hi,
I migrated from (k)ubuntu to debian few months ago. I have now 99% working laptop for 24/7 use, but there is still one missing part - sound. It's known problem of Toshiba P100 series and it require loading custom DSDT file to kernel at start. There is bunch of guides how to do this and I after recompiling DSDT I get it working in Ubuntu. It survived with little changes and reloading also multiple kernel and bios upgrades of my notebook through year. But when I migrated to debian, custom DSDT loading doesn't work anymore. I'm running Lenny 32-bit and tried kernels 2.6.19 - 2.6.22, none of them wants to load DSDT I provide. Only option to have working sound is "acpi=off" option at initrd line in bootloader. Here is guide I follow>

Code:
# acpifix
apt-get install iasl
cd toInstall/acpifix
cp dsdt.aml /etc/initramfs-tools/DSDT.aml
dpkg-reconfigure linux-image-$(uname -r)


dsdt.aml file is 100% working customized dsdt file that worked for me in ubuntu (same bios on machine)
there is also variant tu substitute last line in this script with "update-initramfs -u", or "mkinitramfs `uname -r` -o /boot/initrd.img-`uname -r`" but I think effect is the same

after this patch, OS boots properly with acpi enabled (as before without custom DSDT), but sound simply doesn't work (it is acting like no custom DSDT is loaded when acpi is on)

edit> and one more thing that maybe has a relationship with this issue. when I set in alsamixer Master and PCM volume sliders both to 100%, I experience very low quality sound. when I decrease PCM to for example 85% and increase manual volume control on my laptop to get the same volume level, sound quality is much better. this is when I'm in linux with acpi=off, when I boot to winXP, sound quality is OK.

reinstall of alsa base helped, now all works like a charm