Thermal state switching

[Alexandre "Sunny" Kovalenko]

On Sun, 2005-02-13 at 12:02 -0800, Nate Lawson wrote:
> Alexandre "Sunny" Kovalenko wrote:
> > Good people,
> > 
> > I was looking at thermal states switching by acpi_thermal.c and it looks
> > like follows (provided that temperature raises and falls slowly and
> > gradually):
> > 
> > NONE =up> AC2 =up> AC1 =up> AC0 =down> NONE                       (1)
> > 
> > I do not know whether this was intentional or not and, for me, something
> > along the lines of
> > 
> > NONE =up> AC2 =up> AC1 =up> AC0 =down> AC1 =down> AC2 =down> NONE (2)
> > 
> > seemed more natural.
> > 
> > If (2) and not (1) was indeed the desired behavior attached patch seems
> > to do the job. If (1) is what was intended, I do apologize for the
> > noise.
> > 
> > I am running -CURRENT from February 3.
> 
> The behavior should be as in #2.  If it isn't, we should fix that. 
> However, I'm not sure how your patch would fix this.  It seems more 
> correct in that we only set the starting time after switching coolers 
> but I don't see how this affects the ACx levels.  Could you explain more?
> 
> Thanks,

I do apologize for delay in answer -- day job decided to catch up with
me.

I guess, I have not explained it properly to start with -- behavior (2)
could not be achieved because start time will be reset as long as you
have _ACx state with the threshold lower then your current temperature.
Or, rather, it could not be achieved if you have non-zero min_runtime.
Moving reset of the start time out of that loop gets everything working
along the lines of (2). Resetting it there did look suspicious to start
with, but since I am just learning my way through ACPI stuff, I have
decided to ask the question instead of filing PR.

Hope this was better explanation then previous one.

-- 
Alexandre "Sunny" Kovalenko (Олександр Коваленко)