From: Thomas Gleixner <tglx@linutronix.de>
To: Andi Kleen <ak@suse.de>
Cc: john stultz <johnstul@us.ibm.com>,
Andrew Morton <akpm@linux-foundation.org>,
"Guilherme M. Schroeder" <guilherme@centralinf.com.br>,
lkml <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] Blacklist Dell Optiplex 320 from using the HPET
Date: Sat, 05 May 2007 21:15:01 +0200 [thread overview]
Message-ID: <1178392501.31213.18.camel@localhost.localdomain> (raw)
In-Reply-To: <200705051924.14258.ak@suse.de>
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
next prev parent reply other threads:[~2007-05-05 19:12 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-05-04 21:29 [PATCH] Blacklist Dell Optiplex 320 from using the HPET john stultz
2007-05-04 21:44 ` Andrew Morton
2007-05-04 21:47 ` john stultz
2007-05-04 23:19 ` Andi Kleen
2007-05-04 23:18 ` Andi Kleen
2007-05-04 23:27 ` john stultz
2007-05-05 14:26 ` Thomas Gleixner
2007-05-05 14:30 ` Thomas Gleixner
2007-05-05 15:58 ` Henrique de Moraes Holschuh
2007-05-07 18:59 ` Andreas Mohr
2007-05-07 20:41 ` Henrique de Moraes Holschuh
2007-05-05 17:24 ` Andi Kleen
2007-05-05 19:15 ` Thomas Gleixner [this message]
2007-05-05 22:05 ` Andi Kleen
2007-05-05 22:41 ` Guilherme M. Schroeder
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1178392501.31213.18.camel@localhost.localdomain \
--to=tglx@linutronix.de \
--cc=ak@suse.de \
--cc=akpm@linux-foundation.org \
--cc=guilherme@centralinf.com.br \
--cc=johnstul@us.ibm.com \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox