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

Lewis Toohey
2014-05-30T13:12:55Z

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.

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

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