Comment 49 for bug 573984

Updated to Ubuntu 10.10 today on my Gateway NV59

Screen brightness still can not be adjusted without causing other problems. Only solution causes CPU to run hot and without hyperthreading. Here are the results of various parameters for grub:

#GRUB_CMDLINE_LINUX_DEFAULT="quiet splash nolapic acpi_backlight=vendor"
#result: brightness doesn't change; oncreen display disappears
#GRUB_CMDLINE_LINUX="acpi=ht"
#result: brightness doesn't change;
#GRUB_CMDLINE_LINUX="acpi=off"
#result: brightness changes correctly; no onscreen display; no CPU temperature reading; no hyperthreading
#GRUB_CMDLINE_LINUX="acpi_generic_hotkey"
#result: pressing hot keys slows down mouse
#GRUB_CMDLINE_LINUX="acpi=strict"
#result: brightness does not change
#GRUB_CMDLINE_LINUX="acpi_osi=Linux"
#result: brightness does not change; onscreen display disappears
#GRUB_CMDLINE_LINUX="acpi_osi="
#result: brightness does not change; onscreen display disappears
#GRUB_CMDLINE_LINUX="acpi=noirq"
#result: brightness does not change; onscreen display disappears; mouse very slow after using brigthness up down function keys
#GRUB_CMDLINE_LINUX="acpi=noacpi"
#result: brightness does not change;
#GRUB_CMDLINE_LINUX="acpi_backlight=vendor"
#result: brightness does not change; onscreen display disappears