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authorNicolai Stange <[email protected]>2017-03-30 22:04:58 +0200
committerJohn Stultz <[email protected]>2017-04-14 13:11:23 -0700
commit6fc46497a9fb283c4f8e8d04ae4f0bf3c0041f7e (patch)
treed9a4985a1ba24c017988ce6c573726d6ba8877b4
parent16c125b6c2c58a77756f099605724a2b11aea2d1 (diff)
x86/uv/time: Set ->min_delta_ticks and ->max_delta_ticks
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 <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Daniel Lezcano <[email protected]> Cc: Richard Cochran <[email protected]> Cc: Prarit Bhargava <[email protected]> Cc: Stephen Boyd <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: [email protected] Cc: Mike Travis <[email protected]> Cc: Dimitri Sivanich <[email protected]> Signed-off-by: Nicolai Stange <[email protected]> Signed-off-by: John Stultz <[email protected]>
-rw-r--r--arch/x86/platform/uv/uv_time.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/platform/uv/uv_time.c b/arch/x86/platform/uv/uv_time.c
index 2ee7632d4916..b082d71b08ee 100644
--- a/arch/x86/platform/uv/uv_time.c
+++ b/arch/x86/platform/uv/uv_time.c
@@ -390,9 +390,11 @@ static __init int uv_rtc_setup_clock(void)
clock_event_device_uv.min_delta_ns = NSEC_PER_SEC /
sn_rtc_cycles_per_second;
+ clock_event_device_uv.min_delta_ticks = 1;
clock_event_device_uv.max_delta_ns = clocksource_uv.mask *
(NSEC_PER_SEC / sn_rtc_cycles_per_second);
+ clock_event_device_uv.max_delta_ticks = clocksource_uv.mask;
rc = schedule_on_each_cpu(uv_rtc_register_clockevents);
if (rc) {