RE: [PATCH v2 14/17] arm64: dts: realtek: Add EL2 virtual timer interrupt

["Yu-Chun Lin [林祐君]" <eleanor.lin@realtek.com>]

> On Fri, 15 May 2026 00:18:03 +0100,
> sashiko-bot@kernel.org wrote:
> >
> > Thank you for your contribution! Sashiko AI review found 1 potential issue(s)
> to consider:
> > - [High] Incomplete implementation: missing update for Realtek Kent SoC
> family which specifies an incorrect EL2 virtual timer interrupt.
> > --
> >
> > commit 3b73638950a28ecc324e1c28fa4fb9fcb13d5567
> > Author: Marc Zyngier <maz@kernel.org>
> >
> > arm64: dts: realtek: Add EL2 virtual timer interrupt
> >
> > This commit adds the missing EL2 virtual timer interrupt to
> > ARMv8.2-based Realtek SoCs. It updates rtd16xx.dtsi by adding the
> > fifth timer interrupt with GIC_PPI 12.
> >
> > > diff --git a/arch/arm64/boot/dts/realtek/rtd16xx.dtsi
> > > b/arch/arm64/boot/dts/realtek/rtd16xx.dtsi
> > > index 3a7f6e35b7f74..43b13d133c324 100644
> > > --- a/arch/arm64/boot/dts/realtek/rtd16xx.dtsi
> > > +++ b/arch/arm64/boot/dts/realtek/rtd16xx.dtsi
> > > @@ -105,7 +105,8 @@ timer {
> > >             interrupts = <GIC_PPI 13 IRQ_TYPE_LEVEL_LOW>,
> > >                          <GIC_PPI 14 IRQ_TYPE_LEVEL_LOW>,
> > >                          <GIC_PPI 11 IRQ_TYPE_LEVEL_LOW>,
> > > -                        <GIC_PPI 10 IRQ_TYPE_LEVEL_LOW>;
> > > +                        <GIC_PPI 10 IRQ_TYPE_LEVEL_LOW>,
> > > +                        <GIC_PPI 12 IRQ_TYPE_LEVEL_LOW>;
> > >     };
> >
> > Does this update miss another Realtek ARMv8.2+ SoC file?
> >
> > Looking at arch/arm64/boot/dts/realtek/kent.dtsi (used by RTD1501,
> > RTD1861, and RTD1920), the fifth timer interrupt is currently defined
> > as <GIC_PPI 9 IRQ_TYPE_LEVEL_HIGH>.
> >
> > PPI 9 is the GIC vCPU maintenance interrupt, rather than the EL2
> > virtual timer interrupt which should be PPI 12:
> >
> > arch/arm64/boot/dts/realtek/kent.dtsi:
> >       timer {
> >               compatible = "arm,armv8-timer";
> >               interrupts = <GIC_PPI 13 IRQ_TYPE_LEVEL_LOW>,
> >                            <GIC_PPI 14 IRQ_TYPE_LEVEL_LOW>,
> >                            <GIC_PPI 11 IRQ_TYPE_LEVEL_LOW>,
> >                            <GIC_PPI 10 IRQ_TYPE_LEVEL_LOW>,
> >                            <GIC_PPI  9 IRQ_TYPE_LEVEL_HIGH>;
> >       };
> >
> > Another patch in this series (clocksource/drivers/arm_arch_timer:
> > Default to EL2 virtual timer when running VHE) changes the driver to
> > use the EL2 virtual timer by default on VHE systems.
> >
> > If the kernel uses the EL2 virtual timer on these Realtek SoCs, could
> > it request the wrong interrupt (PPI 9 instead of PPI 12), causing
> > timer interrupts to not be delivered and resulting in a boot hang regression?
> 
> That's definitely odd, as PPI9 is present in two interrupt specifiers (timer and
> GIC). Obviously, that's not possible.
> 
> I'll add a tentative fix for that in the next round. Maybe Andreas or Yu-Chun
> can check in the meantime?
> 
>         M.
> 
> --
> Jazz isn't dead. It just smells funny.

Hi Marc,

I checked with my colleagues and confirmed that this is indeed a typo in kent.dtsi.
The fifth interrupt entry should be corrected to:

<GIC_PPI 12 IRQ_TYPE_LEVEL_LOW>;

It would be great if you could include the fix in your next round. Otherwise, just
let me know and I'll send a separate patch.

Thanks,
Yu-Chun