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From:   Brad Larson <brad@pensando.io>
Date:   Thu, 4 Nov 2021 15:53:13 -0700
Message-ID: <CAK9rFnx7DgS3TYMmu5NBacV_6WC_UwJ=u7n3e_fGd0RpEcg3kA@mail.gmail.com>
Subject: Re: [PATCH v3 11/11] arm64: dts: Add Pensando Elba SoC support
To:     Mark Rutland <mark.rutland@arm.com>
Cc:     Linux ARM <linux-arm-kernel@lists.infradead.org>,
        Arnd Bergmann <arnd@arndb.de>,
        Linus Walleij <linus.walleij@linaro.org>,
        Bartosz Golaszewski <bgolaszewski@baylibre.com>,
        Mark Brown <broonie@kernel.org>,
        Serge Semin <fancer.lancer@gmail.com>,
        Adrian Hunter <adrian.hunter@intel.com>,
        Ulf Hansson <ulf.hansson@linaro.org>,
        Olof Johansson <olof@lixom.net>,
        "open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>,
        linux-spi <linux-spi@vger.kernel.org>,
        linux-mmc <linux-mmc@vger.kernel.org>,
        "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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Hi Mark,

On Mon, Oct 25, 2021 at 2:17 AM Mark Rutland <mark.rutland@arm.com> wrote:
>
> Hi,
>
> On Sun, Oct 24, 2021 at 06:51:56PM -0700, Brad Larson wrote:
> > Add Pensando common and Elba SoC specific device nodes
> >
> > Signed-off-by: Brad Larson <brad@pensando.io>
>
> [...]
>
> > +     timer {
> > +             compatible = "arm,armv8-timer";
> > +             interrupts = <GIC_PPI 13 (GIC_CPU_MASK_SIMPLE(1) |
> > +                                     IRQ_TYPE_LEVEL_LOW)>,
> > +                          <GIC_PPI 14 (GIC_CPU_MASK_SIMPLE(1) |
> > +                                     IRQ_TYPE_LEVEL_LOW)>,
> > +                          <GIC_PPI 11 (GIC_CPU_MASK_SIMPLE(1) |
> > +                                     IRQ_TYPE_LEVEL_LOW)>,
> > +                          <GIC_PPI 10 (GIC_CPU_MASK_SIMPLE(1) |
> > +                                     IRQ_TYPE_LEVEL_LOW)>;
> > +     };
>
> The GIC_CPU_MASK_SIMPLE() stuff is meant for GICv2, but as below you
> have GICv3, where this is not valid, so this should go.
>
> Also, beware that GIC_CPU_MASK_SIMPLE(1) means a single CPU, which
> doesn't mak sense for the 16 CPUs you have.
>

Thanks for pointing this out.  Elba SoC is a GICv3 implementation and looking
at other device tree files we should be using this:

        timer {
                compatible = "arm,armv8-timer";
                interrupts = <GIC_PPI 13 (GIC_CPU_MASK_SIMPLE(16) |
                                        IRQ_TYPE_LEVEL_LOW)>,
                             <GIC_PPI 14 (GIC_CPU_MASK_SIMPLE(16) |
                                        IRQ_TYPE_LEVEL_LOW)>,
                             <GIC_PPI 11 (GIC_CPU_MASK_SIMPLE(16) |
                                        IRQ_TYPE_LEVEL_LOW)>,
                             <GIC_PPI 10 (GIC_CPU_MASK_SIMPLE(16) |
                                        IRQ_TYPE_LEVEL_LOW)>;
        };

> > +             gic: interrupt-controller@800000 {
> > +                     compatible = "arm,gic-v3";
> > +                     #interrupt-cells = <3>;
> > +                     #address-cells = <2>;
> > +                     #size-cells = <2>;
> > +                     ranges;
> > +                     interrupt-controller;
> > +                     reg = <0x0 0x800000 0x0 0x200000>,      /* GICD */
> > +                           <0x0 0xa00000 0x0 0x200000>;      /* GICR */
> > +                     interrupts = <GIC_PPI 9 IRQ_TYPE_LEVEL_HIGH>;
> > +
> > +                     gic_its: msi-controller@820000 {
> > +                             compatible = "arm,gic-v3-its";
> > +                             msi-controller;
> > +                             #msi-cells = <1>;
> > +                             reg = <0x0 0x820000 0x0 0x10000>;
> > +                             socionext,synquacer-pre-its =
> > +                                                     <0xc00000 0x1000000>;
> > +                     };
> > +             };
>
> Is there any shared lineage with Synquacer? The commit message didn't
> describe this quirk.

There is no shared lineage with Synqacer.  We are solving the same issue
with the same mechanism.  I'll add a comment to this DTS node.

Thanks,
Brad