Re: [PATCH] pinctrl: stm32: fix the unit of the hwspinlock timeout

[Antonio Borneo]

On Wed, 2026-08-05 at 11:28 +0800, Ju Nan wrote:
> 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 the driver asks for a 1 second timeout where the comment next to the
> macro says it wants 1 millisecond.
> 
> 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.
> 
> Pass the value the comment always described. The core retries every
> HWSPINLOCK_RETRY_DELAY_US (100 us), so the semaphore is still polled ten
> times before giving up, which is far longer than any plausible hold time
> on the coprocessor side. A timeout is reported with dev_err() and fails
> the pin configuration or the interrupt allocation, so shortening it
> degrades gracefully.
> 
> Signed-off-by: Ju Nan <junan76@xxxxxxx>

Please add
Fixes: 290a9f937e5a ("pinctrl: stm32: use the hwspin_lock_timeout_in_atomic() API")

> ---
>  drivers/pinctrl/stm32/pinctrl-stm32.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/pinctrl/stm32/pinctrl-stm32.c b/drivers/pinctrl/stm32/pinctrl-stm32.c
> index 6a99708a5..dbc9143ec 100644
> --- a/drivers/pinctrl/stm32/pinctrl-stm32.c
> +++ b/drivers/pinctrl/stm32/pinctrl-stm32.c
> @@ -87,7 +87,7 @@
>  #define gpio_range_to_bank(chip) \
>                 container_of(chip, struct stm32_gpio_bank, range)
>  
> -#define HWSPNLCK_TIMEOUT       1000 /* usec */
> +#define HWSPNLCK_TIMEOUT       1 /* msec */

Please change the macro name as HWSPNLCK_TIMEOUT_MS to keep track of the time units

>  
>  static const char * const stm32_gpio_functions[] = {
>         "gpio", "af0", "af1",

Thanks!
Antonio