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Subject[PATCH v2] time: Fix sleeptime injection for non-stop clocksource & persistent clock
Date
Currently, for both non-stop clocksource and persistent clock
there is a corner case, when a driver failed to go suspend mode.
rtc_resume() injects the sleeptime as timekeeping_rtc_skipresume()
returned 'false'(sleeptime_injected=false) due to which we can
see mismatch in timestamps between system clock and other timers.

Fix this by updating sleeptime_injected=true for both non-stop
clocksource and persistent clock.

Success case:
------------
{sleeptime_injected=true}
rtc_suspend() => timekeeping_suspend() => timekeeping_resume() =>
rtc_resume()

Failure case:
------------
{failure in sleep path} {sleeptime_injected=false}
rtc_suspend() => rtc_resume()

Signed-off-by: Mukesh Ojha <mojha@codeaurora.org>
---
Changes in v2:
* Updated the commit text.
* Removed extra variable and used the earlier static
variable 'sleeptime_injected'.

kernel/time/timekeeping.c | 11 +++++++++++
1 file changed, 11 insertions(+)

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 49cbcee..2754c1b 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -1610,6 +1610,17 @@ static void __timekeeping_inject_sleeptime(struct timekeeper *tk,
*/
bool timekeeping_rtc_skipresume(void)
{
+ struct timekeeper *tk = &tk_core.timekeeper;
+ /*
+ * This is to ensure that we don't end up injecting
+ * the sleeptime via rtc_resume() for non-stop clocksource
+ * when we fail to sleep.
+ */
+ if (!sleeptime_injected)
+ sleeptime_injected = ((tk->tkr_mono.clock->flags &
+ CLOCK_SOURCE_SUSPEND_NONSTOP) ||
+ (persistent_clock_exists)) ? true : false;
+
return sleeptime_injected;
}

--
Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center,
Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project
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