Re: Bug Report - [Acer Aspire V5-122P] Unable to adjust screen brightness

Aaron Lu
2014-06-03T01:22:36Z

On 05/30/2014 09:12 PM, Lewis Toohey wrote:
> Aaron
>
> I am in the process of performing this bisection, however, I need a
> bit of advice.
>
> I have got a mix of results following suspend right through from (i)
> system reboot; (ii) "low graphics mode" error; (iii) restore but
> sluggish performance; and (iv) restore but *very* sluggish
> performance.

Is the sluggish performance experienced with a GUI environment?

>
> What should qualify as a bad commit? Anything other than a "perfect" restore?

I think ii/iii/iv all qualify as bad, if there is no such problem
in previous kernels. And yes, a perfect restore is expected, assume
the system is able to do a perfect restore with old kernels.

Thanks,
Aaron

>
> Many thanks
>
> On 27 May 2014 02:12, Aaron Lu <aaron.lu@intel.com> wrote:
>> On 05/27/2014 03:09 AM, Lewis Toohey wrote:
>>> On 26 May 2014 13:18, Lewis Toohey <lewis@toohey.co.uk> wrote:
>>>> On 26 May 2014 06:48, Aaron Lu <aaron.lu@intel.com> wrote:
>>>>> On 05/26/2014 04:42 AM, Lewis Toohey wrote:
>>>>>> On 23 May 2014 13:50, Hans de Goede <hdegoede@redhat.com> wrote:
>>>>>>> Hi Lewis et all,
>>>>>>>
>>>>>>> On 05/23/2014 02:07 PM, Lewis Toohey wrote:
>>>>>>>> On 23 May 2014 02:34, Aaron Lu <aaron.lu@intel.com> wrote:
>>>>>>>>> On 05/21/2014 09:02 PM, Lewis Toohey wrote:
>>>>>>>>>> Hi Aaron
>>>>>>>>>>
>>>>>>>>>> I followed your instructions and can report some limited success. I
>>>>>>>>>> have two interfaces listed in /sys/class/backlight namely:
>>>>>>>>>> acpi_video0 radeon_bl0
>>>>>>>>>>
>>>>>>>>>> max_brightness for acpi_video0 is 11. Echo-ing new values to
>>>>>>>>>> brightness appears to have no effect.
>>>>>>>>>>
>>>>>>>>>> max_brightness for radeon_bl0 is 255. Echo-ing new values to
>>>>>>>>>> brightness does adjust the screen brightness as you would expect.
>>>>>>>>>>
>>>>>>>>>> Results are the same on both battery and powered.
>>>>>>>>>>
>>>>>>>>>> I hope that is useful.
>>>>>>>>>
>>>>>>>>> I think Hans' patchset should solve your problem, can you please give it
>>>>>>>>> a try? You will need to pass the video.use_native_backlight=1 to kernel
>>>>>>>>> cmdline when testing, thanks.
>>>>>>>>>
>>>>>>>>> [PATCH resend 0/4] Make video.use_native_backlight=1 work properly with nouveau
>>>>>>>>> http://www.spinics.net/lists/dri-devel/msg59941.html
>>>>>>>>>
>>>>>>>>> -Aaron
>>>>>>>>
>>>>>>>> Aaron
>>>>>>>>
>>>>>>>> Thank you for this. Unfortunately I am going to have to ask you for a
>>>>>>>> bit of help here as I am now, officially, "out of my depth". I
>>>>>>>> appreciate this is a pain as you will have to take time explaining it
>>>>>>>> to me and I apologise for that.
>>>>>>>>
>>>>>>>> I have figured out how to pass the kernel command line argument, this
>>>>>>>> is not an issue.
>>>>>>>>
>>>>>>>> I have located the patch you refer to here:
>>>>>>>> https://bugzilla.redhat.com/attachment.cgi?id=894577
>>>>>>>> (which I believe is correct) but I cannot figure out how to apply it.
>>>>>>>
>>>>>>> That is not the right patch, you need a set of 2 patches. I've attached
>>>>>>> them to this mail. Note please ignore the numbering starting at 6, these
>>>>>>> are the 2 patches you need. You will need to build a Linux kernel with
>>>>>>> these 2 patches applied, see your distributions documentation on how
>>>>>>> to build a kernel from source.
>>>>>>>
>>>>>>> I don't know which distro you are using, I've a Fedora kernel with this
>>>>>>> patches included available here:
>>>>>>>
>>>>>>> http://people.fedoraproject.org/~jwrdegoede/rhbz1093171/
>>>>>>>
>>>>>>> Regards,
>>>>>>>
>>>>>>> Hans
>>>>>>
>>>>>> Hans
>>>>>>
>>>>>> Unfortunately I am unable to apply these patches against the latest
>>>>>> mainline kernel. I get two fails when applying the second patch file
>>>>>> and then the kernel will not compile. Please see output information
>>>>>> below.
>>>>>
>>>>> I've prepared a git branch for you:
>>>>> https://github.com/aaronlu/linux.git for-lewis
>>>>>
>>>>> It's based on Rafael's linux-next plus Hans' patch 2 and 3.
>>>>>
>>>>> Thanks,
>>>>> Aaron
>>>>>
>>>>>>
>>>>>> Can you advise?
>>>>>>
>>>>>> Many thanks
>>>>>>
>>>>>> ===APPLYING PATCHES TO LATEST MAINLINE KERNEL====
>>>>>>
>>>>>> lewis@HappyFunMeaowMeaow:~/KernelTesting/Kernel/linux$ patch -p1 <
>>>>>> 0006-backlight-Add-backlight-device-un-registration-notif.patch
>>>>>> (Stripping trailing CRs from patch; use --binary to disable.)
>>>>>> patching file drivers/video/backlight/backlight.c
>>>>>> (Stripping trailing CRs from patch; use --binary to disable.)
>>>>>> patching file include/linux/backlight.h
>>>>>> lewis@HappyFunMeaowMeaow:~/KernelTesting/Kernel/linux$ patch -p1 <
>>>>>> 0007-acpi-video-Unregister-the-backlight-device-if-a-raw-.patch
>>>>>> (Stripping trailing CRs from patch; use --binary to disable.)
>>>>>> patching file drivers/acpi/video.c
>>>>>> Hunk #1 FAILED at 151.
>>>>>> Hunk #2 succeeded at 161 (offset -1 lines).
>>>>>> Hunk #3 FAILED at 1837.
>>>>>> Hunk #4 succeeded at 1868 (offset -113 lines).
>>>>>> Hunk #5 succeeded at 1999 (offset -113 lines).
>>>>>> Hunk #6 succeeded at 2023 (offset -113 lines).
>>>>>> 2 out of 6 hunks FAILED -- saving rejects to file drivers/acpi/video.c.rej
>>>>>>
>>>>>>
>>>>>> ==LAST LINES OF BUILD BEFORE FAIL===
>>>>>>
>>>>>> CC [M] fs/xfs/xfs_ioctl32.o
>>>>>> LD [M] fs/xfs/xfs.o
>>>>>> make[1]: Leaving directory `/home/lewis/KernelTesting/Kernel/linux'
>>>>>> make: *** [debian/stamp/build/kernel] Error 2
>>>>>> lewis@HappyFunMeaowMeaow:~/KernelTesting/Kernel/linux$
>>>>>>
>>>>>>
>>>>>
>>>>
>>>> Aaron
>>>>
>>>> Many thanks for this. I can confirm that booting with this kernel and
>>>> passing the video.use_native_backlight = 1 argument means that the
>>>> backlight works perfectly on my laptop (both using the keyboard hot
>>>> keys and the gnome/unity settings applet).
>>>>
>>>> I'll post to the ubuntu launchpad page later with instructions for
>>>> other people to do this. I assume its presence in the linux-next tree
>>>> means that it will be fixed in an upcoming kernel release? (sorry, I
>>>> don't know quite how the process works).
>>>>
>>>> If I can provide more information or do some more useful testing
>>>> please do not hesitate to let me know.
>>>>
>>>> Thank you both for your help - really appreciated.
>>>>
>>>> --
>>>> Lewis
>>>>
>>>
>>> Aaron
>>>
>>> Just one final point in case it is relevant / useful - although it
>>> fixes the backlight issue this kernel version breaks the suspend
>>> resume functionality for me (the system will suspend but cannot come
>>> back from it).
>>
>> That sounds like a regression somewhere and a git bisect would be great
>> if that's possible for you.
>>
>> Thanks,
>> Aaron
>>
>>>
>>> Not asking for a fix (appreciate it is a testing base), just thought
>>> it might be useful to know.
>>>
>>> Thanks again
>>>
>>>
>>
>
>
>