tick: Do not set device to detached state in tick_shutdown()

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[ Upstream commit fe2a449a45 ]

tick_shutdown() sets the state of the clockevent device to detached
first and the invokes clockevents_exchange_device(), which in turn
invokes clockevents_switch_state().

But clockevents_switch_state() returns without invoking the device shutdown
callback as the device is already in detached state. As a consequence the
timer device is not shutdown when a CPU goes offline.

tick_shutdown() does this because it was originally invoked on a online CPU
and not on the outgoing CPU. It therefore could not access the clockevent
device of the already offlined CPU and just set the state.

Since commit 3b1596a21f tick_shutdown() is called on the outgoing CPU, so
the hardware device can be accessed.

Remove the state set before calling clockevents_exchange_device(), so that
the subsequent clockevents_switch_state() handles the state transition and
invokes the shutdown callback of the clockevent device.

[ tglx: Massaged change log ]

Fixes: 3b1596a21f ("clockevents: Shutdown and unregister current clockevents at CPUHP_AP_TICK_DYING")
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/all/20250906064952.3749122-2-maobibo@loongson.cn
Signed-off-by: Sasha Levin <sashal@kernel.org>

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This commit is contained in:

Bibo Mao 2025-09-06 14:49:51 +08:00 • committed by Greg Kroah-Hartman

parent c4fa8cf7ce

commit f1c3bb6b40

3 changed files with 7 additions and 13 deletions

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2

kernel/time/clockevents.c

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16

kernel/time/tick-common.c

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2

kernel/time/tick-internal.h

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