Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.37 as permitted sender) client-ip=23.128.96.37;
MIME-Version: 1.0
References: <20231002094526.1.Ie8f760213053e3d11592f892b30912dbac6b8b48@changeid>
 <ZRr8r7XMoyDKaitd@FVFF77S0Q05N.cambridge.arm.com> <CAD=FV=UeeL9uycVeKpOm+eDm3xHrOnKi2frt6a1qFG1HX9yEUg@mail.gmail.com>
 <ZRwJKBZaYwF1rrur@FVFF77S0Q05N> <CAD=FV=WASz1uvTgwsu3H3cTr3smHk+E_XNUVnjoPpttwv095rQ@mail.gmail.com>
 <ZRxCCZxZWCG0NBur@FVFF77S0Q05N> <CAD=FV=Xk-OMKQPXxU9Z9HOcWwUxxrmLZ4vD0u5ouZRW_zDFDPg@mail.gmail.com>
 <ZR03liCodnTQWs7s@FVFF77S0Q05N> <86jzs2ofqs.wl-maz@kernel.org>
 <CAD=FV=XasZR6dhKBjpbYfby4F1Nu_bsq1m_HP+NpufjsJi0COg@mail.gmail.com>
 <ZR6Pjk_3gpx1K3pF@FVFF77S0Q05N> <864jj4njb7.wl-maz@kernel.org>
In-Reply-To: <864jj4njb7.wl-maz@kernel.org>
From:   Doug Anderson <dianders@chromium.org>
Date:   Fri, 6 Oct 2023 15:17:24 -0700
Message-ID: <CAD=FV=Wdkm6uMMtSL0qWmciaNV33Q-OFw_ttPo3zUzpoguBjsg@mail.gmail.com>
Subject: Re: [PATCH 1/2] arm64: smp: Fix pseudo NMI issues w/ broken Mediatek FW
To:     Marc Zyngier <maz@kernel.org>
Cc:     Mark Rutland <mark.rutland@arm.com>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>,
        Stephen Boyd <swboyd@chromium.org>,
        Valentin Schneider <vschneid@redhat.com>,
        Chen-Yu Tsai <wenst@chromium.org>,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>,
        D Scott Phillips <scott@os.amperecomputing.com>,
        Josh Poimboeuf <jpoimboe@kernel.org>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        Misono Tomohiro <misono.tomohiro@fujitsu.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Sumit Garg <sumit.garg@linaro.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-mediatek@lists.infradead.org
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

Hi,

On Fri, Oct 6, 2023 at 3:20=E2=80=AFAM Marc Zyngier <maz@kernel.org> wrote:
>
> On Thu, 05 Oct 2023 11:27:26 +0100,
> Mark Rutland <mark.rutland@arm.com> wrote:
>
> > 3) Partial fix: make the ARM64_HAS_GIC_PRIO_MASKING cpucap depend on th=
e
> >    absence of a "mediatek,broken-save-restore-fw" property in the DT. I=
 believe
> >    we can check that in early_enable_pseudo_nmi() or can_use_gic_priori=
ties().
> >
> >    That'll avoid potential issues if/when we change the priorities used=
 for
> >    pNMI (which is something I've been looking at).
> >
> > I'm happy with (3) if Marc is.
>
> Definitely worth investigating if you have the bandwidth.

I made an attempt at it. See:

https://lore.kernel.org/20231006151547.1.Ide945748593cffd8ff0feb9ae22b79593=
5b944d6@changeid