lkml.org 
[lkml]   [2005]   [Dec]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] x86_64: Display HPET timer option
From
Date
Hey Andi,

I looked a bit better at what happens (by adding a bunch of printk's in
drivers/char/hpet.c) and it seems that read_counter(&hpet->hpet_mc);
always returns -1 and that causes the following loop in
static unsigned long hpet_calibrate(struct hpets *hpetp)
to endlessly loop while having local_irq_save(flags).

do {
m = read_counter(&hpet->hpet_mc);
write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);
} while (i++, (m - start) < count);

count is 0xe9 and start and (m - start) is 0.

What could be the reason that read_counter(&hpet->hpet_mc) is and stays
-1 ?


- Erwin

On Thu, 2005-12-01 at 22:18 +0100, Andi Kleen wrote:
> On Thu, Dec 01, 2005 at 10:06:37PM +0100, Erwin Rol wrote:
> > On Thu, 2005-12-01 at 21:43 +0100, Andi Kleen wrote:
> > > On Thu, Dec 01, 2005 at 12:30:03PM -0800, Zwane Mwaikambo wrote:
> > > > On Thu, 1 Dec 2005, Linus Torvalds wrote:
> > > >
> > > > > On Thu, 1 Dec 2005, Zwane Mwaikambo wrote:
> > > > > >
> > > > > > Currently the HPET timer option isn't visible in menuconfig.
> > > > >
> > > > > Do you want it to?
> > > > >
> > > > > Why would you ever compile it out?
> > > >
> > > > For timer testing purposes i sometimes would like not to use the HPET.
> > > > Would a runtime switch be preferred?
> > >
> > > nohpet already exists.
> > >
> >
> > And luckily it does cause without "nohpet" i can't boot my shuttle
> > ST20G5, the NMI watchdog kills it because ti hangs when initializing the
> > hpet. If the nmi watchdog is off it just hangs for ever.
>
> Can you give details on the machine? lspci, dmidecode, acpidmp output,
> boot log from the hang case?
>
> Then perhaps it can be blacklisted or the failure otherwise avoided.
>
> [Looks like I finally need to add DMI decode support to x86-64 too :-/]
>
> -Andi
>
>

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-12-09 20:58    [W:1.072 / U:0.016 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site