Re: radeon breaks with clocksource_jiffies

From: john stultz-lkml
Date: Fri Feb 23 2007 - 17:10:37 EST


On 2/23/07, David Miller <davem@xxxxxxxxxxxxx> 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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