[Intel-gfx] [PATCH 2/3] drm/i915/icl: Fix TypeC legacy HDMI HPD handling

[Imre Deak]

On Fri, Dec 14, 2018 at 02:22:09PM -0800, Rodrigo Vivi wrote:
> On Fri, Dec 14, 2018 at 01:25:07AM +0200, Imre Deak wrote:
> > On Thu, Dec 13, 2018 at 01:06:51PM -0800, Rodrigo Vivi wrote:
> > > On Thu, Dec 13, 2018 at 09:48:49PM +0200, Imre Deak wrote:
> > > > Atm HPD disconnect events on TypeC ports will break things, since we'll
> > > > switch the TypeC mode (between Legacy and disconnected modes as well as
> > > > among USB DP alternate, Thunderbolt alternate and disconnected modes) on
> > > > the fly from the HPD disconnect interrupt work while the port may be
> > > > still active.
> > > > 
> > > > Even if the port happens to be not active during the disconnect we'd
> > > > still have a problem during a subsequent modeset or AUX transfer that
> > > > could happen regardless of the port's connected state. For instance the
> > > > system resume display mode restore code and userspace could perform a
> > > > modeset on the port or userspace could start an AUX transfer even if the
> > > > port is in disconnected state.
> > > > 
> > > > To fix this keep legacy TypeC ports in TypeC legacy mode whenever we're
> > > > not suspended. The legacy mode is a static configuration as opposed to
> > > > the Thunderbolt and USB DP alternate modes between which we can switch
> > > > dynamically.
> > > > 
> > > > We don't have yet an explicit way to detect TypeC legacy ports, but we
> > > > can imply that at least in case of HDMI enabled ports, since HDMI can
> > > > only be provided in legacy mode. So mark TypeC HDMI enabled ports as
> > > > legacy and run the TypeC PHY connect sequence explicitly during driver
> > > > loading and system resume. The connect will succeed even if the display
> > > > is not connected to begin with (or disappears during the suspended
> > > > state) since for legacy ports the PORT_TX_DFLEXDPPMS /
> > > > DP_PHY_MODE_STATUS_COMPLETED flag is always set (as opposed to the USB
> > > > DP alternate mode where it gets set only when a display is connected).
> > > > 
> > > > Correspondingly run the TypeC PHY disconnect sequence during system
> > > > suspend and driver unloading, but disconnect during suspend only for
> > > > legacy TypeC mode. We will need to disconnect even in USB DP alternate
> > > > mode in the future, but atm we don't have a way to reconnect the port
> > > > in this mode during resume if the display disappears while being
> > > > suspended. So for now punt on this case.
> > > > 
> > > > Note that we do not disconnect the port during runtime suspend; in
> > > > legacy mode there are no shared HW resources (PHY lanes) with other HW
> > > > blocks (USB), so no need to release / reacquire these resources as with
> > > > USB DP alternate mode. The only reason to disconnect legacy ports during
> > > > system suspend is that the PORT_TX_DFLEXDPPMS /
> > > > DP_PHY_MODE_STATUS_COMPLETED flag must be rechecked and the port must be
> > > > connected again during system resume. We may also need to turn the check
> > > > for this flag into a poll, depending on further tests and clarifications
> > > > we are expecting from HW/FW people.
> > > > 
> > > > If VBT says that the port provides only DP functionality then we can't
> > > > assume that it's a legacy port as for HDMI (since it could as well be
> > > > a TBT/DP Alt connector), so we'll solve HPD handling for the DP case
> > > > with a different method in the next patch.
> > > > 
> > > > Eventually - instead of the above method - we'll depend on an explicit
> > > > detection method provided either via a VBT flag or a FW/HW register both
> > > > for the HDMI and DP case.
> > > > 
> > > > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=108070
> > > > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=108924
> > > > Cc: Paulo Zanoni <paulo.r.zanoni at intel.com>
> > > > Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > > > Cc: José Roberto de Souza <jose.souza at intel.com>
> > > > Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> > > > Signed-off-by: Imre Deak <imre.deak at intel.com>
> > > > ---
> > > >  drivers/gpu/drm/i915/intel_ddi.c | 54 +++++++++++++++++++++++++++++++++++++---
> > > >  drivers/gpu/drm/i915/intel_dp.c  | 29 ++++++++++++++-------
> > > >  drivers/gpu/drm/i915/intel_drv.h |  5 +++-
> > > >  3 files changed, 75 insertions(+), 13 deletions(-)
> > > > 
> > > > diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
> > > > index f3e1d6a0b7dd..2e47ffa1c95a 100644
> > > > --- a/drivers/gpu/drm/i915/intel_ddi.c
> > > > +++ b/drivers/gpu/drm/i915/intel_ddi.c
> > > > @@ -3901,9 +3901,50 @@ static bool intel_ddi_compute_config(struct intel_encoder *encoder,
> > > >  
> > > >  }
> > > >  
> > > > +static void intel_ddi_encoder_suspend(struct intel_encoder *encoder)
> > > > +{
> > > > +	struct intel_digital_port *dig_port = enc_to_dig_port(&encoder->base);
> > > > +	struct drm_i915_private *i915 = to_i915(encoder->base.dev);
> > > > +
> > > > +	intel_dp_encoder_suspend(encoder);
> > > > +
> > > > +	/*
> > > > +	 * TODO: disconnect also from USB DP alternate mode once we have a
> > > > +	 * way to handle the modeset restore in that mode during resume
> > > > +	 * even if the sink has disappeared while being suspended.
> > > > +	 */
> > > > +	if (dig_port->tc_legacy_port)
> > > > +		icl_tc_phy_disconnect(i915, dig_port);
> > > > +}
> > > > +
> > > > +static void intel_ddi_encoder_reset(struct drm_encoder *drm_encoder)
> > > > +{
> > > > +	struct intel_digital_port *dig_port = enc_to_dig_port(drm_encoder);
> > > > +	struct drm_i915_private *i915 = to_i915(drm_encoder->dev);
> > > > +
> > > > +	if (intel_port_is_tc(i915, dig_port->base.port))
> > > > +		intel_digital_port_connected(&dig_port->base);
> > > > +
> > > > +	intel_dp_encoder_reset(drm_encoder);
> > > 
> > > do we need all of that?
> > 
> > You mean if we need to call intel_dp_encoder_reset()? That was the
> > original state, as before this change we had
> 
> yes.
> 
> > 
> > 	.reset = intel_dp_encoder_reset
> > 
> > in intel_ddi_funcs. 
> > 
> > > or could simply
> > > 
> > > intel_dp->reset_link_params = true;
> > > 
> > > instead?! 
> > 
> > Not sure how we could avoid calling intel_dp_encoder_reset() here, it
> > has required LSPCON and eDP specific parts.
> 
> I had in my mind the type_c only, sorry.
> 
> But now what I don't understand is why we don't need to do the same
> and call intel_dp_encoder_destroy from inside intel_ddi_encoder_destroy.
> it seems that we will loose some LSPCON and eDP there as well...

That stuff moved to intel_dp_encoder_flush_work() as explained below,
which is called from intel_ddi_encoder_destroy().

> 
> > 
> > > 
> > > > +}
> > > > +
> > > > +static void intel_ddi_encoder_destroy(struct drm_encoder *encoder)
> > > > +{
> > > > +	struct intel_digital_port *dig_port = enc_to_dig_port(encoder);
> > > > +	struct drm_i915_private *i915 = to_i915(encoder->dev);
> > > > +
> > > > +	intel_dp_encoder_flush_work(encoder);
> > > > +
> > > > +	if (intel_port_is_tc(i915, dig_port->base.port))
> > > > +		icl_tc_phy_disconnect(i915, dig_port);
> > > > +
> > > > +	drm_encoder_cleanup(encoder);
> > > 
> > > and here don't we need stuff on intel_dp_encoder destroy here like
> > > intel_dp_aux_fini?
> > 
> > Yes we do, that's part of the new intel_dp_encoder_flush_work() func.
> > Had to split up intel_dp_encoder_destroy(), since we want to flush any
> > pending work on the encoder first (for instance MST specific stuff) then
> > disconnect the TC PHY, then do the DRM core cleanup and kfree. Probably
> > should've been in the commit log.
> > 
> > > 
> > > > +	kfree(dig_port);
> > > > +}
> > > > +
> > > >  static const struct drm_encoder_funcs intel_ddi_funcs = {
> > > > -	.reset = intel_dp_encoder_reset,
> > > > -	.destroy = intel_dp_encoder_destroy,
> > > > +	.reset = intel_ddi_encoder_reset,
> > > > +	.destroy = intel_ddi_encoder_destroy,
> > > >  };
> > > >  
> > > >  static struct intel_connector *
> > > > @@ -4197,7 +4238,7 @@ void intel_ddi_init(struct drm_i915_private *dev_priv, enum port port)
> > > >  	intel_encoder->post_disable = intel_ddi_post_disable;
> > > >  	intel_encoder->get_hw_state = intel_ddi_get_hw_state;
> > > >  	intel_encoder->get_config = intel_ddi_get_config;
> > > > -	intel_encoder->suspend = intel_dp_encoder_suspend;
> > > > +	intel_encoder->suspend = intel_ddi_encoder_suspend;
> > > >  	intel_encoder->get_power_domains = intel_ddi_get_power_domains;
> > > >  	intel_encoder->type = INTEL_OUTPUT_DDI;
> > > >  	intel_encoder->power_domain = intel_port_to_power_domain(port);
> > > > @@ -4257,6 +4298,9 @@ void intel_ddi_init(struct drm_i915_private *dev_priv, enum port port)
> > > >  	if (intel_encoder->type != INTEL_OUTPUT_EDP && init_hdmi) {
> > > >  		if (!intel_ddi_init_hdmi_connector(intel_dig_port))
> > > >  			goto err;
> > > > +
> > > > +		if (intel_port_is_tc(dev_priv, port))
> > > > +			intel_dig_port->tc_legacy_port = true;
> > > >  	}
> > > >  
> > > >  	if (init_lspcon) {
> > > > @@ -4274,6 +4318,10 @@ void intel_ddi_init(struct drm_i915_private *dev_priv, enum port port)
> > > >  	}
> > > >  
> > > >  	intel_infoframe_init(intel_dig_port);
> > > > +
> > > > +	if (intel_port_is_tc(dev_priv, port))
> > > > +		intel_digital_port_connected(intel_encoder);
> > > > +
> > > >  	return;
> > > >  
> > > >  err:
> > > > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> > > > index 082594bb65a7..19e49adab548 100644
> > > > --- a/drivers/gpu/drm/i915/intel_dp.c
> > > > +++ b/drivers/gpu/drm/i915/intel_dp.c
> > > > @@ -5108,9 +5108,6 @@ static void icl_update_tc_port_type(struct drm_i915_private *dev_priv,
> > > >  			      tc_type_name(intel_dig_port->tc_type));
> > > >  }
> > > >  
> > > > -static void icl_tc_phy_disconnect(struct drm_i915_private *dev_priv,
> > > > -				  struct intel_digital_port *dig_port);
> > > > -
> > > >  /*
> > > >   * This function implements the first part of the Connect Flow described by our
> > > >   * specification, Gen11 TypeC Programming chapter. The rest of the flow (reading
> > > > @@ -5145,6 +5142,7 @@ static bool icl_tc_phy_connect(struct drm_i915_private *dev_priv,
> > > >  	val = I915_READ(PORT_TX_DFLEXDPPMS);
> > > >  	if (!(val & DP_PHY_MODE_STATUS_COMPLETED(tc_port))) {
> > > >  		DRM_DEBUG_KMS("DP PHY for TC port %d not ready\n", tc_port);
> > > > +		WARN_ON(dig_port->tc_legacy_port);
> > > >  		return false;
> > > >  	}
> > > >  
> > > > @@ -5176,8 +5174,8 @@ static bool icl_tc_phy_connect(struct drm_i915_private *dev_priv,
> > > >   * See the comment at the connect function. This implements the Disconnect
> > > >   * Flow.
> > > >   */
> > > > -static void icl_tc_phy_disconnect(struct drm_i915_private *dev_priv,
> > > > -				  struct intel_digital_port *dig_port)
> > > > +void icl_tc_phy_disconnect(struct drm_i915_private *dev_priv,
> > > > +			   struct intel_digital_port *dig_port)
> > > >  {
> > > >  	enum tc_port tc_port = intel_port_to_tc(dev_priv, dig_port->base.port);
> > > >  
> > > > @@ -5222,7 +5220,8 @@ static bool icl_tc_port_connected(struct drm_i915_private *dev_priv,
> > > >  	bool is_legacy, is_typec, is_tbt;
> > > >  	u32 dpsp;
> > > >  
> > > > -	is_legacy = I915_READ(SDEISR) & SDE_TC_HOTPLUG_ICP(tc_port);
> > > > +	is_legacy = intel_dig_port->tc_legacy_port ||
> > > > +		I915_READ(SDEISR) & SDE_TC_HOTPLUG_ICP(tc_port);
> > > >  
> > > >  	/*
> > > >  	 * The spec says we shouldn't be using the ISR bits for detecting
> > > > @@ -5233,7 +5232,14 @@ static bool icl_tc_port_connected(struct drm_i915_private *dev_priv,
> > > >  	is_tbt = dpsp & TC_LIVE_STATE_TBT(tc_port);
> > > >  
> > > >  	if (!is_legacy && !is_typec && !is_tbt) {
> > > > -		icl_tc_phy_disconnect(dev_priv, intel_dig_port);
> > > > +		/*
> > > > +		 * We disconnect from legacy mode only during system
> > > > +		 * suspend and driver unloading, otherwise we keep the port in
> > > > +		 * legacy mode even after an HPD disconnect event.
> > > > +		 */
> > > > +		if (intel_dig_port->tc_type != TC_PORT_LEGACY)
> > > > +			icl_tc_phy_disconnect(dev_priv, intel_dig_port);
> > > > +
> > > >  		return false;
> > > >  	}
> > > >  
> > > > @@ -5542,7 +5548,7 @@ intel_dp_connector_unregister(struct drm_connector *connector)
> > > >  	intel_connector_unregister(connector);
> > > >  }
> > > >  
> > > > -void intel_dp_encoder_destroy(struct drm_encoder *encoder)
> > > > +void intel_dp_encoder_flush_work(struct drm_encoder *encoder)
> > > >  {
> > > >  	struct intel_digital_port *intel_dig_port = enc_to_dig_port(encoder);
> > > >  	struct intel_dp *intel_dp = &intel_dig_port->dp;
> > > > @@ -5565,9 +5571,14 @@ void intel_dp_encoder_destroy(struct drm_encoder *encoder)
> > > >  	}
> > > >  
> > > >  	intel_dp_aux_fini(intel_dp);
> > > > +}
> > > > +
> > > > +static void intel_dp_encoder_destroy(struct drm_encoder *encoder)
> > > > +{
> > > > +	intel_dp_encoder_flush_work(encoder);
> > > >  
> > > >  	drm_encoder_cleanup(encoder);
> > > > -	kfree(intel_dig_port);
> > > > +	kfree(enc_to_dig_port(encoder));
> > > >  }
> > > >  
> > > >  void intel_dp_encoder_suspend(struct intel_encoder *intel_encoder)
> > > > diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> > > > index d08f08f607dd..97c422bea7fb 100644
> > > > --- a/drivers/gpu/drm/i915/intel_drv.h
> > > > +++ b/drivers/gpu/drm/i915/intel_drv.h
> > > > @@ -1234,6 +1234,7 @@ struct intel_digital_port {
> > > >  	/* Used for DP and ICL+ TypeC/DP and TypeC/HDMI ports. */
> > > >  	enum aux_ch aux_ch;
> > > >  	enum intel_display_power_domain ddi_io_power_domain;
> > > > +	bool tc_legacy_port:1;
> > > >  	enum tc_port_type tc_type;
> > > >  
> > > >  	void (*write_infoframe)(struct intel_encoder *encoder,
> > > > @@ -1806,7 +1807,7 @@ void intel_dp_sink_set_decompression_state(struct intel_dp *intel_dp,
> > > >  					   bool enable);
> > > >  void intel_dp_encoder_reset(struct drm_encoder *encoder);
> > > >  void intel_dp_encoder_suspend(struct intel_encoder *intel_encoder);
> > > > -void intel_dp_encoder_destroy(struct drm_encoder *encoder);
> > > > +void intel_dp_encoder_flush_work(struct drm_encoder *encoder);
> > > >  bool intel_dp_compute_config(struct intel_encoder *encoder,
> > > >  			     struct intel_crtc_state *pipe_config,
> > > >  			     struct drm_connector_state *conn_state);
> > > > @@ -1874,6 +1875,8 @@ bool intel_dp_read_dpcd(struct intel_dp *intel_dp);
> > > >  int intel_dp_link_required(int pixel_clock, int bpp);
> > > >  int intel_dp_max_data_rate(int max_link_clock, int max_lanes);
> > > >  bool intel_digital_port_connected(struct intel_encoder *encoder);
> > > > +void icl_tc_phy_disconnect(struct drm_i915_private *dev_priv,
> > > > +			   struct intel_digital_port *dig_port);
> > > >  
> > > >  /* intel_dp_aux_backlight.c */
> > > >  int intel_dp_aux_init_backlight_funcs(struct intel_connector *intel_connector);
> > > > -- 
> > > > 2.13.2
> > > > 
> > > > _______________________________________________
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