Bug 668694

I'm having the same problem with Acer Aspire 3100/5100. This worked way back on 11.1

Hi guys, any way to get this marked as confirmed? Thanks!

*** Bug 668691 has been marked as a duplicate of this bug. ***

Can you please try setting it with xbacklight (a cli tool) and see if it works good? Also please check dmesg output for something suspicous or rather feel free to attach it after you tried setting it with the keys and xbacklight.

Btw this is propably no KDE bug but more in the Kernel layer, but let's narrow it down first.

In recent days I have been experimenting on the issue.

IN my case, xbacklight says "No outputs have backlight property" all the time. With both a working backlight and a non-working backlight.

And I noticed that in /sys/class/backlight/  the acer-wmi is not there.

A did not have at hand a suse livecd, so I used Kubuntu 10.04 and 10.10 for reference.

10.04: loaded acer-wmi in /sys/class/backlight/ but xbacklight reported the same, BUT I could slide the backlight slide on powerdevil and the Fn keys worked fine.

In 10.10, Things were like in 11.4 Mx, but doing a manual modprobe solved it. That's weird because the module is supposed to be autoloaded...

In 11.4 Mx AND current RC1, as in K10.10 modprobe acer-wmi solves it partially.

Function Keys work, but the KDE tools don't recognize it. Which means that the powerdevil brightness slide does not work and more importantly power-save mode, do not automatically decreased brightness when in battery.

Doing cat /sys/class/backlight/acer-wmi/actual_brightness you can see your current brightness. IN acer this is usually in the 0~15 range.

The /proc facilities used to change baclight properties seem to have changed drastically since kernel 2.6.32 in /proc/acpi which used to feature a video directory where thing were tunable which is missing since at least kernel 2.6.35, and possibly long before.

In /sys/class/backlight/acer-wmi, nothing seems to be user tunable. It just show the info.

At least the Fn+key works this way, but that would not be good enough for non-techies and annoying for techies anyway.

There is something broken between the kernel and the user space utilities. The kernel should autoloader acer-wmi as per the documentation, KDE should be able to control the backlight if it is available like the Functions keys indicate, and xbacklight should provide better info and recognize the backlight when it is available after modprobing the acer-wmi module.

OK. I hope this experience can be helpful to others with Acer laptops and to devs to solved this issues.

This looks foremost like a kernel issue to me, especially as it doesn't load the module, I'll assign to kernel for now and see what they come up with.

Regarding the powerdevil issue it seems the acer laptops are flaky =/

could you please try this after loading acer-wmi?
http://dirk.net/2009/08/09/adjust-screen-brightness-in-ubuntu-via-xrandr/

powerdevil uses randr for brightness control (at least that what I read out of the source), so let's try poking around that first, as brightness control should work the same over all laptops and does work on mine I don't think it's powerdevils fault but some lower level

xrandr Does not work neither on 11.4 Mx nor Kubuntu 10.04.

xrandr --prop does not detect  the backlight, since it seems to rely on Xorg info. The xrandr man page defers in preference to the the xbacklight utility.

since the property is not listed with --prop, it fails when called with a "bad name" error.

I checked in Kubuntu 10.04, And xrandr equally does not detect the backlight, as well as xbacklight. But KDE and the overall system works just fine with the backlight.

In my experience Acer laptos are usually of better or equal quality that HP, Dell, etc. And from those most hardware issues I found were with HP, Dell, etc than with Acer. Opensuse in particular broke things with the forceful introduction of radeonhd which conflicted with older radeon-ati driver on ati cards giving a "not supported" status to opensuse since 11.2. WHile successfully operating through *buntu 9.10 to 10.04 as far as I can remember. I usually used opensuse on laptops until 11.2 broke things with ati on-board cards. So the "flaky" comment feels out of place in my opinion and personal experience.

Urghs, I didn't meant acer laptops in general but the brightness control, as there seem to be different issues when I tried googling for it. Also this wasn't meant to judge any overall quality or badmouthing acer systems, i am sorry for my poor choice of words.
And radeonhd, well I can only agree with you, this was shipped half baked, opensuse 11.3 uses the regular radeon driver again though.


Does xrandr --prop not even detect the backlight after forcefully loading the acer-wmi kernel module? Is there any negative output in dmesg after loading the module? Do you happen to have an old livecd around where it worked and try there as well?



There is a kde bugreport about failing backlight support, but there is also multiple things flying through, like hal having a better backlight support or solid should use more ways to set the backlight besides randr
https://bugs.kde.org/show_bug.cgi?id=257948

Right now I'm returning the 4810 that a less technical friend handed to test.

That leaves my personal aspire 3100 (with manually upgraded cpu and ram) as the only test platform for the time being.

SO I don't know if opening a new bug entry is appropiate, since I can no longer test both for comparison.

Both laptops had the same issues. Just different GPUs and assorted hw.

Something is broken on the list of recognized laptops on acer-wmi and maybe that is why, the /proc/acpi/video directory is no loaded anymore?

All dmesg reports when I "modprobe acer-wmi" on K10.10 and opensuse 11.4 Mx&RC1 is:
acer-wmi: Acer Laptop ACPI-WMI Extras
Registered led device: acer-wmi::mail

and nothing else.

I have some knoppix 6.2 an others, somewhere.. Right now I have at hand Ubuntu 10.04 32bit, 10.10 64 bit and System RescuedCD 1.5.8 with 2.6.32 kernel.

When I get back at home, I might try others.

About Acer laptops,etc ; no offense taken. I was just stating my personal experience and a opinion derived from it. People around me usually brings their laptops issues, so I had seen many different models and brands.

Its just an intuitive feeling, so lacking any rigor or truth value, but seems to me that Acer at least use the same "firmware-acpi" for most models even if they have different hardware. I don't know if by following "style" guidelines for "look&feel" or actually similar firmware code.

So it seems to me that the kernel used some short-cut via the acpi systems, and maybe that is which KDE used those shortcuts until Kubuntu 10.10.

But of course since 10.10, I must load acer-wmi manually, which was automatic in 10.04. And at the same time, 10.10 broke the 3d part on the radeon driver and other bad stuff.

SO right now my speculation goes around acpi bug, video driver bug (the 4810 had an intel gpu but is still possible), Xorg bug or KDE bug.

I lack better kernel/user space knowledge, to be able to pin point the trouble between this many layers, and regular life obligations keep me from dedicating more time. But I'll help in what I can. If you have more suggestions to fix this, please let me know.

If you can pass this issue to the appropriate upstream would be great. But a lot of detective work before that.

I'll get RC1 64bit DVD by tomorrow and then I'll make a fresh install, and try other desktops. I believe only Gnome and XFCE provide the tools for brightness and powersaving facilities or you have another suggestions?

"Its just an intuitive feeling, so lacking any rigor or truth value, but seems
to me that Acer at least use the same "firmware-acpi" for most models even if
they have different hardware. I don't know if by following "style" guidelines
for "look&feel" or actually similar firmware code."

Most vendors do afaik so they can keep their drivers consistent.


I am sorry but I also lack the insight here, I think foremost it would require a fix to the kernel module loading, because without that nothing happens to the brightness anyways, or did I misunderstood you here?
Then atleast the keys works.

I don't know if gnome is better in this regard, you can sure try, another solution is to try the deprecated hal backend on KDE, maybe hal has some mighty magic.
http://forum.kde.org/viewtopic.php?f=14&t=93337

Besides that you can try hunting other bugreports about acer backligt troubles, this doesn't seem to be fixed on opensuse, maybe there is a proper workaround somewhere?

I would like to reiterate an important detail on my openSUSE 11.3 daily driver system. The manual FN+arrow brightness controls do work fine without tweaking. However, the system immediately becomes sluggish and unresponsive, with slow graphics, slow menus, overall lag. This is especially noticeable in a Wine program I use constantly. It becomes unusably sluggish after manually adjusting my brightness. A system reboot is the only way to fix it. Major, major bug.

This sluggishness must be logged somewhere, without that information I can't even think about a person/group to ask or assign this to.

Please check with top, dmesg, ~/.xsession-errors and other files in /var/log if there is something apparently off, if you are unsure you can attach them to the bugreport.

Created attachment 415528 [details]
tarball of log files to identify sluggishness

Hi, sorry it took me so long. 
I am attach before / after logs of top, dmesg, and xession-errors. I rebooted my laptop, took a snapshot of these files, and then changed my brightness with the FN+arrow keys, and then took another snapshot of these same files. The system was definitely sluggish after changing the brightness. I hope this helps.
Thanks!

Hi guys, can we please get this bug marked as confirmed? It is more than confirmed by many users.

There is no 'confirmed' in opensuse bugtracker, also, what are those many users, you both?

Please check out RC2 once it is release and with an empty user, check if the sudden bloating up of .xsession-errors still happens, something is registering and unregistering your keyboard shortcuts, this is propably the slowdown you are noticing.

Thanks for replying. Rephrase: Can this bug please be marked so that it is taken seriously and so that it gets fixed for the release of openSUSE 11.4?  :-)

The many users are: Myself, Ricardo Cornet (from this thread) as well as:
http://forums.opensuse.org/english/get-technical-help-here/laptop/426788-acer-aspire-4810t-adjustable-screen-brightness-not-workin.html
http://forums.opensuse.org/english/get-technical-help-here/laptop/441029-acer-aspire-timeline-4810t-brightness-discharging-battery-how-tune.html

I just tested this bug outside of KDE. I logged into a bare failsafe X terminal, changed the brightness with the Fn+arrows, and then ran a wine program. It was still unusably sluggish. And that's in an environment where there are no window manager keyboard shortcuts. So I suspect a core kernel problem.

Are you using compiz?
Composited KWin?

Have you tried with a clean user?

I googled for you laptop model, brightness and linux, it's a clear mess, I don't think we have the workforce here at opensuse to fix it, also there is no 'please take this serious' setting.


Please also check the following
https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/397617
https://bugs.freedesktop.org/show_bug.cgi?id=29931
https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/446717

I reassign to Xorg, maybe Stephan has an idea or heard about it, if not just fling it back

Hi there, thanks for replying.

No, I don't use Compiz or KDE Compositing. I always disable all 3D desktop effects. I'd just like to reiterate that the last test I did confirmed the same bug using the "Failsafe" session from KDM (not "Failsafe KDE", but rather the failsafe that loads a simple terminal with the X server running. This gives no window manager at all.) so it definitely does not relate to any desktop environment or window manager.

https://help.ubuntu.com/community/AspireTimeline/Fixes
This also talks about the same brightness control issue. There is probably some quick hack, but I don't understand how to implement it.

(In reply to comment #17)
> I reassign to Xorg, maybe Stephan has an idea or heard about it, if not just
> fling it back

Not at all.

Please try setting you driver to intellegacy

http://forums.opensuse.org/english/information-new-users/advanced-how-faq-read-only/438705-opensuse-graphic-card-practical-theory-guide-users.html#post2165620


Still, this is my last reply here, I have no idea, obviously nobody really has a good complete picture, the ubuntu guide suggests messing on pci level to fix this.

Thanks for trying to help. I'm actually already using the intellegacy driver.

Hi everyone, here's a positive update. I found this trick...

setpci -s 00:02.0 F4.B=xx

...where xx = the percentage of brightness. 0 is completely off. 50% is half brightness. And FF is 100%.

It works well on my 4810T running openSUSE 11.4 KDE without causing system sluggishness. So this looks like the way forward. So now:

1. How do we re-route the Fn+Arrow hardware keys run this function instead of their current function? The current function does adjust brightness, but it hangs up the system.
2. How do we make KDE and Gnome power managers run this command? They currently can't control brightness at all.
3. How can I run this command as a regular user without sudo?

Thanks for your help!

Correction-
Change: "50% is half brightness"
To:     "50 is half brightness"

While changing the pci value will work, it is a bit "scary" in that the entire
rest of the system isn't aware that you just changed the brightness value,
which can cause problems later on.

As it seems the acer laptop does not properly handle acpi video brightness
there isn't much I can offer in support of what to do here though, sorry.

*** Bug 680822 has been marked as a duplicate of this bug. ***

*** Bug 680822 has been marked as a duplicate of this bug. ***

> Basically the same problem exists on this system with openSUSE 11.3 too.
Did it ever work as expected?

Does the video.ko kernel driver give you a backlight directory in sys?:
find /sys |grep backlight
?

Please try:
acpi_backlight=vendor
boot parameter and make sure acer-wmi kernel driver gets loaded. Does this help?

I'll be on holidays for some weeks. Please provide further info, I'll look at it when I am back.
As this is probably a mainline problem, someone should open a bug on bugzilla.kernel.org if it does not exist yet and work together with the mainline maintainers.

I'm seeing this same problem on a Thinkpad W510. It was working fine, but some recent updates seem to have broken the screen brightness adjustment. The fn-Home/fn-End keys don't even work anymore.

Hi Thomas, sorry for the delay in replying. I'm running openSUSE 11.4 now, with the 2.6.38 kernel from the opeSUSE KERNEL repo.

>Did it ever work as expected?
Nope

>Does the video.ko kernel driver give you a backlight directory in sys?:
find /sys |grep backlight
?
Yes

>Please try:
acpi_backlight=vendor
boot parameter and make sure acer-wmi kernel driver gets loaded. Does this
help?
Nope, the Fn+arrow keys do nothing when I boot with acpi_backlight=vendor. The acer-wmi module is being loaded correctly.

Thanks very much for any help you can give me with this.

I solved my issues after upgrading my notebook BIOS to the latest version, through the DOS flash program. I don't have Windows installed, and read that the winflash utility has some issues.

I did it by booting a  FreeDOS image where I preloaded the bios utilities. Then loaded/booted  the image with syslinux-memdisk and grub2 from a flashdrive.

What's is strange is that with Ubuntu 10.04 last year everything fine, but since 10.10, and later and of course opensuse the brightness has not been working as it should.

This bios upgrade touched the acpi tables among other things.

Did something change in acpi specs that both the manufacturer and the kernel devs knew, but regular people did not?? And so the older bios were rendered "incompatible" ??

I'm just guessing anyway. but the fact remains that with this bios upgrade the brightness works fine with current kernels and distros.

Two caveats for common people who might read this, The notebook used is a Acer Aspire 3100 and flashing a BIOS is always dangerous. But both use Phoenix BIOS and had the same general issues.

If someone wants the details of how I did the flashing with flashdrive and FreeDOS, just ask. For brevity I'm skipping the details.

I solved my issues after upgrading my notebook BIOS to the latest version, through the DOS flash program. I don't have Windows installed, and read that the winflash utility has some issues.

I did it by booting a  FreeDOS image where I preloaded the bios utilities. Then loaded/booted  the image with syslinux-memdisk and grub2 from a flashdrive.

What's is strange is that with Ubuntu 10.04 last year everything fine, but since 10.10, and later and of course opensuse the brightness has not been working as it should.

This bios upgrade touched the acpi tables among other things.

Did something change in acpi specs that both the manufacturer and the kernel devs knew, but regular people did not?? And so the older bios were rendered "incompatible" ??

I'm just guessing anyway. but the fact remains that with this bios upgrade the brightness works fine with current kernels and distros.

Two caveats for common people who might read this, The notebook used is a Acer Aspire 3100 and flashing a BIOS is always dangerous. But both use Phoenix BIOS and had the same general issues.

If someone wants the details of how I did the flashing with flashdrive and FreeDOS, just ask. For brevity I'm skipping the details.

Thanks for the details.
It's hard to identify what has changed, you could diff the acpi tables if you dumped them with the old BIOS.
But what for..., it works :)

COMMENT: see bug 699798.  Updated for finding on "acpi_backlight=vendor" which also resolved the fn+up/down arrow brightness control.

Although the hardware in the above bug is a Gateway NV79, Gateway (now) uses Acer BIOS and the "acer-wmi" BIOS support.