Comment 127 for bug 333386

Dear Stefan,

Reading the dmesg log I founded this in line #34:
[ 0.000000] Phoenix BIOS detected: BIOS may corrupt low RAM, working it
around.

Does it mean is there anything wrong with my laptop's BIOS or RAM?

Have you done any progress on the brightness problem?
I'm about installing Karmic beta to test it and will tell you what happens

2009/10/13 Pablo Javier Ferrari Ferrando <email address hidden>

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> 2009/10/12 Stefan Bader <email address hidden>
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> @Pablo, looking at your dmesg it seems you got the option correctly set and
>> it
>> is using the less restrictive mode for the brightness control. So acer-wmi
>> leaves that untouched. Now, when running exactly that mode, can you do a
>> "sudo
>> grep -r . /proc/acpi/video" and attach that output as well?
>>
>> --
>> Acer: Cannot change brightness with 2.6.27-11+ kernel
>> https://bugs.launchpad.net/bugs/333386
>> You received this bug notification because you are a direct subscriber
>> of a duplicate bug.
>>
>> Status in “linux” package in Ubuntu: Fix Released
>> Status in linux in Ubuntu Intrepid: Fix Released
>> Status in linux in Ubuntu Jaunty: Fix Released
>> Status in linux in Ubuntu Karmic: Fix Released
>>
>> Bug description:
>> SRU justification:
>>
>> Impact: After I carelessly pulled in some updates to the ACPI video code,
>> we were faced with some regressions. One was (at least) a certain Acer
>> laptop model that suddenly had no backlight control.
>>
>> Fix: As the ACPI BIOS is broken on a way that only the *wrong* graphics
>> definition will be accepted by acpi-video as the right definition lacks an
>> attribute to be considered, the fix is to have less strict requirements to
>> that check, so the definition for the right graphics device gets accepted (a
>> patch doing that unconditionally, has been submitted upstream and has been
>> acked, but might not make it until 2.6.32). For the stable tree I created
>> more code which makes sure the less strict tests only take effect on that
>> laptop or when the user really wants to.
>>
>> Testcase: Booting on another laptop will not activate the code (which
>> prints a "Using less strict video detection..." message) but will do with
>> "acpi_video_strict_detect=0". In both cases nothing bad happened. The
>> affected laptop boots and selects the new check which gives back the
>> backlight control.
>>
>> ---
>>
>> Since the 2.6.27-11 generic kernel (also in 2.6.27-12) I cannot change the
>> backlight brightness anymore. In the latest kernel, it seems there's no more
>> file in /proc/acpi/video, but GFX0 still apears in 2.6.27-9 where I can
>> still change brightness. I'm new to linux so if you need information give me
>> the command to run. It's an acer 6920G laptop.
>>
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