[Intel-gfx] [PATCH] drm/i915/gen9+: Rely on VBT DDI port info for eDP detection

[Imre Deak]

On Wed, 2016-12-21 at 10:34 +0200, Jani Nikula wrote:
> On Tue, 20 Dec 2016, Imre Deak <imre.deak at intel.com> wrote:
> > On ti, 2016-12-20 at 18:02 +0200, David Weinehall wrote:
> > > On Tue, Dec 20, 2016 at 05:12:49PM +0200, Imre Deak wrote:
> > > > There is at least one APL based system using port A in DP mode
> > > > (connecting to an on-board DP->VGA adaptor). Atm we'll configure port A
> > > > unconditionally as eDP which is incorrect in this case. Fix this by
> > > > relying on the VBT DDI port 'internal port' flag instead on all ports
> > > > GEN9 onwards. For now chicken out from doing this on earlier DDI
> > > > platforms too.
> > > > 
> > > > Signed-off-by: Imre Deak <imre.deak at intel.com>
> > > > ---
> > > >  drivers/gpu/drm/i915/i915_drv.h   | 1 +
> > > >  drivers/gpu/drm/i915/intel_bios.c | 1 +
> > > >  drivers/gpu/drm/i915/intel_dp.c   | 3 +++
> > > >  3 files changed, 5 insertions(+)
> > > > 
> > > > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> > > > index 7e94e506..42fb7e9 100644
> > > > --- a/drivers/gpu/drm/i915/i915_drv.h
> > > > +++ b/drivers/gpu/drm/i915/i915_drv.h
> > > > @@ -1669,6 +1669,7 @@ struct ddi_vbt_port_info {
> > > >  	uint8_t supports_dvi:1;
> > > >  	uint8_t supports_hdmi:1;
> > > >  	uint8_t supports_dp:1;
> > > > +	uint8_t supports_edp:1;
> > > >  
> > > >  	uint8_t alternate_aux_channel;
> > > >  	uint8_t alternate_ddc_pin;
> > > > diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
> > > > index 1cf2fa6..60fdd31 100644
> > > > --- a/drivers/gpu/drm/i915/intel_bios.c
> > > > +++ b/drivers/gpu/drm/i915/intel_bios.c
> > > > @@ -1161,6 +1161,7 @@ static void parse_ddi_port(struct drm_i915_private *dev_priv, enum port port,
> > > >  	info->supports_dvi = is_dvi;
> > > >  	info->supports_hdmi = is_hdmi;
> > > >  	info->supports_dp = is_dp;
> > > > +	info->supports_edp = is_edp;
> > > >  
> > > >  	DRM_DEBUG_KMS("Port %c VBT info: DP:%d HDMI:%d DVI:%d EDP:%d CRT:%d\n",
> > > >  		      port_name(port), is_dp, is_hdmi, is_dvi, is_edp, is_crt);
> > > > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> > > > index d37cb00..7f3f4fa 100644
> > > > --- a/drivers/gpu/drm/i915/intel_dp.c
> > > > +++ b/drivers/gpu/drm/i915/intel_dp.c
> > > > @@ -4983,6 +4983,9 @@ bool intel_dp_is_edp(struct drm_i915_private *dev_priv, enum port port)
> > > >  	if (INTEL_GEN(dev_priv) < 5)
> > > >  		return false;
> > > >  
> > > > +	if (INTEL_GEN(dev_priv) >= 9)
> > > > +		return dev_priv->vbt.ddi_port_info[port].supports_edp;
> > > > +
> > > 
> > > We already have intel_bios_is_port_edp() that tries to
> > > discern whether the port is eDP or not.
> > > 
> > > Wouldn't that function be usable for this purpose?
> > > 
> > > If so, doing:
> > > 
> > > if (port == PORT_A && INTEL_GEN(dev_priv) < 9)
> > > 	return true;
> > > 
> > > return intel_bios_is_port_edp(dev_priv, port);
> > > 
> > > should be enough. If not, maybe it should be fixed instead of
> > > introducing a new way of doing things.
> > 
> > intel_bios_is_port_edp() does on old platforms what parse_ddi_port()
> > for DDI platforms. I find it clearer to have all the platform checks in
> > one place in intel_dp_is_edp() to decide which info to use.
> > 
> > We could move the parsing in intel_bios_is_port_edp() to happen during
> > the early VBT parsing on old platforms and use the DDI port info for
> > those too not sure if it's feasible or if it's worth the effort.
> 
> IMO everything that looks at VBT for the info should be abstracted into
> intel_bios_is_port_edp(). I don't like to spread out things like, if
> this then look at VBT here, else look at VBT there, or something else.

Ok, I can move the DDI port lookup there. I'll also use that info for all
DDI platforms, keeping the fixed port A->eDP mapping on GEN<9 for now.

--Imre