[Intel-gfx] [PATCH 1/2] drm/i915: Add support for retrying hotplug

Imre Deak imre.deak at intel.com
Fri Mar 15 01:39:20 UTC 2019


On Fri, Mar 15, 2019 at 02:25:36AM +0200, Souza, Jose wrote:
> On Thu, 2019-03-14 at 18:09 +0200, Imre Deak wrote:
> > On Tue, Mar 12, 2019 at 05:58:51PM -0700, José Roberto de Souza
> > wrote:
> > > From: Imre Deak <imre.deak at intel.com>
> > > 
> > > There is some scenarios that we are aware that sink probe can fail,
> > > so lets add the infrastructure to let hotplug() hook to request
> > > another probe after some time.
> > > 
> > > Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > > Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
> > > Signed-off-by: Jani Nikula <jani.nikula at intel.com>
> > > Signed-off-by: Imre Deak <imre.deak at intel.com>
> > > ---
> > >  drivers/gpu/drm/i915/i915_debugfs.c  |  2 +-
> > >  drivers/gpu/drm/i915/i915_drv.h      |  3 +-
> > >  drivers/gpu/drm/i915/intel_ddi.c     | 12 +++---
> > >  drivers/gpu/drm/i915/intel_dp.c      | 12 +++---
> > >  drivers/gpu/drm/i915/intel_drv.h     | 17 +++++++--
> > >  drivers/gpu/drm/i915/intel_hotplug.c | 56 ++++++++++++++++++++++
> > > ------
> > >  drivers/gpu/drm/i915/intel_sdvo.c    |  8 ++--
> > >  7 files changed, 79 insertions(+), 31 deletions(-)
> > > 
> > > diff --git a/drivers/gpu/drm/i915/i915_debugfs.c
> > > b/drivers/gpu/drm/i915/i915_debugfs.c
> > > index 6a90558de213..f93aab165c7e 100644
> > > --- a/drivers/gpu/drm/i915/i915_debugfs.c
> > > +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> > > @@ -4289,7 +4289,7 @@ static int i915_hpd_storm_ctl_show(struct
> > > seq_file *m, void *data)
> > >  	 */
> > >  	synchronize_irq(dev_priv->drm.irq);
> > >  	flush_work(&dev_priv->hotplug.dig_port_work);
> > > -	flush_work(&dev_priv->hotplug.hotplug_work);
> > > +	flush_delayed_work(&dev_priv->hotplug.hotplug_work);
> > >  
> > >  	seq_printf(m, "Threshold: %d\n", hotplug->hpd_storm_threshold);
> > >  	seq_printf(m, "Detected: %s\n",
> > > diff --git a/drivers/gpu/drm/i915/i915_drv.h
> > > b/drivers/gpu/drm/i915/i915_drv.h
> > > index dc63303225fc..f47cec8b7f01 100644
> > > --- a/drivers/gpu/drm/i915/i915_drv.h
> > > +++ b/drivers/gpu/drm/i915/i915_drv.h
> > > @@ -156,7 +156,7 @@ enum hpd_pin {
> > >  #define HPD_STORM_DEFAULT_THRESHOLD 50
> > >  
> > >  struct i915_hotplug {
> > > -	struct work_struct hotplug_work;
> > > +	struct delayed_work hotplug_work;
> > >  
> > >  	struct {
> > >  		unsigned long last_jiffies;
> > > @@ -168,6 +168,7 @@ struct i915_hotplug {
> > >  		} state;
> > >  	} stats[HPD_NUM_PINS];
> > >  	u32 event_bits;
> > > +	u32 retry_bits;
> > >  	struct delayed_work reenable_work;
> > >  
> > >  	u32 long_port_mask;
> > > diff --git a/drivers/gpu/drm/i915/intel_ddi.c
> > > b/drivers/gpu/drm/i915/intel_ddi.c
> > > index 7e3b4e8fdf3a..5b840a5d00cc 100644
> > > --- a/drivers/gpu/drm/i915/intel_ddi.c
> > > +++ b/drivers/gpu/drm/i915/intel_ddi.c
> > > @@ -4053,14 +4053,16 @@ static int intel_hdmi_reset_link(struct
> > > intel_encoder *encoder,
> > >  	return modeset_pipe(&crtc->base, ctx);
> > >  }
> > >  
> > > -static bool intel_ddi_hotplug(struct intel_encoder *encoder,
> > > -			      struct intel_connector *connector)
> > > +static enum intel_hotplug_state
> > > +intel_ddi_hotplug(struct intel_encoder *encoder,
> > > +		  struct intel_connector *connector,
> > > +		  bool irq_received)
> > >  {
> > >  	struct drm_modeset_acquire_ctx ctx;
> > > -	bool changed;
> > > +	enum intel_hotplug_state state;
> > >  	int ret;
> > >  
> > > -	changed = intel_encoder_hotplug(encoder, connector);
> > > +	state = intel_encoder_hotplug(encoder, connector,
> > > irq_received);
> > >  
> > >  	drm_modeset_acquire_init(&ctx, 0);
> > >  
> > > @@ -4082,7 +4084,7 @@ static bool intel_ddi_hotplug(struct
> > > intel_encoder *encoder,
> > >  	drm_modeset_acquire_fini(&ctx);
> > >  	WARN(ret, "Acquiring modeset locks failed with %i\n", ret);
> > >  
> > > -	return changed;
> > > +	return state;
> > >  }
> > >  
> > >  static struct intel_connector *
> > > diff --git a/drivers/gpu/drm/i915/intel_dp.c
> > > b/drivers/gpu/drm/i915/intel_dp.c
> > > index f40b3342d82a..f74e72173874 100644
> > > --- a/drivers/gpu/drm/i915/intel_dp.c
> > > +++ b/drivers/gpu/drm/i915/intel_dp.c
> > > @@ -4738,14 +4738,16 @@ int intel_dp_retrain_link(struct
> > > intel_encoder *encoder,
> > >   * retrain the link to get a picture. That's in case no
> > >   * userspace component reacted to intermittent HPD dip.
> > >   */
> > > -static bool intel_dp_hotplug(struct intel_encoder *encoder,
> > > -			     struct intel_connector *connector)
> > > +static enum intel_hotplug_state
> > > +intel_dp_hotplug(struct intel_encoder *encoder,
> > > +		 struct intel_connector *connector,
> > > +		 bool irq_received)
> > >  {
> > >  	struct drm_modeset_acquire_ctx ctx;
> > > -	bool changed;
> > > +	enum intel_hotplug_state state;
> > >  	int ret;
> > >  
> > > -	changed = intel_encoder_hotplug(encoder, connector);
> > > +	state = intel_encoder_hotplug(encoder, connector,
> > > irq_received);
> > >  
> > >  	drm_modeset_acquire_init(&ctx, 0);
> > >  
> > > @@ -4764,7 +4766,7 @@ static bool intel_dp_hotplug(struct
> > > intel_encoder *encoder,
> > >  	drm_modeset_acquire_fini(&ctx);
> > >  	WARN(ret, "Acquiring modeset locks failed with %i\n", ret);
> > >  
> > > -	return changed;
> > > +	return state;
> > >  }
> > >  
> > >  static void intel_dp_check_service_irq(struct intel_dp *intel_dp)
> > > diff --git a/drivers/gpu/drm/i915/intel_drv.h
> > > b/drivers/gpu/drm/i915/intel_drv.h
> > > index 40ebc94b2187..be9fe0268472 100644
> > > --- a/drivers/gpu/drm/i915/intel_drv.h
> > > +++ b/drivers/gpu/drm/i915/intel_drv.h
> > > @@ -226,14 +226,21 @@ struct intel_fbdev {
> > >  	struct mutex hpd_lock;
> > >  };
> > >  
> > > +enum intel_hotplug_state {
> > > +	INTEL_HOTPLUG_NOCHANGE,
> > > +	INTEL_HOTPLUG_CHANGED,
> > > +	INTEL_HOTPLUG_RETRY,
> > > +};
> > > +
> > >  struct intel_encoder {
> > >  	struct drm_encoder base;
> > >  
> > >  	enum intel_output_type type;
> > >  	enum port port;
> > >  	unsigned int cloneable;
> > > -	bool (*hotplug)(struct intel_encoder *encoder,
> > > -			struct intel_connector *connector);
> > > +	enum intel_hotplug_state (*hotplug)(struct intel_encoder
> > > *encoder,
> > > +					    struct intel_connector
> > > *connector,
> > > +					    bool irq_received);
> > >  	enum intel_output_type (*compute_output_type)(struct
> > > intel_encoder *,
> > >  						      struct
> > > intel_crtc_state *,
> > >  						      struct
> > > drm_connector_state *);
> > > @@ -2016,8 +2023,10 @@ int
> > > intel_dsi_dcs_init_backlight_funcs(struct intel_connector
> > > *intel_connector);
> > >  void intel_dvo_init(struct drm_i915_private *dev_priv);
> > >  /* intel_hotplug.c */
> > >  void intel_hpd_poll_init(struct drm_i915_private *dev_priv);
> > > -bool intel_encoder_hotplug(struct intel_encoder *encoder,
> > > -			   struct intel_connector *connector);
> > > +enum intel_hotplug_state
> > > +intel_encoder_hotplug(struct intel_encoder *encoder,
> > > +		      struct intel_connector *connector,
> > > +		      bool irq_received);
> > >  
> > >  /* legacy fbdev emulation in intel_fbdev.c */
> > >  #ifdef CONFIG_DRM_FBDEV_EMULATION
> > > diff --git a/drivers/gpu/drm/i915/intel_hotplug.c
> > > b/drivers/gpu/drm/i915/intel_hotplug.c
> > > index b8937c788f03..3eaa06526f6b 100644
> > > --- a/drivers/gpu/drm/i915/intel_hotplug.c
> > > +++ b/drivers/gpu/drm/i915/intel_hotplug.c
> > > @@ -111,6 +111,7 @@ enum hpd_pin intel_hpd_pin_default(struct
> > > drm_i915_private *dev_priv,
> > >  
> > >  #define HPD_STORM_DETECT_PERIOD		1000
> > >  #define HPD_STORM_REENABLE_DELAY	(2 * 60 * 1000)
> > > +#define HPD_RETRY_DELAY			1000
> > >  
> > >  /**
> > >   * intel_hpd_irq_storm_detect - gather stats and detect HPD IRQ
> > > storm on a pin
> > > @@ -265,8 +266,10 @@ static void
> > > intel_hpd_irq_storm_reenable_work(struct work_struct *work)
> > >  	intel_runtime_pm_put(dev_priv, wakeref);
> > >  }
> > >  
> > > -bool intel_encoder_hotplug(struct intel_encoder *encoder,
> > > -			   struct intel_connector *connector)
> > > +enum intel_hotplug_state
> > > +intel_encoder_hotplug(struct intel_encoder *encoder,
> > > +		      struct intel_connector *connector,
> > > +		      bool irq_received)
> > >  {
> > >  	struct drm_device *dev = connector->base.dev;
> > >  	enum drm_connector_status old_status;
> > > @@ -278,7 +281,7 @@ bool intel_encoder_hotplug(struct intel_encoder
> > > *encoder,
> > >  		drm_helper_probe_detect(&connector->base, NULL, false);
> > >  
> > >  	if (old_status == connector->base.status)
> > > -		return false;
> > > +		return INTEL_HOTPLUG_NOCHANGE;
> > >  
> > >  	DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to
> > > %s\n",
> > >  		      connector->base.base.id,
> > > @@ -286,7 +289,7 @@ bool intel_encoder_hotplug(struct intel_encoder
> > > *encoder,
> > >  		      drm_get_connector_status_name(old_status),
> > >  		      drm_get_connector_status_name(connector-
> > > >base.status));
> > >  
> > > -	return true;
> > > +	return INTEL_HOTPLUG_CHANGED;
> > >  }
> > >  
> > >  static bool intel_encoder_has_hpd_pulse(struct intel_encoder
> > > *encoder)
> > > @@ -338,7 +341,7 @@ static void i915_digport_work_func(struct
> > > work_struct *work)
> > >  		spin_lock_irq(&dev_priv->irq_lock);
> > >  		dev_priv->hotplug.event_bits |= old_bits;
> > >  		spin_unlock_irq(&dev_priv->irq_lock);
> > > -		schedule_work(&dev_priv->hotplug.hotplug_work);
> > > +		schedule_delayed_work(&dev_priv->hotplug.hotplug_work,
> > > 0);
> > >  	}
> > >  }
> > >  
> > > @@ -348,14 +351,17 @@ static void i915_digport_work_func(struct
> > > work_struct *work)
> > >  static void i915_hotplug_work_func(struct work_struct *work)
> > >  {
> > >  	struct drm_i915_private *dev_priv =
> > > -		container_of(work, struct drm_i915_private,
> > > hotplug.hotplug_work);
> > > +		container_of(work, struct drm_i915_private,
> > > +			     hotplug.hotplug_work.work);
> > >  	struct drm_device *dev = &dev_priv->drm;
> > >  	struct intel_connector *intel_connector;
> > >  	struct intel_encoder *intel_encoder;
> > >  	struct drm_connector *connector;
> > >  	struct drm_connector_list_iter conn_iter;
> > >  	bool changed = false;
> > > +	u32 retry = 0;
> > >  	u32 hpd_event_bits;
> > > +	u32 hpd_retry_bits;
> > >  
> > >  	mutex_lock(&dev->mode_config.mutex);
> > >  	DRM_DEBUG_KMS("running encoder hotplug functions\n");
> > > @@ -364,6 +370,8 @@ static void i915_hotplug_work_func(struct
> > > work_struct *work)
> > >  
> > >  	hpd_event_bits = dev_priv->hotplug.event_bits;
> > >  	dev_priv->hotplug.event_bits = 0;
> > > +	hpd_retry_bits = dev_priv->hotplug.retry_bits;
> > > +	dev_priv->hotplug.retry_bits = 0;
> > >  
> > >  	/* Enable polling for connectors which had HPD IRQ storms */
> > >  	intel_hpd_irq_storm_switch_to_polling(dev_priv);
> > > @@ -372,16 +380,29 @@ static void i915_hotplug_work_func(struct
> > > work_struct *work)
> > >  
> > >  	drm_connector_list_iter_begin(dev, &conn_iter);
> > >  	drm_for_each_connector_iter(connector, &conn_iter) {
> > > +		u32 hpd_bit;
> > > +
> > >  		intel_connector = to_intel_connector(connector);
> > >  		if (!intel_connector->encoder)
> > >  			continue;
> > >  		intel_encoder = intel_connector->encoder;
> > > -		if (hpd_event_bits & (1 << intel_encoder->hpd_pin)) {
> > > +		hpd_bit = BIT(intel_encoder->hpd_pin);
> > > +		if ((hpd_event_bits | hpd_retry_bits) & hpd_bit) {
> > >  			DRM_DEBUG_KMS("Connector %s (pin %i) received
> > > hotplug event.\n",
> > >  				      connector->name, intel_encoder-
> > > >hpd_pin);
> > >  
> > > -			changed |= intel_encoder-
> > > >hotplug(intel_encoder,
> > > -							  intel_connect
> > > or);
> > > +			switch (intel_encoder->hotplug(intel_encoder,
> > > +						       intel_connector,
> > > +						       hpd_event_bits &
> > > hpd_bit)) {
> > > +			case INTEL_HOTPLUG_NOCHANGE:
> > > +				break;
> > > +			case INTEL_HOTPLUG_CHANGED:
> > > +				changed = true;
> > > +				break;
> > > +			case INTEL_HOTPLUG_RETRY:
> > > +				retry |= hpd_bit;
> > > +				break;
> > > +			}
> > >  		}
> > >  	}
> > >  	drm_connector_list_iter_end(&conn_iter);
> > > @@ -389,6 +410,15 @@ static void i915_hotplug_work_func(struct
> > > work_struct *work)
> > >  
> > >  	if (changed)
> > >  		drm_kms_helper_hotplug_event(dev);
> > 
> > Just realized, that this way we'll do hotplug processing for pins
> > with a
> > shared encoder (DDI DP/HDMI) twice, even if one encoder's hotplug
> > hook
> > signaled a change (and so there can't be any change on other
> > connectors
> > sharing this encoder). I suppose preventing calling the hook for a
> > pin that
> > already signalled a change would make sense, but that's a separate
> > issue and could still lead to retrying needlessly. So I think we
> > should
> > prevent the retry here explicitly:
> > 
> > 	retry &= ~changed;
> 
> I was not aware of this shared hotplug pin, but it will need more than
> that, if the first port sharing a pin have changed but the second don't
> it would still mark the pin to retry,

For two connectors sharing an encoder their ports and pins will be the same.
So if you do above:

		case INTEL_HOTPLUG_CHANGED:
			changed |= hpd_bit;
			break;

		...

you can just avoid the retries for such changed connectors by

	retry &= ~changed;
	
here.	


> I will fix that and add the
> "retry" to the hotplug DP handler of non-ddi platforms.
> 
> > 
> > (making changed a bitmap).
> > 
> > > +
> > > +	if (retry) {
> > > +		spin_lock_irq(&dev_priv->irq_lock);
> > > +		dev_priv->hotplug.retry_bits |= retry;
> > > +		spin_unlock_irq(&dev_priv->irq_lock);
> > > +
> > > +		mod_delayed_work(system_wq, &dev_priv-
> > > >hotplug.hotplug_work,
> > > +				 msecs_to_jiffies(HPD_RETRY_DELAY));
> > > +	}
> > >  }
> > >  
> > >  
> > > @@ -515,7 +545,7 @@ void intel_hpd_irq_handler(struct
> > > drm_i915_private *dev_priv,
> > >  	if (queue_dig)
> > >  		queue_work(dev_priv->hotplug.dp_wq, &dev_priv-
> > > >hotplug.dig_port_work);
> > >  	if (queue_hp)
> > > -		schedule_work(&dev_priv->hotplug.hotplug_work);
> > > +		schedule_delayed_work(&dev_priv->hotplug.hotplug_work,
> > > 0);
> > >  }
> > >  
> > >  /**
> > > @@ -635,7 +665,8 @@ void intel_hpd_poll_init(struct
> > > drm_i915_private *dev_priv)
> > >  
> > >  void intel_hpd_init_work(struct drm_i915_private *dev_priv)
> > >  {
> > > -	INIT_WORK(&dev_priv->hotplug.hotplug_work,
> > > i915_hotplug_work_func);
> > > +	INIT_DELAYED_WORK(&dev_priv->hotplug.hotplug_work,
> > > +			  i915_hotplug_work_func);
> > >  	INIT_WORK(&dev_priv->hotplug.dig_port_work,
> > > i915_digport_work_func);
> > >  	INIT_WORK(&dev_priv->hotplug.poll_init_work,
> > > i915_hpd_poll_init_work);
> > >  	INIT_DELAYED_WORK(&dev_priv->hotplug.reenable_work,
> > > @@ -649,11 +680,12 @@ void intel_hpd_cancel_work(struct
> > > drm_i915_private *dev_priv)
> > >  	dev_priv->hotplug.long_port_mask = 0;
> > >  	dev_priv->hotplug.short_port_mask = 0;
> > >  	dev_priv->hotplug.event_bits = 0;
> > > +	dev_priv->hotplug.retry_bits = 0;
> > >  
> > >  	spin_unlock_irq(&dev_priv->irq_lock);
> > >  
> > >  	cancel_work_sync(&dev_priv->hotplug.dig_port_work);
> > > -	cancel_work_sync(&dev_priv->hotplug.hotplug_work);
> > > +	cancel_delayed_work_sync(&dev_priv->hotplug.hotplug_work);
> > >  	cancel_work_sync(&dev_priv->hotplug.poll_init_work);
> > >  	cancel_delayed_work_sync(&dev_priv->hotplug.reenable_work);
> > >  }
> > > diff --git a/drivers/gpu/drm/i915/intel_sdvo.c
> > > b/drivers/gpu/drm/i915/intel_sdvo.c
> > > index 68f497493d43..05ae7b3704a7 100644
> > > --- a/drivers/gpu/drm/i915/intel_sdvo.c
> > > +++ b/drivers/gpu/drm/i915/intel_sdvo.c
> > > @@ -1838,12 +1838,14 @@ static void
> > > intel_sdvo_enable_hotplug(struct intel_encoder *encoder)
> > >  			     &intel_sdvo->hotplug_active, 2);
> > >  }
> > >  
> > > -static bool intel_sdvo_hotplug(struct intel_encoder *encoder,
> > > -			       struct intel_connector *connector)
> > > +static enum intel_hotplug_state
> > > +intel_sdvo_hotplug(struct intel_encoder *encoder,
> > > +		   struct intel_connector *connector,
> > > +		   bool irq_received)
> > >  {
> > >  	intel_sdvo_enable_hotplug(encoder);
> > >  
> > > -	return intel_encoder_hotplug(encoder, connector);
> > > +	return intel_encoder_hotplug(encoder, connector, irq_received);
> > >  }
> > >  
> > >  static bool
> > > -- 
> > > 2.21.0
> > > 




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