I have a Toshiba P105-S6197 with BIOS V3.30 and the Intel HD-Audio
82801G ICH7 sound hardware.

With kernel 2.6.22 I had to give it the argument acpi_osi=!Linux before
sound would work. (Otherwise, there would be no obvious errors, but only
silence.)

With kernel 2.6.23.1 this trick didn't work. However, if in
drivers/acpi/ec.c I comment out the if (ACPI_SUCCESS(status)) ... else
.... part, lines 879 through 892, sound starts working again.

Mark