[PATCH v4 5/9] ARM: dts: rockchip: disable arm-global-timer for rk3188
Heiko Stübner
heiko at sntech.de
Mon Jan 23 08:14:22 PST 2017
Am Dienstag, 29. November 2016, 19:14:48 CET schrieb Alexander Kochetkov:
> arm-global-timer can provide clockevents, clocksource and shed_clock. But
> on rk3188 platform it provide only clocksource and shed_clock. clockevents
> from arm-global-timer is not used by kernel because there is another
> clockevent provider with higher rating (smp-twd).
>
> My commit from the series implement clocksource and shed_clock using
> rockchip_timer. But sched clock from rk_timer is not selected by kernel
> due to lower frequency than arm-global-timer, and clocksource from
> rk_timer is not selected by kernel due to lower rating than
> arm-global-timer. And I don't want to increase clocksource rating
> because ratings greater 300 used for high frequency clocksources.
>
> clocksource and shed_clock is quite unstable, because their rate depends
> on cpu frequency. So disable arm-global-timer and use clocksource and
> sched_clock from rockchip_timer.
That commit message is hard to understand in its entirety, but this last
paragraph is essentially enough to describe the problem. So maybe you could
shorten that somehow.
Heiko
> Signed-off-by: Alexander Kochetkov <al.kochet at gmail.com>
> ---
> arch/arm/boot/dts/rk3188.dtsi | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/arch/arm/boot/dts/rk3188.dtsi b/arch/arm/boot/dts/rk3188.dtsi
> index 0dc52fe..44da3d42 100644
> --- a/arch/arm/boot/dts/rk3188.dtsi
> +++ b/arch/arm/boot/dts/rk3188.dtsi
> @@ -546,6 +546,7 @@
>
> &global_timer {
> interrupts = <GIC_PPI 11 0xf04>;
> + status = "disabled";
> };
>
> &local_timer {
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