Terence, First, I'm delighted to hear from nvidia -- thanks for reaching out to the Linux community. a couple of observations... drivers/acpi/*.c in general, and video.c in particular, are meant to implement what is documented in the ACPI specification. Linux has moved the vendor specific drivers (that may use ACPI, or use vendor-specific ACPI extensions) to drivers/platform/x86/*.c That is where I'd generally expect an nvidia-specific ACPI extension to live. Is there any public documentationon how NVIF is supposed to operate? I have a new snappy Sony laptop that has both nvidia and intel graphics, and it has an NVIF. I'm certain that Linux has no idea how to switch between "Stamina" and "Speed" modes... But I also have a Lenovo T61 with only Intel graphics, and it still has an NVIF. (presumably Lenovo ships one BIOS for both their Intel and Nvidia based T61's...) What happens with NVIF in this case? thanks, -Len -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html