Bugzilla – Bug 368449
kernel, brightness fn-keys, laptop, notebook
Last modified: 2008-07-30 15:33:15 UTC
kernel(2.6.22.17-0.1-default) loads and breaks brightness fn-keys functionality and sets brightness to the lowest level on samsung R70 aura T7500 Denet notebook. brightness keys are fully hardware supported, no driver is needed. if laptop is not pluged in, during the kernel is loading it sets the brightness to the lowest level, so it is practically impossible to see what is displayed on the screen :-( ps: brightness can be changed in grub, but then it will be reseted by kernel(or what ever).
This isn't a blocker since 10.3 was shipped already.
> if laptop is not pluged in, during the kernel is loading Can you find out which driver is actually doing this. Danny can this be hal or something from userspace? That means if AC is plugged in, everything works fine? Please paste lsmod, so that we could guess which module could cause this. I expect if you unplug AC adapter later, the brightness will go down again?
@Thomas: if this happens while boot only powersaved should be running (until login to desktop). HAL don't do anything with brightness without someone which tells HAL to do so. To check if powersaved was the problem: call 'insserv -r powersaved' and reboot the machine. (readd powersaved with 'insserv powersaved')
@Jeff, okey, my bad. @Thomas > Can you find out which driver is actually doing this. That means if AC is plugged in, everything works fine? > if AC is plugged in at start time, it set the maximal possible brightness level, and at least you can see, what is going on on the screen, but u still can not change brightness (back light). > I expect if you unplug AC adapter later, the brightness will go down again? no, the back light does not changes.
Created attachment 203719 [details] lsmod
Not sure what is going on. There is no specific laptop ACPI driver loaded. Video driver (which couls/should do brightness switching is not used at that times yet). Maybe best is you install the latest 11.0 in a small partition (if you still have some free place). If this is still an 11.0 issue, the priortity of the bug increases and we even might get some help from Intel ACPI mainline people. If not, we already have a clue that it might got fixed between 2.6.22 and 2.6.25-rcX.
@Danny > To check if powersaved was the problem... tried that, did not win any new information (nothing changes). booting in Failsafe mode, solves the problem.
If you are in grub, hit ESC and enter the grub text menu. Hit 'e' for edit and exchange the param vga=xxx to vga=normal (You may want to do this when booted in /boot/grub/menu.lst, it then permanently removes the splash screen at boot time). Can you upload dmesg output pls, and give as a hint at which position of the boot messages the brightness switch happens. Also try to boot with boot parameter: 1 Then you will only boot into runlevel 1 and a lot services are not started yet, is the screen still bright? Can you also attach output of acpidump command (as text/plain), pls.
I could imagine it works with osi="!Windows 2006" But I expect we do not (yet) have the patch for this parameter. Evgeny, can you still pls provide requested info, then I can double check and eventually provide a kernel (might take some days) to test.
Created attachment 205287 [details] dmesg
last 4 lines in dmesg appear when the fn keys for to increasing and decreasing back light are pressed. @Thomas, is there any easy and fast to follow HOWTO for testing opensuse 11... without affecting the running system?
Created attachment 205293 [details] acpidump
@ Thomas >Also try to boot with boot parameter: 1 i have tried to switch to runlevel 1 with the command init 1, so fn-keys does not work. >give as a hint at which position of the boot messages the brightness switch >happens. it does happen from the beginning, direct after grub menu. >I could imagine it works with osi="!Windows 2006" this notebook originally comes with windows vista, and it probably uses the vista way for changing brightness, so i can imagine that too.
It looks like your machine's backlight can be controlled through ACPI brightness extensions which are driven through the "video" kernel driver. This one is known to be broken on 10.3. > @Thomas, is there any easy and fast to follow HOWTO for testing opensuse > 11... without affecting the running system? I expect there is no live DVD for 11.0 out yet? Maybe you have an external USB disk you can install on or just still a bit of free space on the disk? You could possibly resize a partition with 10.3? We should really go for 11.0, it's a waste of time for 10.3. If we really find easy things to backport, it can still go into 10.3.
i have tried openSUSE 11 live cd form here ftp://ftp.suse.com/pub/projects/FactoryLiveCDs/LiveCD-KDE-20080405.iso 668336 KB 05.04.2008 15:20:00 uname -r: 2.6.25-rc8-12-default there is still the same ussue.
Best you also have a look whether there is a more recent BIOS. While looking for a BIOS is always a good idea..., your BIOS supports the IGD Integrated Graphics Device for which there is no Linux driver yet, but Lenovos also have such a device and do not switch to a black screen on battery... (If you find a BIOS update then check this *after* upgrading): Do you have any battery saving options in your BIOS configuration? Could you try 11.0 booting with: osi="!Windows 2006" boot parameter, pls. Also for 11.0: If you are in grub, hit ESC and enter the grub text menu. Hit 'e' for edit and exchange the param vga=xxx to vga=normal Could you point me to the line when the screen turns black when booting in your dmesg of comment #10. If you boot with AC plugged in and remove it later, does the screen turn black?
Evgeny, Please attached the lspci output. thomas, there are two ACPI video buses in this laptop. GFX0 AND NVID. IMO, GFX0 is for integrated Intel graphics card. It's weird that IGD bios code is implemented in the BIOS but noone will invoke this piece of code, while usually GDCK/GLID/GHDS should be invoked in _Lxx. Plus, there is only one _BCM method available in this BIOS, and it's located under NVID.LCD, which means that no brightness control available for any ACPI video device under GFX0... This bug seems to be a duplicate of http://bugzilla.kernel.org/show_bug.cgi?id=9939 So, as thomas suggested, I think acpi_osi="!Windows 2006" may help on this issue. Evgeny, please give it a try.
Created attachment 208035 [details] lspci
This will stay unfixed for 10.3. Best try latest factory or wait for the next 11.1 release (which should have 2.6.27) kernel.