lkml.org 
[lkml]   [2011]   [May]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH] ARM: twd: Adjust localtimer frequency withcpufreqnotifiers
    On Mon, 16 May 2011, Colin Cross wrote:
    > On Mon, May 16, 2011 at 7:44 AM, Thomas Gleixner <tglx@linutronix.de> wrote:
    > > On Mon, 16 May 2011, Santosh Shilimkar wrote:
    > >> On 5/14/2011 9:21 PM, Thomas Gleixner wrote:
    > >> Just for my understanding, the clockevents_reconfigure() needs to
    > >> be called with interrupts disabled on that CPU as part of
    > >> the CPUFREQ notifiers. I assume the right place is do it
    > >> in POST notifier after the CPU clock and hence TWD clock is
    > >> updated. Is that right ?
    > >
    > > Yes.
    >
    > Is it safe to only call it in POST? If the frequency is increasing,
    > and the TWD is not updated until after the CPU frequency has changed,
    > it is possible for a clockevent to fire too early. Will that cause
    > problems, or does the clockevent code check against a clocksource to
    > ensure the desired time has been reached? If that is OK, it
    > drastically simplifies the code, because the driver only needs to know
    > the current TWD frequency, not predict a future TWD frequency.

    Yes, the hrtimer code checks against current time, so if it fires too
    early it rearms the timer.

    Thanks,

    tglx


    \
     
     \ /
      Last update: 2011-05-16 18:35    [W:4.026 / U:2.792 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site