[Intel-gfx] [PATCH v3 11/23] drm/i915: Handle the TCCOLD power-down event

[Imre Deak]

On Thu, Jun 27, 2019 at 01:12:51AM +0300, Souza, Jose wrote:
> On Wed, 2019-06-26 at 21:04 +0300, Imre Deak wrote:
> > Based on a recent BSpec update (Index/21750) we must handle the
> > TCCOLD
> > event associated with the DP-alt mode. We can detect this event by
> > reading an invalid all-1s value from FIA registers.
> > 
> > After detecting TCCOLD we will:
> > - fall back to TBT-alt mode when attempting to switch to DP-alt mode
> > - conclude that nothing is connected during live status detection
> > - WARN when already in unsafe mode, since then TCCOLD is unexpected
> > 
> > v2:
> > - Use DRM_DEBUG_KMS instead of DRM_DEBUG_DRIVER. (José)
> > v3:
> > - Use 0xffffffff instead of -1 as invalid FIA reg value.
> >   (José, Ville)
> > - Check for TCCOLD in icl_tc_phy_status_complete() too. (Ville)
> > 
> > Cc: José Roberto de Souza <jose.souza at intel.com>
> > Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> > Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > Signed-off-by: Imre Deak <imre.deak at intel.com>
> > ---
> >  drivers/gpu/drm/i915/display/intel_tc.c | 33 ++++++++++++++++++++++-
> > --
> >  1 file changed, 29 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/display/intel_tc.c
> > b/drivers/gpu/drm/i915/display/intel_tc.c
> > index 4243db6d25a7..96855250a5be 100644
> > --- a/drivers/gpu/drm/i915/display/intel_tc.c
> > +++ b/drivers/gpu/drm/i915/display/intel_tc.c
> > @@ -29,6 +29,8 @@ u32 intel_tc_port_get_lane_mask(struct
> > intel_digital_port *dig_port)
> >  
> >  	lane_mask = I915_READ(PORT_TX_DFLEXDPSP);
> >  
> > +	WARN_ON(lane_mask == 0xffffffff);
> 
> nit: Maybe define it?

Ok, makes sense, will add it (to this file only though, not under the
reg definition).

> 
> #define FIA_TCCOLD_VALUE 0xffffffff
> 
> Reviewed-by: José Roberto de Souza <jose.souza at intel.com>
> 
> 
> > +
> >  	return (lane_mask & DP_LANE_ASSIGNMENT_MASK(tc_port)) >>
> >  	       DP_LANE_ASSIGNMENT_SHIFT(tc_port);
> >  }
> > @@ -92,6 +94,12 @@ static u32 tc_port_live_status_mask(struct
> > intel_digital_port *dig_port)
> >  
> >  	val = I915_READ(PORT_TX_DFLEXDPSP);
> >  
> > +	if (val == 0xffffffff) {
> > +		DRM_DEBUG_KMS("Port %s: PHY in TCCOLD, nothing
> > connected\n",
> > +			      dig_port->tc_port_name);
> > +		return mask;
> > +	}
> > +
> >  	if (val & TC_LIVE_STATE_TBT(tc_port))
> >  		mask |= BIT(TC_PORT_TBT_ALT);
> >  	if (val & TC_LIVE_STATE_TC(tc_port))
> > @@ -111,12 +119,19 @@ static bool icl_tc_phy_status_complete(struct
> > intel_digital_port *dig_port)
> >  {
> >  	struct drm_i915_private *dev_priv = to_i915(dig_port-
> > >base.base.dev);
> >  	enum tc_port tc_port = intel_port_to_tc(dev_priv, dig_port-
> > >base.port);
> > +	u32 val;
> >  
> > -	return I915_READ(PORT_TX_DFLEXDPPMS) &
> > -	       DP_PHY_MODE_STATUS_COMPLETED(tc_port);
> > +	val = I915_READ(PORT_TX_DFLEXDPPMS);
> > +	if (val == 0xffffffff) {
> > +		DRM_DEBUG_KMS("Port %s: PHY in TCCOLD, assuming not
> > complete\n",
> > +			      dig_port->tc_port_name);
> > +		return false;
> > +	}
> > +
> > +	return val & DP_PHY_MODE_STATUS_COMPLETED(tc_port);
> >  }
> >  
> > -static void icl_tc_phy_set_safe_mode(struct intel_digital_port
> > *dig_port,
> > +static bool icl_tc_phy_set_safe_mode(struct intel_digital_port
> > *dig_port,
> >  				     bool enable)
> >  {
> >  	struct drm_i915_private *dev_priv = to_i915(dig_port-
> > >base.base.dev);
> > @@ -124,6 +139,13 @@ static void icl_tc_phy_set_safe_mode(struct
> > intel_digital_port *dig_port,
> >  	u32 val;
> >  
> >  	val = I915_READ(PORT_TX_DFLEXDPCSSS);
> > +	if (val == 0xffffffff) {
> > +		DRM_DEBUG_KMS("Port %s: PHY in TCCOLD, can't set safe-
> > mode to %s\n",
> > +			      dig_port->tc_port_name,
> > +			      enableddisabled(enable));
> > +
> > +		return false;
> > +	}
> >  
> >  	val &= ~DP_PHY_MODE_STATUS_NOT_SAFE(tc_port);
> >  	if (!enable)
> > @@ -134,6 +156,8 @@ static void icl_tc_phy_set_safe_mode(struct
> > intel_digital_port *dig_port,
> >  	if (enable && wait_for(!icl_tc_phy_status_complete(dig_port),
> > 10))
> >  		DRM_DEBUG_KMS("Port %s: PHY complete clear timed
> > out\n",
> >  			      dig_port->tc_port_name);
> > +
> > +	return true;
> >  }
> >  
> >  /*
> > @@ -172,7 +196,8 @@ static bool icl_tc_phy_connect(struct
> > intel_digital_port *dig_port)
> >  		return false;
> >  	}
> >  
> > -	icl_tc_phy_set_safe_mode(dig_port, false);
> > +	if (!icl_tc_phy_set_safe_mode(dig_port, false))
> > +		return false;
> >  
> >  	if (dig_port->tc_mode == TC_PORT_LEGACY)
> >  		return true;