Re: [PATCH 4/4] rtc: Extend timeout for waiting for UIP to clear to 1s

From: Mateusz Jończyk
Date: Sat Nov 18 2023 - 14:26:10 EST


W dniu 17.11.2023 o 07:32, Mario Limonciello pisze:
> Specs don't say anything about UIP being cleared within 10ms. They
> only say that UIP won't occur for another 244uS. If a long NMI occurs
> while UIP is still updating it might not be possible to get valid
> data in 10ms.
>
> This has been observed in the wild that around s2idle some calls can
> take up to 480ms before UIP is clear.
>
> Adjust callers from outside an interrupt context to wait for up to a
> 1s instead of 10ms.
>
> Reported-by: xmb8dsv4@xxxxxxxxx
> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217626
> Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
> ---
> arch/x86/kernel/rtc.c | 2 +-
> drivers/base/power/trace.c | 2 +-
> drivers/rtc/rtc-cmos.c | 2 +-
> drivers/rtc/rtc-mc146818-lib.c | 2 +-
> 4 files changed, 4 insertions(+), 4 deletions(-)

Consider:

Fixes: ec5895c0f2d8 ("rtc: mc146818-lib: extract mc146818_avoid_UIP")

If you would like to Cc: stable this patch,

commit d2a632a8a117 ("rtc: mc146818-lib: reduce RTC_UIP polling period")

is a prerequisite.

Greetings,

Mateusz