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 / Aaron Just by way of an update, I am trying to test this but have run into another gap in my knowledge. Essentially I can compile the standard ubuntu kernel (3.13) but the patch breaks this (I assume because the patch was written for a more recent kernel version). I don't know how to compile upstream kernels for ubuntu and have asked for help here: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1315834/comments/21 I will let you know when I make some progress. Thank you again for your efforts here. Much 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
