[Intel-gfx] [PATCH] drm/i915/ddi: set has_infoframe flag on DDI too v2

[Daniel Vetter]

Let's be good citizen and summarize the important points from the irc
chat between Jesse&me.

On Thu, Nov 20, 2014 at 8:54 PM, Jesse Barnes <jbarnes at virtuousgeek.org> wrote:
>> Hm I dind't look too closely apparently at this. You again rely upon sw
>> state here, just encoder->type this time around. Which means you can't
>> upcast the intel_hdmi struct, and you also can't really rely upon the
>> encoder->crtc link (that's all just about to get reconstructed). Imo the
>> code should have stayed in the TRANS_DDI_MODE_SELECT_HDMI case.
>
> Hm, we look at the encoder->type later and check for eDP, so I figured
> it must be valid at this point.  It's easy enough to move though if
> not...

eDP is special since it doesn't change its personality ever. That's
why we get away with it. And there's also not really any indication
whether a given port would be eDP in the hw since at least on big core
the panel power sequencer is global (and not per-pipe like on vlv/bsw)
so we just can't tell. Well we could poke at the dp aux stuff.

>> The later depency upon encoder->crtc is an issue for everything !g4x, but
>> on hsw there's the additional issue that you have to look at the cpu
>> transcoder and I guess that part blows up.
>
> I'll check out Paulo's trace; haven't looked yet.

Summary from our irc analysis is in the patch I've just submitted.
Hopefully that fixes Paulo's backtrace.

>> g4x infoframe readout is probably broken too because it doesn't check that
>> the port selected is the one actually queried for.
>
> Yeah that looks like a separate bug from the infoframe_enabled
> additions.
>
>>
>> Overall I think we need to:
>> - Inline the g4x readout into the hdmi get_config function and check the
>>   port.
>> - Inline the ibx/cpt readout code into the relevant get_pipe_config
>>   functions (well pch config) since that state is per-pipe. We should
>>   probably double-check the port, too.
>> - Same inline for vlv and hsw, with the addition that we need to make sure
>>   on hsw to not try to read this for the edp transcoder.
>
> I'll check, we may not need to inline since we should be able to get
> the port info easily enough.

Per our discussion encoder->crtc gets reconstructed properly so we
should be able to rely on that relationship. Might be good paranoid
practice to double-check the port mapping for ibx/vlv, but imo not
really required.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch