From: Andi Kleen <ak@suse.de>
To: tglx@linutronix.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, 5 May 2007 19:24:14 +0200 [thread overview]
Message-ID: <200705051924.14258.ak@suse.de> (raw)
In-Reply-To: <1178375214.31213.13.camel@localhost.localdomain>
> 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.
It might be safer to use a long loop with io port accesses or similar.
-Andi
> + if (t1 == hpet_read()) {
> + printk(KERN_WARNING "HPET counter is defect\n");
> + goto out_nohpet;
> + }
> +
> /* Initialize and register HPET clocksource
> *
> * hpet period is in femto seconds per cycle
>
>
>
next prev parent reply other threads:[~2007-05-05 17:24 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 [this message]
2007-05-05 19:15 ` Thomas Gleixner
2007-05-05 22:05 ` Andi Kleen
2007-05-05 22:41 ` Guilherme M. Schroeder
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