[PATCH v2 1/2] cyclic: Fix rollover every 72 min on 32 bits platforms

[Stefan Roese]

On 14.01.25 14:28, Patrice Chotard wrote:
> On 32 bits platforms, timer_get_us() returns an unsigned long which
> is a 32 bits. timer_get_us() wraps around every 72 minutes
> (2 ^ 32 / 1000000 =~ 4295 sec =~ 72 min).
> 
> So the test "if time_after_eq64(now, cyclic->next_call)" is no more
> true when cyclic->next_call becomes above 32 bits max value (4294967295).
> 
> At this point after 72 min, no more cyclic function are
> executed included watchdog one.
> 
> Instead of using timer_get_us(), use get_timer_us() which returns a
> uint64_t, this allows a rollover every 584942 years.
> 
> Signed-off-by: Patrice Chotard <patrice.chotard at foss.st.com>
> 
> ---
> 
> Changes in v2:
>        _ Replace remaining timer_get_us() by get_timer_us(0)

Reviewed-by: Stefan Roese <sr at denx.de>

Thanks,
Stefan

> 
>   common/cyclic.c | 6 +++---
>   1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/common/cyclic.c b/common/cyclic.c
> index 196797fd61e..fad071a39c6 100644
> --- a/common/cyclic.c
> +++ b/common/cyclic.c
> @@ -36,7 +36,7 @@ void cyclic_register(struct cyclic_info *cyclic, cyclic_func_t func,
>   	cyclic->func = func;
>   	cyclic->name = name;
>   	cyclic->delay_us = delay_us;
> -	cyclic->start_time_us = timer_get_us();
> +	cyclic->start_time_us = get_timer_us(0);
>   	hlist_add_head(&cyclic->list, cyclic_get_list());
>   }
>   
> @@ -61,13 +61,13 @@ static void cyclic_run(void)
>   		 * Check if this cyclic function needs to get called, e.g.
>   		 * do not call the cyclic func too often
>   		 */
> -		now = timer_get_us();
> +		now = get_timer_us(0);
>   		if (time_after_eq64(now, cyclic->next_call)) {
>   			/* Call cyclic function and account it's cpu-time */
>   			cyclic->next_call = now + cyclic->delay_us;
>   			cyclic->func(cyclic);
>   			cyclic->run_cnt++;
> -			cpu_time = timer_get_us() - now;
> +			cpu_time = get_timer_us(0) - now;
>   			cyclic->cpu_time_us += cpu_time;
>   
>   			/* Check if cpu-time exceeds max allowed time */

Viele Grüße,
Stefan Roese

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