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    SubjectRe: [PATCH 1/3] clockevents: Retry programming min delta up to 10 times
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    On 19/10/17 13:43, Thomas Gleixner wrote:
    > On Thu, 19 Oct 2017, Matt Redfearn wrote:
    >> unsigned long long clc;
    >> int64_t delta;
    >> + int i;
    >>
    >> - delta = dev->min_delta_ns;
    >> - dev->next_event = ktime_add_ns(ktime_get(), delta);
    >> + for (i = 0;;) {
    > Bah. What's wrong with
    >
    > for (i = 0; i < 10; i++) {
    >
    > ....
    > if (!(dev->set_next_event((unsigned long) clc, dev))
    > return 0;
    > }
    > return -ETIME;
    >
    > Hmm?

    Sure, can make it like that.

    >> + delta = dev->min_delta_ns;
    >> + dev->next_event = ktime_add_ns(ktime_get(), delta);
    >>
    >> - if (clockevent_state_shutdown(dev))
    >> - return 0;
    >> + if (clockevent_state_shutdown(dev))
    >> + return 0;
    >>
    >> - dev->retries++;
    >> - clc = ((unsigned long long) delta * dev->mult) >> dev->shift;
    >> - return dev->set_next_event((unsigned long) clc, dev);
    >> + dev->retries++;
    >> + clc = ((unsigned long long) delta * dev->mult) >> dev->shift;
    > I'd rather make that:
    >
    > delta = 0;
    > for (i = 0; i < 10; i++) {
    > delta += dev->min_delta_ns;
    > dev->next_event = ktime_add_ns(ktime_get(), delta);
    > clc = .....
    > .....
    >
    > That makes it more likely to succeed fast. Hmm?

    That will set the target time to increasing multiples of min_delta_ns in
    the future, right? Sure, it should make it succeed faster - I'll make it
    like that. Are you OK with the arbitrarily chosen 10 retries?

    Thanks,
    Matt

    >
    > Thanks,
    >
    > tglx

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