[ltp] FIXED (but still need debug help): tpb/nvram bewilderment
Richard Neill
linux-thinkpad@linux-thinkpad.org
Tue, 18 Jul 2006 03:08:23 +0100
Daniel Maier wrote:
> On Mon, Jul 17, 2006 at 04:49:00AM +0100, Richard Neill wrote:
>
>>Aargh! even doing "acpi -V" messes it up. No need to blame the battery
>>meter.
>>
>>if you do:
>> cat /proc/acpi/battery/BAT0/state
>>without first having pressed one of the buttons (volume or Fn-Fx), then
>>it will kill off any further use of ACPI or nvram.
>>
>>It seems that you must do a "hardware write" (press a button) to acpi
>>before doing a "software read". (of the battery status)
>
> I have noticed on my T22 that polling /proc/acpi/ makes 1. acpi
> events die and 2. /dev/nvram die. The Fn/volume stuff still workes,
> as its done in hardware.
>
If you cold-boot, then press Fn-F12, and only then read from proc/acpi,
does the nvram still work?
Interestingly:
kernel 2.6.12 -> works
kernel 2.6.16.20, 2.6.17.1 -> fail.
I've filed this as a kernel bug:
http://bugzilla.kernel.org/show_bug.cgi?id=6847
Lastly, as a workaround, do you know of any tasbar battery meter which
runs in its own process, and can be invoked from a shell? KDE's one is
no good, since it starts by default, before I can get to the Fn-F12 key.
Regards,
Richard