[ltp] [patch 08/11] ibm-acpi: extend fan status functions

[Henrique de Moraes Holschuh]

On Mon, 09 Oct 2006, Shem Multinymous wrote:
> On 10/9/06, Henrique de Moraes Holschuh <hmh@hmh.eng.br> wrote:
> >        4. Return speed: unknwon in disengaged mode
> 
> This is slightly annoying when using the anti-pulsing hack, since the
> hack maintains a *roughly* correct tachometer register readout even
> during disengaged mode (since it invokes disengaged mode for just a
> few seconds at a time and RPM does not drift by much).
>
> With this patch, applets reading the tachometer when antipulse is
> being used will get "unknown" instead of a roughly correct value.
> 
> But I guess it should be done anyway.

Yes, it should.

Instead of leaving the breakage in place, we can do other things, like
exporting an average fan speed over a 5s period or somesuch, which would not
be affected immediately by "unknown" readings.  As an extra "Average speed:"
value, of course.  Speed: stays as is.

I could also implement antipulse into ibm-acpi, but I have one strong reason
not to code the antipulse into the kernel driver: it *does* screw up with
operatinal procedures from IBM which (with the latest T40,T41,T42 firmware;
or a patched T43 firmware) are not buggy -- the fixed firmware does away
with all fan pulses but the unclog ones at fan startup, in my experience.

-- 
  "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