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Message-ID: <1f1b08da0702231410x24728480n463d08540c1c665f@mail.gmail.com>
Date: Fri, 23 Feb 2007 14:10:07 -0800
From: "john stultz-lkml" <johnstul.lkml@gmail.com>
To: "David Miller" <davem@davemloft.net>
Subject: Re: radeon breaks with clocksource_jiffies
Cc: linux-kernel@vger.kernel.org
In-Reply-To: <20070223.140328.74752162.davem@davemloft.net>
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On 2/23/07, David Miller <davem@davemloft.net> wrote:
> > While probeing PLL information via radeon_get_pllinfo(), it does a
> > "gettimeofday(); do_something(); gettimeofday();" type sequence
> > explicitly with interrupts disabled, so ends up with a zero
> > measurement which then results in a bunch of divisions by zero.
> >
> > We should decide whether gettimeofday() can be expected to advance with
> > interrupts disabled, or that clocksource_jiffies is simply invalid because
> > of this behavior.
>
> Actually, with clocksource based gettimeofday(), radeon built-in cannot
> work at all.
>
> The reason is that the clocksource code will not jump over to a
> clock source other than clocksource_jiffies until the late initcalls
> are run, because of this code:

Check out the patch I sent out yesterday. It should resolve this problem.

thanks
-john
-
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