Re: udelay function delays the wrong time interval in multiprocessorsystem, if ARCH_HAS_READ_CURRENT_TIMER is not defined and on current timer is used.
From: chpoph
Date: Fri Mar 15 2013 - 23:32:51 EST
On Sat, Mar 16, 2013 at 2:14 AM, Russell King - ARM Linux
<linux@xxxxxxxxxxxxxxxx> wrote:
> We don't support different CPUs running at different frequencies with
> the delay loop. Sorry.
Does it means that a timer-based delay implementation must be used to
get an accurate delay in SMP. I think it should print a warning
message if the CPU delay loop is used in SMP. In my system, the wrong
delay interval fluctuated with CPU frequencies caused a control
problem.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/