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

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
commit d31fbbade4