[ltp] EC dump information for A3x/X3x/T3x Thinkpads: results

[Henrique de Moraes Holschuh]

On Mon, 28 Aug 2006, Henrique de Moraes Holschuh wrote:
> This information will be used to improve ibm-acpi to do the right thing, and
> return all available sensors in newer Thinkpads (which support up to 16
> sensors, as we know from ThinkWiki, although we have had no reports of
> models with more than 11 sensors so far).

Here's what has been found by this study:

Thinkpads with the new-style EC (those which, after being updated to the
latest BIOS and EC firmware, have the EC firmware revision DMI string)
support the 16 sensors sanely: either the sensors are supported, and those
that do not exist read 0x80, or the entire C0-C7 range is always zero.

Older ThinkPads, with older style ECs, can have extraneous information in
registers C0-C7 (eg. T20).

I have written a patch for ibm_acpi, and I am testing it.  I will post it
here and to the wiki for some beta testing later on.  The patch *requires*
a DMI patch that is included in the tp_smapi tarball, and already accepted
for -mm kernels.

-- 
  "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