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

Lewis Toohey
2014-05-25T20:43:21Z

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.

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$