Re: [PATCH 00/13] drm/i915: backlight rewrite

[Imre Deak <imre.deak@intel.com>]

On Fri, 2013-11-08 at 16:48 +0200, Jani Nikula wrote:
> Hi all -
> 
> This series is a successor to [1], but with too many changes to list so
> I'll just consider this v1 of the patches.
> 
> This is pretty much a rewrite of our backlight code. Highlights:
> 
> * All the platform specific stuff in platform specific functions. The
>   code is much easier to follow, and it will be easier to enable future
>   platforms without breaking old ones all the time.
> 
> * Backlight enable writes all the backlight registers based on
>   information retrieved at setup stage. We no longer depend on what's in
>   the registers prior to enable, which should make things more
>   deterministic, and we no longer need to save/restore backlight
>   registers.
> 
> * We no longer keep reading max backlight value or combination mode bits
>   etc. from the registers all over the place. All that is based on the
>   initial values read in the setup stage.
> 
> TODO:
> 
> * If initial setup in registers is bogus, we should try to read the
>   values from VBT and/or try to use sane defaults. (This problem we have
>   already, not introduced by the series.)
> 
> I've tested this so far on ILK and IVB, trying carefully keep it working
> commit by commit to keep things bisectable. More testing across
> platforms is very much needed. We have a history with backlight...
> 
> Also available at backlight-rework branch at [2].

Looks like a nice improvement to code readability and separation of init
vs. run-time HW programming steps. The diff is big and I only managed to
review patches 1-9 so far; afaics those could be applied even
separately. r-bs and some nitpicks inlined.

--Imre