Re: [PATCH v8 04/16] dt-bindings: imx6q-pcie: Add linux,pci-domain as required for iMX8MQ

From: Rob Herring <robh@kernel.org>
To: Frank Li <Frank.Li@nxp.com>
Cc: krzysztof.kozlowski@linaro.org, bhelgaas@google.com,
	conor+dt@kernel.org, devicetree@vger.kernel.org,
	festevam@gmail.com, helgaas@kernel.org, hongxing.zhu@nxp.com,
	imx@lists.linux.dev, kernel@pengutronix.de,
	krzysztof.kozlowski+dt@linaro.org, kw@linux.com,
	l.stach@pengutronix.de, linux-arm-kernel@lists.infradead.org,
	linux-imx@nxp.com, linux-kernel@vger.kernel.org,
	linux-pci@vger.kernel.org, lpieralisi@kernel.org,
	manivannan.sadhasivam@linaro.org, s.hauer@pengutronix.de,
	shawnguo@kernel.org
Subject: Re: [PATCH v8 04/16] dt-bindings: imx6q-pcie: Add linux,pci-domain as required for iMX8MQ
Date: Tue, 9 Jan 2024 12:24:20 -0600	[thread overview]
Message-ID: <20240109182420.GA2896319-robh@kernel.org> (raw)
In-Reply-To: <20240108232145.2116455-5-Frank.Li@nxp.com>

On Mon, Jan 08, 2024 at 06:21:33PM -0500, Frank Li wrote:
> iMX8MQ have two pci controllers. Adds "linux,pci-domain" as required
> property for iMX8MQ to indicate pci controller index.
> 
> This adjustment paves the way for eliminating the hardcoded check on the
> base register for acquiring the controller_id.
> 
> 	...
> 	if (dbi_base->start == IMX8MQ_PCIE2_BASE_ADDR)
> 		imx6_pcie->controller_id = 1;
> 	...
> 
> The controller_id is crucial and utilized for certain register bit
> positions. It must align precisely with the controller index in the SoC.
> An auto-incremented ID don't fit this case. The DTS or fuse configurations
> may deactivate specific PCI controllers.
> 
> Signed-off-by: Frank Li <Frank.Li@nxp.com>
> ---
> 
> Notes:
>     Keep current to avoid DTB_CHECK warning. After these patch merged. Will add
>     linux,pci-domain in all dts file. So dt-binding can remove condition check
>     by soc.

Please don't. No need to make required everywhere. Besides not needed, 
it is an ABI break.

Rob