The following commit has been merged into the timers/urgent branch of tip:
Commit-ID: 94cff94634e506a4a44684bee1875d2dbf782722 Gitweb: https://git.kernel.org/tip/94cff94634e506a4a44684bee1875d2dbf782722 Author: Sebastian Andrzej Siewior bigeasy@linutronix.de AuthorDate: Fri, 04 Apr 2025 15:31:16 +02:00 Committer: Thomas Gleixner tglx@linutronix.de CommitterDate: Mon, 05 May 2025 15:34:49 +02:00
clocksource/i8253: Use raw_spinlock_irqsave() in clockevent_i8253_disable()
On x86 during boot, clockevent_i8253_disable() can be invoked via x86_late_time_init -> hpet_time_init() -> pit_timer_init() which happens with enabled interrupts.
If some of the old i8253 hardware is actually used then lockdep will notice that i8253_lock is used in hard interrupt context. This causes lockdep to complain because it observed the lock being acquired with interrupts enabled and in hard interrupt context.
Make clockevent_i8253_disable() acquire the lock with raw_spinlock_irqsave() to cure this.
[ tglx: Massage change log and use guard() ]
Fixes: c8c4076723dac ("x86/timer: Skip PIT initialization on modern chipsets") Signed-off-by: Sebastian Andrzej Siewior bigeasy@linutronix.de Signed-off-by: Thomas Gleixner tglx@linutronix.de Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/20250404133116.p-XRWJXf@linutronix.de --- drivers/clocksource/i8253.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/drivers/clocksource/i8253.c b/drivers/clocksource/i8253.c index 39f7c2d..b603c25 100644 --- a/drivers/clocksource/i8253.c +++ b/drivers/clocksource/i8253.c @@ -103,7 +103,7 @@ int __init clocksource_i8253_init(void) #ifdef CONFIG_CLKEVT_I8253 void clockevent_i8253_disable(void) { - raw_spin_lock(&i8253_lock); + guard(raw_spinlock_irqsave)(&i8253_lock);
/* * Writing the MODE register should stop the counter, according to @@ -132,8 +132,6 @@ void clockevent_i8253_disable(void) outb_p(0, PIT_CH0);
outb_p(0x30, PIT_MODE); - - raw_spin_unlock(&i8253_lock); }
static int pit_shutdown(struct clock_event_device *evt)