• Nicolai Stange's avatar
    x86/uv/time: Set ->min_delta_ticks and ->max_delta_ticks · 6fc46497
    Nicolai Stange authored
    In preparation for making the clockevents core NTP correction aware,
    all clockevent device drivers must set ->min_delta_ticks and
    ->max_delta_ticks rather than ->min_delta_ns and ->max_delta_ns: a
    clockevent device's rate is going to change dynamically and thus, the
    ratio of ns to ticks ceases to stay invariant.
    
    Currently, the x86's uv rtc clockevent device is initialized as follows:
    
      clock_event_device_uv.min_delta_ns = NSEC_PER_SEC /
                                     sn_rtc_cycles_per_second;
      clock_event_device_uv.max_delta_ns = clocksource_uv.mask *
                                     (NSEC_PER_SEC / sn_rtc_cycles_per_second);
    
    This translates to a ->min_delta_ticks value of 1 and a ->max_delta_ticks
    value of clocksource_uv.mask.
    
    Initialize ->min_delta_ticks and ->max_delta_ticks with these values
    respectively.
    
    This patch alone doesn't introduce any change in functionality as the
    clockevents core still looks exclusively at the (untouched) ->min_delta_ns
    and ->max_delta_ns. As soon as this has changed, a followup patch will
    purge the initialization of ->min_delta_ns and ->max_delta_ns from this
    driver.
    
    Cc: Ingo Molnar <mingo@redhat.com>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
    Cc: Richard Cochran <richardcochran@gmail.com>
    Cc: Prarit Bhargava <prarit@redhat.com>
    Cc: Stephen Boyd <sboyd@codeaurora.org>
    Cc: "H. Peter Anvin" <hpa@zytor.com>
    Cc: x86@kernel.org
    Cc: Mike Travis <travis@sgi.com>
    Cc: Dimitri Sivanich <sivanich@sgi.com>
    Signed-off-by: default avatarNicolai Stange <nicstange@gmail.com>
    Signed-off-by: default avatarJohn Stultz <john.stultz@linaro.org>
    6fc46497
uv_time.c 9.97 KB