Re: [RFC][PATCH] new timeofday core subsystem (v.A0)

john stultz
2004-09-03T19:50:04Z

On Fri, 2004-09-03 at 00:43, George Anzinger wrote:
> john stultz wrote:
> > On Thu, 2004-09-02 at 17:47, Christoph Lameter wrote:
> >
> >>On Thu, 2 Sep 2004, john stultz wrote:
> > read(): Rather then just giving the address of the register, the read
> > call allows for timesource specific logic. This lets us use jiffies as a
> > timesource, or in cases like the ACPI PM timesource, where the register
> > must be read 3 times in order to ensure a correct value is latched, we
> > can avoid having to include that logic into the generic code, so it does
> > not affect systems that do not use or have that timesource.
>
> I am not convince that 3 reads are in fact needed. In fact, I am amost certain
> that two is more than enough. In fact, it takes so long to read it that I just
> use one read and a sanity check in the HRT code. Here is the code I use:

[snip]

I'd have to defer to Dominik (acpi-pm author) for that. But the case
remains, to get a "good" value, you have to do more then just give
access to the raw register.

thanks
-john