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)