Re: [PATCH] drm/i915/cnl: Add AUX-F support

[Rodrigo Vivi <rodrigo.vivi@intel.com>]

On Fri, Jan 26, 2018 at 09:27:41PM +0000, Pandiyan, Dhinakaran wrote:
> 
> On Fri, 2018-01-26 at 09:15 -0800, Rodrigo Vivi wrote:
> > On some Cannonlake SKUs we have a dedicated Aux for port F,
> > that is only the full split between port A and port E.
> > 
> > There is still no Aux E for Port E, as in previous platforms,
> > because port_E still means shared lanes with port A.
> > 
> > v2: Rebase.
> > v3: Add couple missed PORT_F cases on intel_dp.
> > v4: Rebase and fix commit message.
> > v5: Squash Imre's "drm/i915: Add missing AUX_F power well string"
> > v6: Rebase on top of display headers rework.
> > v7: s/IS_CANNONLAKE/IS_CNL_WITH_PORT_F (DK)
> > v8: Fix Aux bits for Port F (DK)
> > v9: Fix VBT definition of Port F (DK).
> > v10: Squash power well addition to this patch to avoid
> >      warns as pointed by DK.
> > v11: Clean up squashed commit message. (David)
> > 
> > Cc: David Weinehall <david.weinehall@linux.intel.com>
> > Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
> > Cc: Lucas De Marchi <lucas.demarchi@intel.com>
> > Cc: Imre Deak <imre.deak@intel.com>
> > Cc: Manasi Navare <manasi.d.navare@intel.com>
> > Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
> > Reviewed-by: David Weinehall <david.weinehall@linux.intel.com>
> > ---
> >  drivers/gpu/drm/i915/i915_drv.h         |  1 +
> >  drivers/gpu/drm/i915/i915_irq.c         |  6 ++++++
> >  drivers/gpu/drm/i915/i915_reg.h         |  9 +++++++++
> >  drivers/gpu/drm/i915/intel_display.h    |  1 +
> >  drivers/gpu/drm/i915/intel_dp.c         |  8 ++++++++
> >  drivers/gpu/drm/i915/intel_runtime_pm.c | 21 +++++++++++++++++++++
> >  6 files changed, 46 insertions(+)
> 
> <snip>
> 
> > @@ -1342,6 +1345,7 @@ static i915_reg_t g4x_aux_ctl_reg(struct drm_i915_private *dev_priv,
> >  	case PORT_B:
> >  	case PORT_C:
> >  	case PORT_D:
> > +	case PORT_F:
> >  		return DP_AUX_CH_CTL(port);
> >  	default:
> >  		MISSING_CASE(port);
> > @@ -1356,6 +1360,7 @@ static i915_reg_t g4x_aux_data_reg(struct drm_i915_private *dev_priv,
> >  	case PORT_B:
> >  	case PORT_C:
> >  	case PORT_D:
> > +	case PORT_F:
> >  		return DP_AUX_CH_DATA(port, index);
> 
> I pointed this out in the last review, but it must have got lost among
> other comments and code.
> Why are these hunks needed? skl_aux_data_reg and skl_aux_ctl_reg already
> have the necessary changes and the gfx_ variants won't get called for
> INTEL_GEN >= 9

I missed those, but you are right.
yet another v comming without this...

> 
> <snip>
> 
> > @@ -1855,6 +1857,9 @@ void intel_display_power_put(struct drm_i915_private *dev_priv,
> >  #define CNL_DISPLAY_AUX_D_POWER_DOMAINS (		\
> >  	BIT_ULL(POWER_DOMAIN_AUX_D) |			\
> >  	BIT_ULL(POWER_DOMAIN_INIT))
> > +#define CNL_DISPLAY_AUX_F_POWER_DOMAINS (		\
> > +	BIT_ULL(POWER_DOMAIN_AUX_F) |			\
> > +	BIT_ULL(POWER_DOMAIN_INIT))
> >  #define CNL_DISPLAY_DC_OFF_POWER_DOMAINS (		\
> >  	CNL_DISPLAY_POWERWELL_2_POWER_DOMAINS |		\
> >  	BIT_ULL(POWER_DOMAIN_GT_IRQ) |			\
> 
> 
> Why is BIT_ULL(POWER_DOMAIN_AUX_F) not included in
> CNL_DISPLAY_POWERWELL_2_POWER_DOMAINS, while POWER_DOMAIN_AUX_B,
> POWER_DOMAIN_AUX_C and POWER_DOMAIN_AUX_D are?
> 
> If I understand this correctly, power_get(AUX_B) would
> enable both AUX_B powerwell and powerwell 2. 
> 
> But, power_get(AUX_F) would just enable AUX_F.
> 
> I don't see anything in the spec justifies why AUX_F should be treated
> differently.

agree. Shouldn't be different.
I will fix.

> 
> 
> 
> > @@ -2405,6 +2410,12 @@ static struct i915_power_well cnl_power_wells[] = {
> >  		.ops = &hsw_power_well_ops,
> >  		.id = SKL_DISP_PW_DDI_D,
> >  	},
> > +	{
> > +		.name = "AUX F",
> > +		.domains = CNL_DISPLAY_AUX_F_POWER_DOMAINS,
> > +		.ops = &hsw_power_well_ops,
> > +		.id = CNL_DISP_PW_AUX_F,
> > +	},
> 
> I wonder if placing AUX_F after dc_off and power well 2 has any impact.
> Is there an expected order that the hardware requires us to power these
> wells? For e.g, is it okay to enable power well 2 before enabling
> AUX_F?

The other matters now. That's how we are removing from the list
for platforms without port_f... array_size - 1. (-2 on the next that adds ddi one)

> 
> 
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