c > > +++ b/drivers/gpu/drm/i915/intel_dp.c > > @@ -313,6 +313,7 @@ static int intel_dp_link_rate_index(struct intel_dp *intel_dp, > > int target_clock = mode->clock; > > int max_rate, mode_rate, max_lanes, max_link_clock; > > int max_dotclk; > > + int common_rates[DP_MAX_SUPPORTED_RATES] = {}; > > > > max_dotclk = intel_dp_downstream_max_dotclock(intel_dp); > > > > @@ -326,8 +327,27 @@ static int intel_dp_link_rate_index(struct intel_dp *intel_dp, > > target_clock = fixed_mode->clock; > > } > > > > - max_link_clock = intel_dp_max_link_rate(intel_dp); > > - max_lanes = intel_dp_max_lane_count(intel_dp); > > + /* Prune the modes based on the link rate that failed */ > > + if (intel_dp->link_train_failed_link_rate) { > > + intel_dp->link_rate_index = intel_dp_link_rate_index(intel_dp, > > + common_rates, > > + intel_dp->link_train_failed_link_rate); > > + if (intel_dp->link_rate_index > 0) { > > + max_link_clock = common_rates[intel_dp->link_rate_index - 1]; > > + max_lanes = intel_dp_max_lane_count(intel_dp); > > + } else { > > + /* Here we can lower the lane count, but that will be > > + * added for DP Spec 1.3 > > + */ > > + DRM_ERROR("No Valid Mode Supported for this Link\n"); > > + intel_dp->link_train_failed_link_rate = 0; > > + intel_dp->link_rate_index = -1; > > + intel_dp->link_train_failed = false; > > + } > > + } else { > > + max_link_clock = intel_dp_max_link_rate(intel_dp); > > + max_lanes = intel_dp_max_lane_count(intel_dp); > > + } > > > > max_rate = intel_dp_max_data_rate(max_link_clock, max_lanes); > > mode_rate = intel_dp_link_required(target_clock, 18); > > @@ -1619,6 +1639,14 @@ static int intel_dp_compute_bpp(struct intel_dp *intel_dp, > > if (adjusted_mode->flags & DRM_MODE_FLAG_DBLCLK) > > return false; > > > > + /* Fall back to lower link rate in case of failure in previous modeset */ > > + if (intel_dp->link_train_failed_link_rate) { > > + min_lane_count = max_lane_count; > > + min_clock = max_clock = intel_dp->link_rate_index - 1; > > + intel_dp->link_train_failed_link_rate = 0; > > + intel_dp->link_rate_index = -1; > > + } > > + > > DRM_DEBUG_KMS("DP link computation with max lane count %i " > > "max bw %d pixel clock %iKHz\n", > > max_lane_count, common_rates[max_clock], > > @@ -5689,6 +5717,39 @@ static bool intel_edp_init_connector(struct intel_dp *intel_dp, > > return false; > > } > > > > +static void intel_dp_modeset_retry_work_fn(struct work_struct *work) > > +{ > > + struct drm_connector *connector; > > + struct intel_dp *intel_dp; > > + struct drm_display_mode *mode; > > + bool verbose_prune = true; > > + bool reprobe = false; > > + > > + connector = container_of(work, typeof(*connector), > > + i915_modeset_retry_work); > > + intel_dp = intel_attached_dp(connector); > > + > > + /* Grab the locks before changing connector property*/ > > + mutex_lock(&connector->dev->mode_config.mutex); > > + DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id, > > + connector->name); > > + list_for_each_entry(mode, &connector->modes, head) { > > + mode->status = intel_dp_mode_valid(connector, > > + mode); > > + if (mode->status != MODE_OK) > > + reprobe = true; > > + } > > + drm_mode_prune_invalid(connector->dev, &connector->modes, > > + verbose_prune); > > + mutex_unlock(&connector->dev->mode_config.mutex); > > + if (reprobe) { > > + /* Send Hotplug uevent so userspace can reprobe */ > > + drm_kms_helper_hotplug_event(connector->dev); > > + } > > + if (intel_dp->link_train_failed) > > + drm_atomic_helper_connector_modeset(connector); > > +} > > + > > bool > > intel_dp_init_connector(struct intel_digital_port *intel_dig_port, > > struct intel_connector *intel_connector) > > @@ -5701,6 +5762,10 @@ static bool intel_edp_init_connector(struct intel_dp *intel_dp, > > enum port port = intel_dig_port->port; > > int type; > > > > + /* Initialize the work for modeset in case of link train failure */ > > + INIT_WORK(&connector->i915_modeset_retry_work, > > + intel_dp_modeset_retry_work_fn); > > + > > if (WARN(intel_dig_port->max_lanes < 1, > > "Not enough lanes (%d) for DP on port %c\n", > > intel_dig_port->max_lanes, port_name(port))) > > diff --git a/drivers/gpu/drm/i915/intel_dp_link_training.c b/drivers/gpu/drm/i915/intel_dp_link_training.c > > index 0048b52..10f81ab 100644 > > --- a/drivers/gpu/drm/i915/intel_dp_link_training.c > > +++ b/drivers/gpu/drm/i915/intel_dp_link_training.c > > @@ -310,9 +310,15 @@ void intel_dp_stop_link_train(struct intel_dp *intel_dp) > > DP_TRAINING_PATTERN_DISABLE); > > } > > > > -void > > +bool > > intel_dp_start_link_train(struct intel_dp *intel_dp) > > { > > - intel_dp_link_training_clock_recovery(intel_dp); > > - intel_dp_link_training_channel_equalization(intel_dp); > > + bool ret; > > + > > + if (intel_dp_link_training_clock_recovery(intel_dp)) { > > + ret = intel_dp_link_training_channel_equalization(intel_dp); > > + if (ret) > > + return true; > > + } > > + return false; > > } > > diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h > > index 4e90b07..d3fcffc 100644 > > --- a/drivers/gpu/drm/i915/intel_drv.h > > +++ b/drivers/gpu/drm/i915/intel_drv.h > > @@ -890,6 +890,10 @@ struct intel_dp { > > uint32_t DP; > > int link_rate; > > uint8_t lane_count; > > + int link_train_failed_link_rate; > > + uint8_t link_train_failed_lane_count; > > + int link_rate_index; > > + bool link_train_failed; > > uint8_t sink_count; > > bool link_mst; > > bool has_audio; > > @@ -1394,7 +1398,7 @@ bool intel_dp_init_connector(struct intel_digital_port *intel_dig_port, > > void intel_dp_set_link_params(struct intel_dp *intel_dp, > > int link_rate, uint8_t lane_count, > > bool link_mst); > > -void intel_dp_start_link_train(struct intel_dp *intel_dp); > > +bool intel_dp_start_link_train(struct intel_dp *intel_dp); > > void intel_dp_stop_link_train(struct intel_dp *intel_dp); > > void intel_dp_sink_dpms(struct intel_dp *intel_dp, int mode); > > void intel_dp_encoder_reset(struct drm_encoder *encoder); > > -- > Jani Nikula, Intel Open Source Technology Center
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c index fb18d69..451433b 100644 --- a/drivers/gpu/drm/i915/intel_ddi.c +++ b/drivers/gpu/drm/i915/intel_ddi.c @@ -1712,6 +1712,8 @@ static void intel_ddi_pre_enable_dp(struct intel_encoder *encoder, struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base); struct drm_i915_private *dev_priv = to_i915(encoder->base.dev); enum port port = intel_ddi_get_encoder_port(encoder); + struct intel_connector *intel_connector = intel_dp->attached_connector; + struct drm_connector *connector = &intel_connector->base; intel_dp_set_link_params(intel_dp, link_rate, lane_count, link_mst); @@ -1722,7 +1724,18 @@ static void intel_ddi_pre_enable_dp(struct intel_encoder *encoder, intel_prepare_dp_ddi_buffers(encoder); intel_ddi_init_dp_buf_reg(encoder); intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON); - intel_dp_start_link_train(intel_dp); + if (!intel_dp_start_link_train(intel_dp)) { + DRM_ERROR("Link Training failed at link rate = %d, lane count = %d\n", + link_rate, lane_count); + intel_dp->link_train_failed = true; + intel_dp->link_train_failed_link_rate = link_rate; + intel_dp->link_train_failed_lane_count = lane_count; + /* Schedule a Hotplug Uevent to userspace to start modeset */ + schedule_work(&connector->i915_modeset_retry_work); + } else { + intel_dp->link_train_failed = false; + } + if (port != PORT_A || INTEL_GEN(dev_priv) >= 9) intel_dp_stop_link_train(intel_dp); } diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index c192e18..5d5f4a7 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -313,6 +313,7 @@ static int intel_dp_link_rate_index(struct intel_dp *intel_dp, int target_clock = mode->clock; int max_rate, mode_rate, max_lanes, max_link_clock; int max_dotclk; + int common_rates[DP_MAX_SUPPORTED_RATES] = {}; max_dotclk = intel_dp_downstream_max_dotclock(intel_dp); @@ -326,8 +327,27 @@ static int intel_dp_link_rate_index(struct intel_dp *intel_dp, target_clock = fixed_mode->clock; } - max_link_clock = intel_dp_max_link_rate(intel_dp); - max_lanes = intel_dp_max_lane_count(intel_dp); + /* Prune the modes based on the link rate that failed */ + if (intel_dp->link_train_failed_link_rate) { + intel_dp->link_rate_index = intel_dp_link_rate_index(intel_dp, + common_rates, + intel_dp->link_train_failed_link_rate); + if (intel_dp->link_rate_index > 0) { + max_link_clock = common_rates[intel_dp->link_rate_index - 1]; + max_lanes = intel_dp_max_lane_count(intel_dp); + } else { + /* Here we can lower the lane count, but that will be + * added for DP Spec 1.3 + */ + DRM_ERROR("No Valid Mode Supported for this Link\n"); + intel_dp->link_train_failed_link_rate = 0; + intel_dp->link_rate_index = -1; + intel_dp->link_train_failed = false; + } + } else { + max_link_clock = intel_dp_max_link_rate(intel_dp); + max_lanes = intel_dp_max_lane_count(intel_dp); + } max_rate = intel_dp_max_data_rate(max_link_clock, max_lanes); mode_rate = intel_dp_link_required(target_clock, 18); @@ -1619,6 +1639,14 @@ static int intel_dp_compute_bpp(struct intel_dp *intel_dp, if (adjusted_mode->flags & DRM_MODE_FLAG_DBLCLK) return false; + /* Fall back to lower link rate in case of failure in previous modeset */ + if (intel_dp->link_train_failed_link_rate) { + min_lane_count = max_lane_count; + min_clock = max_clock = intel_dp->link_rate_index - 1; + intel_dp->link_train_failed_link_rate = 0; + intel_dp->link_rate_index = -1; + } + DRM_DEBUG_KMS("DP link computation with max lane count %i " "max bw %d pixel clock %iKHz\n", max_lane_count, common_rates[max_clock], @@ -5689,6 +5717,39 @@ static bool intel_edp_init_connector(struct intel_dp *intel_dp, return false; } +static void intel_dp_modeset_retry_work_fn(struct work_struct *work) +{ + struct drm_connector *connector; + struct intel_dp *intel_dp; + struct drm_display_mode *mode; + bool verbose_prune = true; + bool reprobe = false; + + connector = container_of(work, typeof(*connector), + i915_modeset_retry_work); + intel_dp = intel_attached_dp(connector); + + /* Grab the locks before changing connector property*/ + mutex_lock(&connector->dev->mode_config.mutex); + DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id, + connector->name); + list_for_each_entry(mode, &connector->modes, head) { + mode->status = intel_dp_mode_valid(connector, + mode); + if (mode->status != MODE_OK) + reprobe = true; + } + drm_mode_prune_invalid(connector->dev, &connector->modes, + verbose_prune); + mutex_unlock(&connector->dev->mode_config.mutex); + if (reprobe) { + /* Send Hotplug uevent so userspace can reprobe */ + drm_kms_helper_hotplug_event(connector->dev); + } + if (intel_dp->link_train_failed) + drm_atomic_helper_connector_modeset(connector); +} + bool intel_dp_init_connector(struct intel_digital_port *intel_dig_port, struct intel_connector *intel_connector) @@ -5701,6 +5762,10 @@ static bool intel_edp_init_connector(struct intel_dp *intel_dp, enum port port = intel_dig_port->port; int type; + /* Initialize the work for modeset in case of link train failure */ + INIT_WORK(&connector->i915_modeset_retry_work, + intel_dp_modeset_retry_work_fn); + if (WARN(intel_dig_port->max_lanes < 1, "Not enough lanes (%d) for DP on port %c\n", intel_dig_port->max_lanes, port_name(port))) diff --git a/drivers/gpu/drm/i915/intel_dp_link_training.c b/drivers/gpu/drm/i915/intel_dp_link_training.c index 0048b52..10f81ab 100644 --- a/drivers/gpu/drm/i915/intel_dp_link_training.c +++ b/drivers/gpu/drm/i915/intel_dp_link_training.c @@ -310,9 +310,15 @@ void intel_dp_stop_link_train(struct intel_dp *intel_dp) DP_TRAINING_PATTERN_DISABLE); } -void +bool intel_dp_start_link_train(struct intel_dp *intel_dp) { - intel_dp_link_training_clock_recovery(intel_dp); - intel_dp_link_training_channel_equalization(intel_dp); + bool ret; + + if (intel_dp_link_training_clock_recovery(intel_dp)) { + ret = intel_dp_link_training_channel_equalization(intel_dp); + if (ret) + return true; + } + return false; } diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h index 4e90b07..d3fcffc 100644 --- a/drivers/gpu/drm/i915/intel_drv.h +++ b/drivers/gpu/drm/i915/intel_drv.h @@ -890,6 +890,10 @@ struct intel_dp { uint32_t DP; int link_rate; uint8_t lane_count; + int link_train_failed_link_rate; + uint8_t link_train_failed_lane_count; + int link_rate_index; + bool link_train_failed; uint8_t sink_count; bool link_mst; bool has_audio; @@ -1394,7 +1398,7 @@ bool intel_dp_init_connector(struct intel_digital_port *intel_dig_port, void intel_dp_set_link_params(struct intel_dp *intel_dp, int link_rate, uint8_t lane_count, bool link_mst); -void intel_dp_start_link_train(struct intel_dp *intel_dp); +bool intel_dp_start_link_train(struct intel_dp *intel_dp); void intel_dp_stop_link_train(struct intel_dp *intel_dp); void intel_dp_sink_dpms(struct intel_dp *intel_dp, int mode); void intel_dp_encoder_reset(struct drm_encoder *encoder);
If link training at a link rate optimal for a particular mode fails during modeset's atomic commit phase, then we let the modeset complete and then retry. We save the link rate value at which link training failed and use a lower link rate to prune the modes. It will redo the modeset on the current mode at lower link rate or if the current mode gets pruned due to lower link constraints then, it will send a hotplug uevent for userspace to handle it. This is also required to pass DP CTS tests 4.3.1.3, 4.3.1.4, 4.3.1.6. Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Daniel Vetter <daniel.vetter@intel.com> Cc: Ville Syrjala <ville.syrjala@linux.intel.com> Signed-off-by: Manasi Navare <manasi.d.navare@intel.com> --- drivers/gpu/drm/i915/intel_ddi.c | 15 +++++- drivers/gpu/drm/i915/intel_dp.c | 69 ++++++++++++++++++++++++++- drivers/gpu/drm/i915/intel_dp_link_training.c | 12 +++-- drivers/gpu/drm/i915/intel_drv.h | 6 ++- 4 files changed, 95 insertions(+), 7 deletions(-)