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um: time: Fix read_persistent_clock64() in time-travel 

In time-travel mode, we've relied on read_persistent_clock64()
being called only once at system startup, but this is both the
right thing to call from the pseudo-RTC, and also gets called
by the timekeeping core during suspend/resume.

Thus, fix this to always fall make use of the time_travel_time
in any time-travel mode, initializing time_travel_start at boot
to the right value depending on the time-travel mode.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
This commit is contained in:
Johannes Berg 2020-12-02 20:58:05 +01:00 committed by Richard Weinberger
parent 49da38a3ef
commit 2701c1bd91
1 changed files with 20 additions and 3 deletions
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23
arch/um/kernel/time.c
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@ -676,10 +676,8 @@ void read_persistent_clock64(struct timespec64 *ts)
{
long long nsecs;
if (time_travel_start_set)
if (time_travel_mode != TT_MODE_OFF)
nsecs = time_travel_start + time_travel_time;
else if (time_travel_mode == TT_MODE_EXTERNAL)
nsecs = time_travel_ext_req(UM_TIMETRAVEL_GET_TOD, -1);
else
nsecs = os_persistent_clock_emulation();
@ -689,6 +687,25 @@ void read_persistent_clock64(struct timespec64 *ts)
void __init time_init(void)
{
#ifdef CONFIG_UML_TIME_TRAVEL_SUPPORT
switch (time_travel_mode) {
case TT_MODE_EXTERNAL:
time_travel_start = time_travel_ext_req(UM_TIMETRAVEL_GET_TOD, -1);
/* controller gave us the *current* time, so adjust by that */
time_travel_ext_get_time();
time_travel_start -= time_travel_time;
break;
case TT_MODE_INFCPU:
case TT_MODE_BASIC:
if (!time_travel_start_set)
time_travel_start = os_persistent_clock_emulation();
break;
case TT_MODE_OFF:
/* we just read the host clock with os_persistent_clock_emulation() */
break;
}
#endif
timer_set_signal_handler();
late_time_init = um_timer_setup;
}