On 26 May 2014 06:48, Aaron Lu <aaron.lu@xxxxxxxxx> wrote: > On 05/26/2014 04:42 AM, Lewis Toohey wrote: >> On 23 May 2014 13:50, Hans de Goede <hdegoede@xxxxxxxxxx> 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@xxxxxxxxx> 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 Lewis@xxxxxxxxxxxx 0782 588 4158 -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
