Re: [PATCH] ARM: twd: Adjust localtimer frequencywithcpufreqnotifiers
From: Thomas Gleixner
Date: Sat May 14 2011 - 11:51:41 EST
On Fri, 13 May 2011, Colin Cross wrote:
> On Fri, May 13, 2011 at 3:02 AM, Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
> > /**
> > + * clockevents_reconfigure - Reconfigure and reprogram a clock event device.
> > + * @dev: device to modify
> > + * @freq: new device frequency
> > + * @secr: guaranteed runtime conversion range in seconds
> > + *
> > + * Reconfigure and reprogram a clock event device in oneshot
> > + * mode. Must only be called from low level idle code where
> > + * interaction with hrtimers/nohz code etc. is not possible and
> > + * guaranteed not to conflict. Must be called with interrupts
> > + * disabled!
> > + * Returns 0 on success, -ETIME when the event is in the past or
> > + * -EINVAL when called with invalid parameters.
> > + */
> We need to call this from a cpufreq notifier with interrupts disabled,
> not from idle.
That works as well. Comments needs update. The important thing is that
neither a timer interrupt nor a hrtimer function should interfere on
that very cpu.
Thanks,
tglx