Date:   Wed, 01 Mar 2023 16:24:07 +0000
Message-ID: <86k000l9so.wl-maz@kernel.org>
From:   Marc Zyngier <maz@kernel.org>
To:     Robin Murphy <robin.murphy@arm.com>
Cc:     Tim Harvey <tharvey@gateworks.com>,
        Ulf Hansson <ulf.hansson@linaro.org>,
        Al Cooper <alcooperx@gmail.com>,
        Adrian Hunter <adrian.hunter@intel.com>, tglx@linutronix.de,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH] irqchip/gic-v3: Claim iomem resources
In-Reply-To: <410c8561-a7e3-6a3f-b634-08adaa806111@arm.com>
References: <c534c2a458a3bf94ccdae8abc6edc3d45a689c30.1649777295.git.robin.murphy@arm.com>
        <CAJ+vNU3+rz50MRQQsz39Jfbspy2ig9tqzb_yg1RFooxGutCM+g@mail.gmail.com>
        <86lekhl6i6.wl-maz@kernel.org>
        <410c8561-a7e3-6a3f-b634-08adaa806111@arm.com>
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On Wed, 01 Mar 2023 16:12:58 +0000,
Robin Murphy <robin.murphy@arm.com> wrote:
> 
> On 2023-02-28 23:22, Marc Zyngier wrote:
> > On Tue, 28 Feb 2023 23:11:15 +0000,
> > Tim Harvey <tharvey@gateworks.com> wrote:
> >> 
> >> I have bisected a kernel issue where octeontx (CN803x) will hang on
> >> reboot caused by commit c0db06fd0993 ("mmc: core: Disable card detect
> >> during shutdown"). This commit made it into 5.16 and stable kernels.
> >> I've found that the patch here which is commit 2b2cd74a06c3 resolves
> >> this hang but I'm not entirely clear why.
> >> 
> >> Does anyone have a good explanation of why the hang occurs in the
> >> first place and why this resolves it? I would like to get the proper
> >> fix into the affected stable branches.
> > 
> > Wild guess: the reservation prevents some other driver from probing
> > because the firmware describes overlapping ranges, and that driver is
> > what is causing your above hang.
> 
> Indeed, according to [1], the GIC appears to overlap one of the "PCIe"
> windows of &ecam0, which conveniently appears to be the parent of the
> MMC controller as well.

Huh, quality firmware. So clearly nothing to backport. Just a DT
update to distribute... :-/

	M.

-- 
Without deviation from the norm, progress is not possible.