[ltp] Getting rid of uhci_hcd on Ubuntu

[Henrique de Moraes Holschuh]

On Mon, 22 Jun 2009, Florian Reitmeir wrote:
> The common missunderstanding is the mixup between C1-C3 of ACPI and
> C1-C10 of the CPU. while its true that most cpus support C4 or higher.
> ACPI just supports as highest level C3, and this C3 is not the same as
> the cpu C3. (the bios hides the hardware sleepstate from the os)

ACPI can support up to C7.  Now, *ThinkPads* usually do C1, C2 and C3 when
on AC power, and C1, C2 and C4 when on battery.  Some might also do C1-C4
when on battery (but Linux will just almost never use C3 in that case
anyway...).

As you said, the ACPI Cx state maps to some CPU Cy state, and x doesn't have
to be equal to y.  The BIOS defines this mapping, and it _can_ change (but I
don't think ThinkPads do that, AFAIK the ThinkPad BIOS just expose C4
instead of reprogramming C3).

-- 
  "One disk to rule them all, One disk to find them. One disk to bring
  them all and in the darkness grind them. In the Land of Redmond
  where the shadows lie." -- The Silicon Valley Tarot
  Henrique Holschuh