Bug 57151
| Summary: | Backlight controls do not work | ||
|---|---|---|---|
| Product: | Drivers | Reporter: | leoni.massimiliano1 |
| Component: | Video(DRI - Intel) | Assignee: | intel-gfx-bugs (intel-gfx-bugs) |
| Status: | RESOLVED DUPLICATE | ||
| Severity: | normal | CC: | aaron.lu, intel-gfx-bugs |
| Priority: | P1 | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Kernel Version: | >=3.8.5 | Subsystem: | |
| Regression: | No | Bisected commit-id: | |
| Attachments: | lspci -v output | ||
|
Description
leoni.massimiliano1
2013-04-26 22:27:04 UTC
There is no code change in acpi video driver from 3.8.4 to 3.8.5. The following commit from graphics driver looks suspicious: 0e7a2fe01333f72c1cec1cd4d5293a62c770fa4f, can you please revert that commit and test? Thanks. Ehm.... I'm sorry but I'm not sure how to do this :) Which repository should I clone? Is there a guide somewhere? I have an update! I found out that, with one of the "problematic" kernels - I'm on 3.8.10 right now -, if I do $ su $ echo 0 > /sys/class/backlight/intel_backlight/brightness it completely restores correct behavior, i.e. plasma widget and special keys work and brightness can be adjusted. The problem is still present on following boots. Oddly, if I do $ sudo echo 0 > /sys/class/backlight/intel_backlight/brightness it says bash: /sys/class/backlight/intel_backlight/brightness: access denied. A friend suggested this could be a kernel bug, and may be the key to the solution. Is this any helpful? Hi, Sorry for the late reply. Please follow the below steps: 1 clone linux stable git tree $ git clone http://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git 2 checkout 3.8 branch $ git checkout linux-3.8.y 3 set local tree to commit 5016d9ac0938789e7aaba86be3e6fbf24e7b7bee $ git reset --hard 5016d9ac0938789e7aaba86be3e6fbf24e7b7bee then build kernel and see if everything works OK 4 if yes, set local tree to commit 0e7a2fe01333f72c1cec1cd4d5293a62c770fa4f $ git reset --hard 0e7a2fe01333f72c1cec1cd4d5293a62c770fa4f then build kernel again and see if everything works OK. Thanks. Ok,.... I'm not very used to compiling the kernel, so I'm finding it somewhat difficult: when I try make menuconfig, it asks me a lot of questions I don't know how to answer :) I think you can use your installed kernel's config file. $ cd linux_git_tree_you_have_cloned $ cp /boot/config-3.8.4 .config $ make oldconfig Then build kernel. You are very kind helping me like this :) However, I have no /boot/config-3.8.4 file [I use GRUB2, I think]. Attach the following command output as root: # lspci -v > lspci.out Then I can provide the config file for you to use. Created attachment 100811 [details]
lspci -v output
Here it is :)
P.s. Can I compile the kernel on a different machine and then install the package on this one? I have a desktop which can compile faster and on a HDD [I have an SSD on this one]. Hi, I've built the kernel for you. No initrd is required, so your root= command line will need to use /dev/sda? instead of UUID=. URL here, since bugzilla doesn't allow upload a file more than 1000KB: https://www.dropbox.com/s/sgxikmdkzmhhjzp/vmlinuz-bad https://www.dropbox.com/s/u6e1qfoktenynlr/vmlinuz-good Ok, I did some testing and here's the result. I took each of the files you shared and copied them into /boot/vmlinuz-linux, then rebooted. With vmlinuz-good, backlight controls worked; with vmlinuz-bad, they didn't, so I guess you found the core of the problem! [Maybe unnecessary to tell, with both of them I had some issues like networkmanager and kmix not working, but I think this is because you compiled it away from my hardware] Did I do well? Is there anything else I can do? :) Thanks a lot for your support! Thanks for the test, I'll move this bug to drm/intel category and I think they know what happened. Hi DRM guys, Looks like the following commit: commit 0e7a2fe01333f72c1cec1cd4d5293a62c770fa4f Author: Daniel Vetter <daniel.vetter@ffwll.ch> Date: Fri Mar 22 15:44:46 2013 +0100 Revert "drm/i915: write backlight harder" breaks backlight functionality of leoni's system, please kindly take a look, thanks. Awesome, I love the way bugreporting works :) Thank you all for this! The original commit "drm/i915: write backlight harder" fixed the issue on Dell XPS 13, but unfortunately it regressed other machines and had to be reverted. *** This bug has been marked as a duplicate of bug 47941 *** |