Re: [PATCH] Blacklist Dell Optiplex 320 from using the HPET

Thomas Gleixner
2007-05-05T19:12:27Z

On Sat, 2007-05-05 at 19:24 +0200, Andi Kleen wrote:
> > if (!is_hpet_capable())
> > @@ -278,6 +279,14 @@ int __init hpet_enable(void)
> > /* Start the counter */
> > hpet_start_counter();
> >
> > + /* Verify whether hpet counter works */
> > + t1 = hpet_read();
> > + udelay(50);
>
> Are you sure udelay is calibrated at this point? I didn't think so.
> In fact it needs the external clocks and it's a chicken and egg problem.

Oops. You are right. OTOH it does not matter whether it is accurate or
not.

> It might be safer to use a long loop with io port accesses or similar.

Should work as well.

tglx