Messages in this thread Patch in this message | | | Date | Fri, 25 Jun 2021 12:31:17 +0100 | From | Paul Cercueil <> | Subject | Re: [PATCH v3 4/4] MIPS: CI20: Add second percpu timer for SMP. |
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Hi Zhou,
Le jeu., juin 24 2021 at 23:06:29 +0800, 周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com> a écrit : > 1.Add a new TCU channel as the percpu timer of core1, this is to > prepare for the subsequent SMP support. The newly added channel > will not adversely affect the current single-core state. > 2.Adjust the position of TCU node to make it consistent with the > order in jz4780.dtsi file.
That's a bit superfluous, the order matters when adding new nodes, but once they are added, moving them around only cause annoyance.
> > Signed-off-by: 周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com> > --- > > Notes: > v2: > New patch. > > v2->v3: > No change. > > arch/mips/boot/dts/ingenic/ci20.dts | 21 +++++++++++---------- > 1 file changed, 11 insertions(+), 10 deletions(-) > > diff --git a/arch/mips/boot/dts/ingenic/ci20.dts > b/arch/mips/boot/dts/ingenic/ci20.dts > index 8877c62..70005cc 100644 > --- a/arch/mips/boot/dts/ingenic/ci20.dts > +++ b/arch/mips/boot/dts/ingenic/ci20.dts > @@ -118,6 +118,17 @@ > assigned-clock-rates = <48000000>; > }; > > +&tcu { > + /* > + * 750 kHz for the system timers and 3 MHz for the clocksources, > + * use channel #0 and #1 for the per cpu system timers, and use > + * channel #2 for the clocksource. > + */ > + assigned-clocks = <&tcu TCU_CLK_TIMER0>, <&tcu TCU_CLK_TIMER1>, > + <&tcu TCU_CLK_TIMER2>, <&tcu TCU_CLK_OST>; > + assigned-clock-rates = <750000>, <750000>, <3000000>, <3000000>;
Ideally you'd set TIMER1 to 3 MHz and TIMER2 to 750 kHz, otherwise it kind of breaks support for older kernels (they would still boot, but with a very slow clocksource). So in the new DTS you could use the timer0 clock for CPU #0, timer1 for the clocksource, and timer2+ for cpus > 0.
Cheers, -Paul
> +}; > + > &mmc0 { > status = "okay"; > > @@ -522,13 +533,3 @@ > bias-disable; > }; > }; > - > -&tcu { > - /* > - * 750 kHz for the system timer and 3 MHz for the clocksource, > - * use channel #0 for the system timer, #1 for the clocksource. > - */ > - assigned-clocks = <&tcu TCU_CLK_TIMER0>, <&tcu TCU_CLK_TIMER1>, > - <&tcu TCU_CLK_OST>; > - assigned-clock-rates = <750000>, <3000000>, <3000000>; > -}; > -- > 2.7.4 >
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