From: Fabrice Gasnier fabrice.gasnier@foss.st.com
[ Upstream commit f4a8f561d08e39f7833d4a278ebfb12a41eef15f ]
When enabling PREEMPT_RT, the gpio_keys_irq_timer() callback runs in hard irq context, but the input_event() takes a spin_lock, which isn't allowed there as it is converted to a rt_spin_lock().
[ 4054.289999] BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48 [ 4054.290028] in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 0, name: swapper/0 ... [ 4054.290195] __might_resched+0x13c/0x1f4 [ 4054.290209] rt_spin_lock+0x54/0x11c [ 4054.290219] input_event+0x48/0x80 [ 4054.290230] gpio_keys_irq_timer+0x4c/0x78 [ 4054.290243] __hrtimer_run_queues+0x1a4/0x438 [ 4054.290257] hrtimer_interrupt+0xe4/0x240 [ 4054.290269] arch_timer_handler_phys+0x2c/0x44 [ 4054.290283] handle_percpu_devid_irq+0x8c/0x14c [ 4054.290297] handle_irq_desc+0x40/0x58 [ 4054.290307] generic_handle_domain_irq+0x1c/0x28 [ 4054.290316] gic_handle_irq+0x44/0xcc
Considering the gpio_keys_irq_isr() can run in any context, e.g. it can be threaded, it seems there's no point in requesting the timer isr to run in hard irq context.
Relax the hrtimer not to use the hard context.
Fixes: 019002f20cb5 ("Input: gpio-keys - use hrtimer for release timer") Suggested-by: Sebastian Andrzej Siewior bigeasy@linutronix.de Signed-off-by: Fabrice Gasnier fabrice.gasnier@foss.st.com Signed-off-by: Gatien Chevallier gatien.chevallier@foss.st.com Link: https://lore.kernel.org/r/20250528-gpio_keys_preempt_rt-v2-1-3fc55a9c3619@fo... Cc: stable@vger.kernel.org Signed-off-by: Dmitry Torokhov dmitry.torokhov@gmail.com [ adjusted context ] Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/input/keyboard/gpio_keys.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/input/keyboard/gpio_keys.c b/drivers/input/keyboard/gpio_keys.c index c5f4207fddce9..a34b9533d8f18 100644 --- a/drivers/input/keyboard/gpio_keys.c +++ b/drivers/input/keyboard/gpio_keys.c @@ -495,7 +495,7 @@ static irqreturn_t gpio_keys_irq_isr(int irq, void *dev_id) if (bdata->release_delay) hrtimer_start(&bdata->release_timer, ms_to_ktime(bdata->release_delay), - HRTIMER_MODE_REL_HARD); + HRTIMER_MODE_REL); out: spin_unlock_irqrestore(&bdata->lock, flags); return IRQ_HANDLED; @@ -632,7 +632,7 @@ static int gpio_keys_setup_key(struct platform_device *pdev,
bdata->release_delay = button->debounce_interval; hrtimer_init(&bdata->release_timer, - CLOCK_REALTIME, HRTIMER_MODE_REL_HARD); + CLOCK_REALTIME, HRTIMER_MODE_REL); bdata->release_timer.function = gpio_keys_irq_timer;
isr = gpio_keys_irq_isr;