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irqchip/stm32mp-exti: Fix the unit of the hwspinlock timeout

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HWSPNLCK_TIMEOUT is passed to hwspin_lock_timeout_in_atomic(), whose
timeout argument is in milliseconds, not microseconds:

  atomic_delay += HWSPINLOCK_RETRY_DELAY_US;
  if (atomic_delay > to * 1000)
          return -ETIMEDOUT;

So stm32mp_exti_set_type() asks for a 1 second timeout where the comment
next to the macro says it wants 1 millisecond. The semaphore is polled
with udelay() from a section that holds chip_data->rlock, a
raw_spinlock_t, so preemption stays disabled for the whole wait on every
configuration, PREEMPT_RT included.

The hwspinlock core documents this explicitly:

  If the mode is HWLOCK_IN_ATOMIC (called from an atomic context) the
  timeout is handled with busy-waiting delays, hence shall not exceed
  few msecs.

Fixes: 5257169ade ("irqchip/stm32-exti: Use the hwspin_lock_timeout_in_atomic() API")
Signed-off-by: Ju Nan <junan76@163.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Radu Rendec <radu@rendec.net>
Reviewed-by: Antonio Borneo <antonio.borneo@foss.st.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260821024756.24927-2-junan76@163.com
This commit is contained in:
Ju Nan 2026-08-21 10:47:57 +08:00 committed by Thomas Gleixner
parent e67091609c
commit d31fbbade4
1 changed files with 2 additions and 2 deletions
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4
drivers/irqchip/irq-stm32mp-exti.c
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@ -22,7 +22,7 @@
#define IRQS_PER_BANK 32
#define HWSPNLCK_TIMEOUT 1000 /* usec */
#define HWSPNLCK_TIMEOUT_MS 1
#define EXTI_EnCIDCFGR(n) (0x180 + (n) * 4)
#define EXTI_HWCFGR1 0x3f0
@ -376,7 +376,7 @@ static int stm32mp_exti_set_type(struct irq_data *d, unsigned int type)
raw_spin_lock(&chip_data->rlock);
if (hwlock) {
err = hwspin_lock_timeout_in_atomic(hwlock, HWSPNLCK_TIMEOUT);
err = hwspin_lock_timeout_in_atomic(hwlock, HWSPNLCK_TIMEOUT_MS);
if (err) {
pr_err("%s can't get hwspinlock (%d)\n", __func__, err);
goto unlock;