From mboxrd@z Thu Jan 1 00:00:00 1970 From: tglx@linutronix.de (Thomas Gleixner) Date: Sat, 14 May 2011 17:51:21 +0200 (CEST) Subject: [PATCH] ARM: twd: Adjust localtimer frequency withcpufreqnotifiers In-Reply-To: References: <1290060899-9786-1-git-send-email-ccross@android.com> <4D70BE9D.4000507@stericsson.com> <4D714C17.7080102@gmail.com> <7e9fafa016bfe536ccc373fc2cc7ba61@mail.gmail.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, 13 May 2011, Colin Cross wrote: > On Fri, May 13, 2011 at 3:02 AM, Thomas Gleixner 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