[Intel-gfx] [PATCH 01/25] drm/i915: add new Haswell DIP controls registers

[Paulo Zanoni]

2012/5/9 Eugeni Dodonov <eugeni.dodonov at linux.intel.com>:
>
> Without this, I am getting a nice black screen though . But the latest
> theory is that perhaps we just need to send any infoframe for the hardware
> to catch up and work in HDMI mode?
>
I finally tested this :) I don't think anymore this is the case since
the ddi_func_ctl register seems correct.

Lots of theories:

- Without this patch, you just run cpt_write_infoframe, which can be
messing with a lot of registers that are not DIP registers on HSW
- With the patch, you set the control register to 0 at the HDMI init
time, which disables any DIP that might be sending bad data and
causing the black screen
- On my machine, with this patch, after booting and doing everything,
the dip control register is 0x00110000, which is totally not what we
set/want :)

-- 
Paulo Zanoni