Messages in this thread | | | Date | Wed, 8 Feb 2023 23:22:40 +0100 | From | Matthias Brugger <> | Subject | Re: [PATCH 1/3] time/sched_clock: Export sched_clock_register() |
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On 08/02/2023 20:45, Krzysztof Kozlowski wrote: > On 08/02/2023 20:41, Matthias Brugger wrote: >> >> >> On 08/02/2023 15:24, Krzysztof Kozlowski wrote: >>> On 08/02/2023 10:48, walter.chang@mediatek.com wrote: >>>> From: Chun-Hung Wu <chun-hung.wu@mediatek.com> >>>> >>>> clocksource driver may use sched_clock_register() >>>> to resigter itself as a sched_clock source. >>>> Export it to support building such driver >>>> as module, like timer-mediatek.c >>>> >>>> Signed-off-by: Chun-Hung Wu <chun-hung.wu@mediatek.com> >>>> --- >>>> kernel/time/sched_clock.c | 4 ++-- >>>> 1 file changed, 2 insertions(+), 2 deletions(-) >>>> >>>> diff --git a/kernel/time/sched_clock.c b/kernel/time/sched_clock.c >>>> index 8464c5acc913..8e49e87d1221 100644 >>>> --- a/kernel/time/sched_clock.c >>>> +++ b/kernel/time/sched_clock.c >>>> @@ -150,8 +150,7 @@ static enum hrtimer_restart sched_clock_poll(struct hrtimer *hrt) >>>> return HRTIMER_RESTART; >>>> } >>>> >>>> -void __init >>>> -sched_clock_register(u64 (*read)(void), int bits, unsigned long rate) >>>> +void sched_clock_register(u64 (*read)(void), int bits, unsigned long rate) >>> >>> Is there a non-init caller? >>> >>>> { >>>> u64 res, wrap, new_mask, new_epoch, cyc, ns; >>>> u32 new_mult, new_shift; >>>> @@ -223,6 +222,7 @@ sched_clock_register(u64 (*read)(void), int bits, unsigned long rate) >>>> >>>> pr_debug("Registered %pS as sched_clock source\n", read); >>>> } >>>> +EXPORT_SYMBOL_GPL(sched_clock_register); >>> >>> Where is the module using it? >>> >>> You need to bring users of these two changes, not just prepare something >>> for your out of tree patches. >>> >> >> I'd propose to add at least one driver that will need these changes, to make it >> clear why you need that. > > ... and actually test if the system works fine when booted from such > clocksource as a module. I have doubts that and unfortunately folks > working on GKI like to put whatever stuff from mainline into modules > even if it does not make sense for us (see long time ago discussion > about pinctrl drivers). >
Yes thinking about it twice, it makes only sense if the Arm architecture timer is running. Otherwise the system will hang on boot. I know that older MediaTek devices had problems with that...
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