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Date: Wed, 15 Oct 2025 09:38:11 +0200
From: Lorenzo Pieralisi <lpieralisi@kernel.org>
To: Bjorn Helgaas <helgaas@kernel.org>
Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	devicetree@vger.kernel.org, linux-pci@vger.kernel.org,
	Sascha Bischoff <sascha.bischoff@arm.com>,
	Rob Herring <robh@kernel.org>, Marc Zyngier <maz@kernel.org>,
	Scott Branden <sbranden@broadcom.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Bjorn Helgaas <bhelgaas@google.com>, Ray Jui <rjui@broadcom.com>,
	Frank Li <Frank.Li@nxp.com>,
	Manivannan Sadhasivam <mani@kernel.org>,
	Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= <kwilczynski@kernel.org>
Subject: Re: [PATCH v2 1/4] of/irq: Add msi-parent check to of_msi_xlate()
Message-ID: <aO9PY2Ze2ISkNP1Z@lpieralisi>
References: <20251014095845.1310624-2-lpieralisi@kernel.org>
 <20251014222940.GA913235@bhelgaas>
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In-Reply-To: <20251014222940.GA913235@bhelgaas>

On Tue, Oct 14, 2025 at 05:29:40PM -0500, Bjorn Helgaas wrote:
> On Tue, Oct 14, 2025 at 11:58:42AM +0200, Lorenzo Pieralisi wrote:
> > In some legacy platforms the MSI controller for a PCI host bridge is
> > identified by an msi-parent property whose phandle points at an MSI
> > controller node with no #msi-cells property, that implicitly means
> 
> Looks like you intended to continue the sentence here?

Sigh. "that implicitly means #msi-cells == 0", the `#` caused this.

Apologies.

Lorenzo

> > For such platforms, mapping a device ID and retrieving the MSI controller
> > node becomes simply a matter of checking whether in the device hierarchy
> > there is an msi-parent property pointing at an MSI controller node with
> > such characteristics.
> > 
> > Add a helper function to of_msi_xlate() to check the msi-parent property in
> > addition to msi-map and retrieve the MSI controller node (with a 1:1 ID
> > deviceID-IN<->deviceID-OUT  mapping) to provide support for deviceID
> > mapping and MSI controller node retrieval for such platforms.