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Date: Fri, 27 Oct 2000 12:49:47 +0200
From: Vojtech Pavlik <vojtech@suse.cz>
To: Martin Mares <mj@suse.cz>
Cc: "Richard B. Johnson" <root@chaos.analogic.com>,
        Yoann Vandoorselaere <yoann@mandrakesoft.com>,
        linux-kernel@vger.kernel.org
Subject: Re: Possible critical VIA vt82c686a chip bug (private question)
Message-ID: <20001027124947.A476@suse.cz>
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In-Reply-To: <20001027120220.A5741@atrey.karlin.mff.cuni.cz>; from mj@suse.cz on Fri, Oct 27, 2000 at 12:02:20PM +0200
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On Fri, Oct 27, 2000 at 12:02:20PM +0200, Martin Mares wrote:

> > So this is not our problem here. Anyway I guess it's time to hunt for
> > i8259 accesses in the kernel that lack the necessary spinlock, even when
> > they're not probably the cause of the problem we see here.
> 
> BTW what about trying to modify your work-around code to make it
> attempt to read the timer again? This way we could test whether it was
> a race condition during timer read or really timer jumping to a bogus
> value.

Actually if I don't reprogram the timer (and just ignore the value for
example), the work-around code keeps being called again and again very
often (between 1x/minute to 100x/second) after the first failure, even
when the system is idle.

When reprogramming, next failure happens only after stressing the system
again.

So it's not just a race, the impact of the failure on the chip is
permanent and stays till it's reprogrammed.

-- 
Vojtech Pavlik
SuSE Labs
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