Commit-ID: 6fc46497a9fb283c4f8e8d04ae4f0bf3c0041f7e
Gitweb: http://git.kernel.org/tip/6fc46497a9fb283c4f8e8d04ae4f0bf3c0041f7e
Author: Nicolai Stange <nicstange@xxxxxxxxx>
AuthorDate: Thu, 30 Mar 2017 22:04:58 +0200
Committer: John Stultz <john.stultz@xxxxxxxxxx>
CommitDate: Fri, 14 Apr 2017 13:11:23 -0700
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 <mingo@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
Cc: Richard Cochran <richardcochran@xxxxxxxxx>
Cc: Prarit Bhargava <prarit@xxxxxxxxxx>
Cc: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: x86@xxxxxxxxxx
Cc: Mike Travis <travis@xxxxxxx>
Cc: Dimitri Sivanich <sivanich@xxxxxxx>
Signed-off-by: Nicolai Stange <nicstange@xxxxxxxxx>
Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx>
---
arch/x86/platform/uv/uv_time.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/x86/platform/uv/uv_time.c b/arch/x86/platform/uv/uv_time.c
index 2ee7632..b082d71 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) {
--
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