Re: [PATCH v4 1/4] clocksource: stm32: convert driver to timer_of

[Benjamin Gaignard]

2017-10-17 19:09 GMT+02:00 Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>:
> On 02/10/2017 17:51, Benjamin Gaignard wrote:
>> Convert driver to use timer_of helpers. This allow to remove
>> custom proprietary structure.
>>
>> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@xxxxxxxxxx>
>> ---
>
> [ ... ]
>
>> -     clockevents_config_and_register(&data->evtdev,
>> -                                     DIV_ROUND_CLOSEST(rate, prescaler),
>> -                                     0x1, max_delta);
>> -
>> -     ret = request_irq(irq, stm32_clock_event_handler, IRQF_TIMER,
>> -                     "stm32 clockevent", data);
>> -     if (ret) {
>> -             pr_err("%pOF: failed to request irq.\n", np);
>> -             goto err_get_irq;
>> -     }
>> +     clockevents_config_and_register(&to->clkevt,
>> +                                     timer_of_period(to), 0x60, max_delta);
>
>
> Why 0x1 -> 0x60 ?

Because if the min delta is too small it could generate too much interrupts
and the system will not be able to catch all of them.

>
> --
>  <http://www.linaro.org/> Linaro.org â Open source software for ARM SoCs
>
> Follow Linaro:  <http://www.facebook.com/pages/Linaro> Facebook |
> <http://twitter.com/#!/linaroorg> Twitter |
> <http://www.linaro.org/linaro-blog/> Blog
>