[PATCH] drm: Add downclock quirk for Samsung LTN121AT10-301

[Rafał Miłecki]

2012/5/30 Sean Paul <seanpaul at chromium.org>:
> On Tue, May 29, 2012 at 5:23 PM, Alex Deucher <alexdeucher at gmail.com> wrote:
>> On Tue, May 29, 2012 at 4:33 PM, Sean Paul <seanpaul at chromium.org> wrote:
>>> On Tue, May 29, 2012 at 10:43 AM, Alex Deucher <alexdeucher at gmail.com> wrote:
>>>> On Mon, May 28, 2012 at 1:20 PM, Sean Paul <seanpaul at chromium.org> wrote:
>>>>> On Wed, Jan 18, 2012 at 10:06 AM, Sean Paul <seanpaul at chromium.org> wrote:
>>>>>> Add a quirk which adds a new downclocked mode to the EDID of Samsung
>>>>>> LTN121AT10-301 panels. This allows the intel driver to apply downclocking
>>>>>> and save power.
>>>>>>
>>>>>
>>>>> Is there any feedback on the patch? I'd like to get it merged if possible.
>>>>
>>>> This seems like something that should be specific to the intel driver
>>>> rather than risking problems with this monitor on other drivers.
>>>>
>>>
>>> Thanks for the feedback, Alex. I had originally put this in the intel
>>> driver, but moved it since it was a nasty hack. Furthermore, it was
>>> less obvious that the mode was available, since it was hidden to all
>>> layers above i915. The panel is just fine with the lower refresh rate,
>>> so it shouldn't have any issues with other drivers.
>>
>> Well it doesn't really seem like a quirk per se, the monitor works
>> just fine without it.  You are basically just adding an arbitrary new
>> user defined mode that happens to work on the monitor.  Seems like you
>> should just be adding the mode with xrandr or equivalent.
>>
>
> Unfortunately, adding it via xrandr won't take advantage of the i915
> lvds downclocking feature, which is the motivation for the patch.
>
> At any rate, it doesn't look like there's any interest in picking this
> patch up, so we'll just carry it locally in chromium-os :(

May I ask why? AFAIU you're just copying PREFERRED mode and changing
it's clock. xrandr allows you to set custom clock, doesn't it?

-- 
Rafał