Mailinglist Archive: opensuse-bugs (3543 mails)

< Previous Next >
[Bug 578578] Bright control not working at all with Acer Extensa 5635Z

--- Comment #17 from Joey Lee <jlee@xxxxxxxx> 2011-09-15 12:11:53 UTC ---
(In reply to comment #16)
Hm, on kernel bugzilla, there is the additional "resolved documented" state
bugs which would be nice for this one as well.

If I understood Joey Lee correctly there is a Windows brightness driver which
more and more OEMs are using to which we are not 100% compatible.
As there fortunately is an easy workaround, I resolve the bug.

Yes, more and more acer machine applied WDDM driver, the spec is here:

Unfortunately, acer's ODM didn't fully follow this microsoft's spec, because
the _BCM must works per this spec's definition.

If there is a more general problem with brightness interfaces (on this one
without acpi_osi=Linux on others this might not work), this sounds as it
get discussed on the acpi or x86_platform mailing list or in a bug with the goal to get things work mainline.

I could imagine there are similar bugs there where you could attach your
acpidump output as another example and offer testing if you want to help.
it helps that someone finds what's missing on Linux and can get fixed/tested
the kernel guy does not have such HW.

Linux Kernel bugzilla still crash, the following is a comment I added in
upstream kernel bugzilla, for reference:

Unfortunately, this is a BIOS bug because the standard _BCM doesn't work on
this machine! You are not the first one, please see:

Acer Travelmate 5760 and Acer Aspire 5750G have the same problem like your

Microsoft have a new brightness control spec for Windows Vista and Windows 7:

The problem is:

On windows Vista or 7, WDDM driver will control brightness but not through
_BCM. In the spec, OEM still need keep the _BCM works fine for compliance with
Linux or XP or any other OS doesn't have WDDM driver.

But, Acer's OEM didn't follow it, and Acer also didn't follow spec to test
I already sent many email to Acer PM, but they didn't response me. :-(

Could you please give me your Packard Bell Notebook mode name? And please file
a bug on

Even I have no solution at this moment...

Configure bugmail:
------- You are receiving this mail because: -------
You are on the CC list for the bug.

< Previous Next >