[Intel-gfx] [PATCH] properly enable the blc controller on the right pipe

[Carsten Emde]

On 06/11/2012 10:51 AM, Daniel Vetter wrote:
> On Sun, Jun 3, 2012 at 1:08 AM, Daniel Vetter<daniel at ffwll.ch>  wrote:
>> On Fri, Apr 27, 2012 at 10:18:08PM +0200, Carsten Emde wrote:
>>>>>> Depending upon how things are set up, this might help.
>>>>> Yeah, thanks a lot, works great now!
>>>>> I removed patch 3/4 and 4/4 and pushed this one; so currently applied are:
>>>>> [PATCH 1/4] drm/i915: clear up backlight inversion confusion on gen4
>>>>> [PATCH 2/4] drm/i915: completely revert the invert brightness quirk
>>>>> [PATCH] properly enable the blc controller on the right pipe
>>>> Hey, that was just a quick hack to check things ;-)
>>> Sorry, too many things in parallel.
>>>
>>> Spent some time reading the docs you mentioned - will continue to
>>> work on the backlight brightness problem and prepare another patch.
>>> I just need some more time.
>>
>> Ok, I've stitched together some real patches and actually tested them.
>> While doing so I've noticed that the patch you've tested essentially
>> disables the i915 backlight control and leaves everything to the legacy or
>> platform backlight control.
>>
>> New patches are at
>>
>> http://cgit.freedesktop.org/~danvet/drm/log/?h=backlight-confusion
>>
>> Note that these do not include the revert for the backlight inversion
>> quirk. You either have to revert that yourself for testing or disable the
>> backlight inversion on the kernel bootline.
>>
>> Testing feedback highly welcome.
>
> I've updated my backlight-confusion branch with new patches for gen4
> (it doesn't seem to work for these machines yet). Can you please test
> the updated branch?
I have added an additional test rack (#6) to our QA farm (osadl.org/QA) 
and populated this rack solely with notebooks that are equipped with 
Intel graphics board:

Slot #1: Lenovo T61/7661W4G, Intel GMA X3100
Slot #2: IBM T601951-A47, Intel GMA 950
Slot #4: Acer Homa/Extensa 5230E-901G16N, Intel GMA 4500MHD
Slot #5: Acer Morar/TravelMate 2410, Intel GMA 900
Slot #6: Dell Inspirion 1300/0RJ272, Intel GMA 900
Slot #7: Acer Aspire 5734Z, Intel GMA 4500M

With the exception of slot #4 that runs a 3.2-based kernel, all other 
notebooks run a 3.4-based kernel. The notebook in Slot #7 is the one 
with the backlight headache. Unfortunately :-; no other notebook had any 
backlight problem when running a vanilla kernel, even the two new Acers 
are behaving well.

In the meantime, however, I have received a report that the Acer 5732Z 
has the same problem. I am sure that the reporter will be willing to 
help with testing. Looks like the backlight problem is very specific to 
Acer Aspire 573xZ. But I agree that a generic solution always is better 
than a quirk.

I've checked out the backlight-confusion branch of your git tree and 
tested it with and without the Acer quirk. I can report that the 
backlight works correctly with either version. I will now contact the 
owner of the Acer Aspire 5732Z and ask him to test the 
backlight-confusion branch without the Acer quirk on his notebook as well.

Do you wish me to do any other test?

	-Carsten.