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Date:   Mon, 01 Apr 2019 03:02:17 +0100
Message-ID: <86r2am5vpy.wl-marc.zyngier@arm.com>
From:   Marc Zyngier <marc.zyngier@arm.com>
To:     Hanna Hawa <hhhawa@amazon.com>
Cc:     <tsahee@annapurnalabs.com>, <antoine.tenart@bootlin.com>,
        <linux@armlinux.org.uk>, <catalin.marinas@arm.com>,
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        <tglx@linutronix.de>, <jason@lakedaemon.net>, <ronenk@amazon.com>,
        <dwmw@amazon.co.uk>, <vaerov@amazon.com>, <zeev@amazon.com>,
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        <hanochu@amazon.com>, <barakw@amazon.com>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>, <linux-acpi@vger.kernel.org>,
        Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Subject: Re: [PATCH 0/7] al-msi: Rename driver and add support for ACPI
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References: <1554035655-11352-1-git-send-email-hhhawa@amazon.com>
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On Sun, 31 Mar 2019 13:34:08 +0100,
Hanna Hawa <hhhawa@amazon.com> wrote:
> 
> This series includes three major changes:
> 1. IOMMU DMA mapping MSI message fix.
> 2. Re-name the AL-MSIx driver to new name convention.
> 3. Add ACPI support for the driver.
> 
> Alpine is the name of the SoC family, while AL stands for Annapurna
> Labs. Rename to the latter since the driver will appear in other SoC
> families other than Alpine.
> 
> The AL-MSIx controller is not standard, is not included in the UEFI
> specification, and will not be added. The driver ACPI binding is
> performed when the following conditions are true:
> - OEM ID is AMAZON
> - MADT table type is 0x80 (part of the OEM reserved range).

[+Lorenzo, as the arm64 ACPI maintainer]

So you're happy to explicitly violate the letter of the specification?
That's not really going to fly. We've pushed back on such things in
the past (MBIGEN, XGene MSI controller), and I don't see any
compelling reason to change our tune.

> GICv2m driver is called from context of parent interrupt controller,
> which ensures that the parent interrupt domain exists and holds valid
> information. As calling AL-MSIx driver from GICv3 driver would not make
> sense, a new API was added, to get the GSI IRQ domain that was registered
> by GICv3 driver in the ACPI framework.

What does this mean? Either your system has a GICv2m or it has a
GICv3. Please explain what this is all about.

Thanks,

	M.

-- 
Jazz is not dead, it just smell funny.