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

[Imre Deak]

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.

--Imre

> 
> >  	if (port == PORT_A)
> >  		return true;
> 
> 
> Kind regards, David