[Intel-gfx] [PATCH 3/3] drm/i915/display: remove strap checks from gen 9

[Ville Syrjälä]

On Tue, Apr 13, 2021 at 10:22:24AM -0700, Lucas De Marchi wrote:
> On Tue, Apr 13, 2021 at 06:45:16PM +0300, Ville Syrjälä wrote:
> >On Mon, Apr 12, 2021 at 11:09:27PM -0700, Lucas De Marchi wrote:
> >> Direction on gen9+ was to stop reading the straps and only rely on the
> >> VBT for marking the port presence. This happened while dealing with
> >> WaIgnoreDDIAStrap and instead of using it as a WA, it should now be the
> >> normal flow. See commit 885d3e5b6f08 ("drm/i915/display: fix comment on
> >> skl straps").
> >>
> >> For gen 10 it's hard to say if this will work or not since I can't test
> >> it, so leave it with the same behavior as before.
> >>
> >> For PCH_TGP we should still rely on the VBT to make ports E and F not
> >> available.
> >>
> >> Signed-off-by: Lucas De Marchi <lucas.demarchi at intel.com>
> >> Reviewed-by: Anusha Srivatsa <anusha.srivatsa at intel.com>
> >> ---
> >>  drivers/gpu/drm/i915/display/intel_display.c | 36 ++++++--------------
> >>  1 file changed, 11 insertions(+), 25 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> >> index d62ce9c87748..5a03cbba0280 100644
> >> --- a/drivers/gpu/drm/i915/display/intel_display.c
> >> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> >> @@ -10883,34 +10883,25 @@ static void intel_setup_outputs(struct drm_i915_private *dev_priv)
> >>  		intel_ddi_init(dev_priv, PORT_B);
> >>  		intel_ddi_init(dev_priv, PORT_C);
> >>  		vlv_dsi_init(dev_priv);
> >> +	} else if (DISPLAY_VER(dev_priv) == 9) {
> >
> >Should be >=10 I presume? Or did we want ot handle cnl along with
> 
> why >= 10? The only DISPLAY_VER() == 10 platforms out there are handled
> in the branch above. I can make it >= 9, but not >= 10. Intention was to
> handle skl/kbl here.

Yeah, meant to write >=9. Cnl not really a thing, but I would get
confused if we started skipping it in some places while still
handling it in others. I guess we may want to consider just nuking
cnl totally everywhere, but until that time I think we should keep
things consistent.

> 
> 
> >icl perhaps? Doesn't really matter I suppose, but it's surely
> >going to consfuse the me the next time I read this.
> >
> >> +		intel_ddi_init(dev_priv, PORT_A);
> >> +		intel_ddi_init(dev_priv, PORT_B);
> >> +		intel_ddi_init(dev_priv, PORT_C);
> >> +		intel_ddi_init(dev_priv, PORT_D);
> >> +		intel_ddi_init(dev_priv, PORT_E);
> >> +		intel_ddi_init(dev_priv, PORT_F);
> >
> >DDI F isn't a thing on skl/derivatives, so I'd probably skip it on
> >those. Could just use IS_CNL_WITH_PORT_F() to match the looks of
> >the icl stuff.
> 
> I was actually looking at ICL and thinking "shouldn't this hack for
> broken VBT be hidden in intel_bios.c?"  I think we should trust what we
> parse from VBT everywhere  except of course in intel_bios.c where we
> fixup when the VBT is wrong. Thoughts?

I guess we could stuff it all in there somehow. Not sure.
Maybe Jani has thoughts on this?

-- 
Ville Syrjälä
Intel