[ltp] T61 brightness/volume

[Alan Wood]

I've been perusing the list for a couple of months now for help with 
lingering issues with my Thinkpad T61 (14" widescreen, Intel GMA).  I just 
upgraded from BIOS 1.26 to 2.07 but that seemed to have no effect.
I've seen lots of people who have similar prolems and attempted nearly all 
the solutions to no avail.  I'm running Fedora 8, kernel 2.6.23.9-85.fc8

First Brightness:
out of the box, brightness controls (fn-home, fn-end) work fine in the Grub 
menu.  Once the kernel is booted the story is different.
I've tried the stock thinkpad_acpi that came with F8 (0.16) and I compiled 
thinkpad_acpi 0.18-20071203 for comparison.  both gave me the same results.
Namely, I get the /proc/acpi/ibm/brightness interface.  echoing commands to 
that works fine (TPB even pops up when I issue brightness changes from 
the cli).
However when I use the fn keys to control brightness I get a different 
result.  Under X (KDE, kmilo disabled), the contents of 
/proc/acpi/ibm/brightness changes accordingly and the TPB osd shows up, 
but the brightness does not actually change.  In the console obviously TPB 
does not show up but the proc interface shows a change despite the screen 
not changing brightness.
I have played with the brightness_enable and brightness_mode options for 
thinkpad_acpi but to no avail.  the only difference comes in the dmesg 
output for insmod.  auto gives me:
thinkpad_acpi: CMOS NVRAM (13) and EC (0) do not agree on display brightness level
while defined modes give me:
thinkpad_acpi: detected a 16-level brightness capable ThinkPad


with sound my issues are slightly different.  I disabled pulseaudio 
entirely and made sure that gconf saw PCM as the default mixer (using 
alsa).  still the hardware keys don't do much.
again I get the /proc/acpi/ibm/volume interface.  I can echo commands in 
there and they both stick and cause TPB to show an osd but have no effect 
on actual sound ouput.  pressing the hardware buttons has no effect 
whatsoever now, but with my original install the mute button did at least 
register (not sure which changed caused that to stop working).


I read the kernel thread 
http://thread.gmane.org/gmane.linux.kernel/591037/focus=591045
for insight but did't find anything much agreed upon.
wondering what the status was on these things.  are we just waiting on 
fixes from Lenovo?  are there workarounds that make these things work 
correctly (say, capturing acpi events?).  is there something I'm missing?
-alan