ROSA Linux Bugzilla – Bug 5794
Add backlight control support for N150 and more
Last modified: 2015-11-23 17:35:38 MSK
This here work for me, can somebody create a packages, which copy that text file into that path, which get installed, when the Installer detect such a device ?
It seems to count for other Samsung Notebooks as well, does it hurt, if it get installed on each Samsung Laptop by default ?
First of all, before creating any packages, please do the following:
1. Check if booting with acpi_backlight=vendor kernel option helps.
2. It is worth looking at "Reporting Backlight Bugs" section in https://wiki.ubuntu.com/Kernel/Debugging/Backlight and checking what kind of backlight issue is yours.
3. Upload the data to us with hw-probe as usual. Twice:
* when the system booted without acpi_backlight=vendor
* when the system booted with acpi_backlight=vendor
Many backlight problems can be solved without additional packages.
By the way, different Samsung laptops may have different backlight interfaces, so it *may* hurt if a single solution is automatically applied during install.
I fix the issue on my netbook already, as stated.
(In reply to comment #2)
> I fix the issue on my netbook already, as stated.
Yes, I understand. However using that Xorg quirk for all Samsung laptops is error-prone.
If booting with 'acpi_backlight=vendor' helps, the problem can probably be fixed at the kernel level without the need for additional packages.
There is already a number of laptop-specific settings of this kind in the kernel. It should be possible to add another one for Samsung N150 and, perhaps, send it to the mainline kernel too.
That is why it is important to check if 'acpi_backlight=vendor' helps.
Sorry for my harsh style, was already sleepy. :)
I will try that, in order to improve the things a bit.
Detect just right now, that it is possible to enable the brightness control in BIOS, it was set to auto, which means controlled by the AC plug in / or not.
Is this place in the line "linux" correct ? http://funkyimg.com/view/YnR3
If yes: It doesnt work. Here is the hw-probe: http://hw.rosalinux.ru/index.php?probe=9acd2bc7dc
Can i do something else ?
SuperX support Backlight on this device out of the box.
(In reply to comment #6)
> SuperX support Backlight on this device out of the box.
Too little information, unfortunately.
If changing backlight works in another Linux distro, we need more info, as usual, to compare with. Namely:
1) the version of that Linux distro
2) system log (after changing brightness back and forth): the output of 'journalctl -ab' if the system is systemd-based; otherwise - kern.log, system.log, the output of dmesg, or whatever
3) the list of kernel parameters (cat /proc/cmdline)
4) ls -l /sys/class/backlight
5) whether they use that or a similar quirk (https://wiki.archlinux.org/index.php/Samsung_N150#Backlight) or not, and if they use it - the contents of that file in /etc/X11/xorg.conf.d/.
Created attachment 4198 [details]
The requested data, logs, etc.
It is better to attach the logs and other requested data here (easier to search, etc.) rather than to pastebin.
By the way, the screenshot you provided seems not to be for /etc/X11/xorg.conf.d/. Could you collect the output of 'ls -l /etc/X11/xorg.conf.d/' as root and post it here? Preferably, as plain text.
This here is the original folder in SuperX: http://funkyimg.com/view/ZAHv
I guess they use another name for the folder, which contains the data, that you mean, maybe this one here: http://funkyimg.com/view/ZAHw
superx@SuperX:~$ sudo ls -l /etc/X11/xorg.conf.d/
ls: cannot access /etc/X11/xorg.conf.d/: No such file or directory
PS: This screenshot in my previous comment result, since i copy the complete X11 folder from etc to my rosa installation, because i was without internet while i run this test, sitting in the park :)
That is, why this curious name in the path, if you mean that with
' the screenshot you provided seems not to be for /etc/X11/xorg.conf.d/ '
(In reply to comment #10)
> This here is the original folder in SuperX: http://funkyimg.com/view/ZAHv
Well, it looks like they do not store X11 configs in /etc/X11 at all. They should have the X11 log though, /var/log/Xorg*.log. If so, please attach it here, as text.
2 more things you can try on ROSA:
1. Check if things go better with the kernel 4.1.x and the firmware files updated from http://abf-downloads.rosalinux.ru/spectre_personal/container/2523362/i586/main/release/
Please check both with and without acpi_backlight=vendor.
As usual, please upload the data using hw-probe after you try.
2. If (1) does not help, you can blacklist 'samsung_laptop' kernel module, as root:
echo 'blacklist samsung_laptop' > /etc/modprobe.d/blacklist-samsung.conf
Then reboot, see what happens and, again, use hw-probe.
'samsung_laptop' is responsible for one of the backlight schemes on your laptop but it may be faulty. If you blacklist it, I suppose, the system should resort to intel_backlight, which is more reliable.
If nothing of the above helps, well, the only option would be to keep that Xorg quirk (/etc/X11/xorg.conf.d/20-intel.conf) on that particular laptop.
What is the downside of this quirk, please ?
Created attachment 4199 [details]
X.org log from SuperX
Is it important, to switch the backlight, before open this file ?
Yep, it seems to be solved. I set the BIOS Setting back to the default blocking option and there is no intel file anymore here in my /usr/share/X11/xorg.conf.d/ while the backlight control work still. 4.1.2 with casual updates.
Thanks a lot :D
Sorry, i install a new R6 on this device and the backlight is again disabled by default.
Still the only way to enable backlight control here: https://wiki.archlinux.org/index.php/Samsung_N150_#Backlight