Re: [PATCH v2 6/7] clocksource: mips-gic-timer: Refine rating computation
From: Jiaxun Yang
Date: Fri Jun 21 2024 - 07:18:36 EST
在2024年6月12日六月 上午9:54,Jiaxun Yang写道:
> It is a good clocksource which usually go as fast as CPU core
> and have a low access latency, so raise the base of rating
> from Good to desired when we know that it has a stable frequency.
>
> Increase frequency addend dividend to 10000000 (10MHz) to
> reasonably accommodate multi GHz level clock, also cap rating
> within current level.
>
> Signed-off-by: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx>
Hi Daniel,
Can I get a Review or Ack for this series? As it's mainly clocksource related.
Thanks.
- Jiaxun
> ---
> v2: Fix number of zeros for 10 MHz
> ---
> drivers/clocksource/mips-gic-timer.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/clocksource/mips-gic-timer.c
> b/drivers/clocksource/mips-gic-timer.c
> index b3ae38f36720..7a03d94c028a 100644
> --- a/drivers/clocksource/mips-gic-timer.c
> +++ b/drivers/clocksource/mips-gic-timer.c
> @@ -197,7 +197,11 @@ static int __init __gic_clocksource_init(void)
> gic_clocksource.mask = CLOCKSOURCE_MASK(count_width);
>
> /* Calculate a somewhat reasonable rating value. */
> - gic_clocksource.rating = 200 + gic_frequency / 10000000;
> + if (mips_cm_revision() >= CM_REV_CM3 || !IS_ENABLED(CONFIG_CPU_FREQ))
> + gic_clocksource.rating = 300; /* Good when frequecy is stable */
> + else
> + gic_clocksource.rating = 200;
> + gic_clocksource.rating += clamp(gic_frequency / 10000000, 0, 99);
>
> ret = clocksource_register_hz(&gic_clocksource, gic_frequency);
> if (ret < 0)
>
> --
> 2.43.0
--
- Jiaxun