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Date:   Mon, 4 Jan 2021 06:55:44 -0600
From:   Nishanth Menon <nm@ti.com>
To:     Kishon Vijay Abraham I <kishon@ti.com>
CC:     Rob Herring <robh+dt@kernel.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v3 1/6] arm64: dts: ti: k3-j721e-main: Fix supported max
 outbound regions
Message-ID: <20210104125544.arluqus2xbqwacez@curler>
References: <20210104122232.24071-1-kishon@ti.com>
 <20210104122232.24071-2-kishon@ti.com>
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On 17:52-20210104, Kishon Vijay Abraham I wrote:
> Cadence IP in J721E supports a maximum of 32 outbound regions. However
> commit 4e5833884f66 ("arm64: dts: ti: k3-j721e-main: Add PCIe device
> tree nodes") incorrectly added this as 16 outbound regions. Now that
> "cdns,max-outbound-regions" is an optional property with default value
> as 32, remove "cdns,max-outbound-regions" from endpoint DT node.
> 
> Fixes: 4e5833884f66 ("arm64: dts: ti: k3-j721e-main: Add PCIe device tree nodes")

^^ Is this a backward compatible fixup. If I were to apply this on
v5.10, wont we have a broken PCIe functionality? Drop the fixes if this
is not backward compatible fixup (unless ofcourse the driver fixup is
backported all the way back as well - I am assuming will be done in a
manner to preserve compatibility with older dtb?)

On master right now:
$ git grep "cdns,max-outbound-regions" .
Documentation/devicetree/bindings/pci/cdns,cdns-pcie-ep.yaml:                cdns,max-outbound-regions = <16>;
Documentation/devicetree/bindings/pci/cdns-pcie-ep.yaml:  cdns,max-outbound-regions:
Documentation/devicetree/bindings/pci/cdns-pcie-host.yaml:  cdns,max-outbound-regions:
arch/arm64/boot/dts/ti/k3-j721e-main.dtsi:              cdns,max-outbound-regions = <16>;
arch/arm64/boot/dts/ti/k3-j721e-main.dtsi:              cdns,max-outbound-regions = <16>;
arch/arm64/boot/dts/ti/k3-j721e-main.dtsi:              cdns,max-outbound-regions = <16>;
arch/arm64/boot/dts/ti/k3-j721e-main.dtsi:              cdns,max-outbound-regions = <16>;
drivers/pci/controller/cadence/pcie-cadence-ep.c:       of_property_read_u32(np, "cdns,max-outbound-regions", &ep->max_regions);


> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
> ---
>  arch/arm64/boot/dts/ti/k3-j721e-main.dtsi | 4 ----
>  1 file changed, 4 deletions(-)
> 

-- 
Regards,
Nishanth Menon
Key (0xDDB5849D1736249D) / Fingerprint: F8A2 8693 54EB 8232 17A3  1A34 DDB5 849D 1736 249D