Re: [PATCH 0/4] drm/i915/dp: native aux read return value fixes and cleanup

Jani Nikula
2014-01-30T15:06:14Z

On Thu, 30 Jan 2014, Daniel Vetter <daniel@ffwll.ch> wrote:
> On Thu, Jan 30, 2014 at 11:37:00AM +0200, Jani Nikula wrote:
>> Fix and cleanup the rather confused native aux read return values and
>> return value checks. Maybe we'll get them right from now on. Just maybe.
>>
>> Did not have a chance to test this, I'm afraid, but it's pretty
>> straightforward.
>
> How does this fit in with Thierry's dp aux helper improvements? I prefer
> if we start to converge on that sooner than later ...

For the i2c-over-aux conversion

commit 8a5e6aeb30ecaf8f11a99c0d008c8935cd6fba9f
Author: Paulo Zanoni <paulo.r.zanoni@intel.com>
Date: Wed Oct 30 19:50:26 2013 -0200

drm/i915: turn the eDP VDD on for any i2c transactions

will be a PITA, as we lose control of that level in the stack.

So we'd need to move the vdd enable/disable higher or lower. Per that
commit, higher was problematic. If we move it lower, we may need to add
refcounting to the vdd, but then we'll lose the warn for "eDP VDD
already requested on\n".

Ideas welcome.

Jani.

--
Jani Nikula, Intel Open Source Technology Center