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Date:   Thu, 14 Dec 2023 10:43:28 +0530
From:   Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
To:     Sherry Sun <sherry.sun@nxp.com>
Cc:     hongxing.zhu@nxp.com, l.stach@pengutronix.de,
        lpieralisi@kernel.org, kw@linux.com, robh@kernel.org,
        bhelgaas@google.com, krzysztof.kozlowski+dt@linaro.org,
        conor+dt@kernel.org, shawnguo@kernel.org, s.hauer@pengutronix.de,
        kernel@pengutronix.de, festevam@gmail.com, linux-imx@nxp.com,
        linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH V2 0/4] PCI: imx6: Add pci host wakeup support
Message-ID: <20231214051328.GD2938@thinkpad>
References: <20231213092850.1706042-1-sherry.sun@nxp.com>
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On Wed, Dec 13, 2023 at 05:28:46PM +0800, Sherry Sun wrote:
> Add pci host wakeup feature for imx platforms. The host wake pin is a
> standard feature in the PCIe bus specification, so we can add this
> property under PCI dts node to support the host gpio wakeup feature.
> 
> Example of configuring the corresponding dts property under the PCI node:
>     wake-gpios = <&gpio5 21 GPIO_ACTIVE_LOW>;
> 

As you mentioned, WAKE# is a standard sideband signal defined in the PCI spec.
So the support for handling it has to be in the PCI core layer, not in the
host controller drivers.

There is already a series floating to add support for WAKE# in PCI core. Please
take a look:

https://lore.kernel.org/linux-pci/20230208111645.3863534-1-mmaddireddy@nvidia.com/

- Mani

> ---
> changes in V2:
> 1. Rename host-wake-gpio property to wake-gpios.
> 2. Improve the wake-gpios property description in the dt-binding doc to avoid
> confusion.
> 3. Remove unnecessary debugging info in host_wake_irq_handler().
> 4. Remove unnecessary imx6_pcie->host_wake_irq = -1 resetting in error paths.
> 5. Use dev_err_probe() to simplify error path code.
> ---
> 
> Sherry Sun (4):
>   PCI: imx6: Add pci host wakeup support on imx platforms.
>   dt-bindings: imx6q-pcie: Add wake-gpios property
>   arm64: dts: imx8mp-evk: add wake-gpios property for pci bus
>   arm64: dts: imx8mq-evk: add wake-gpios property for pci bus
> 
>  .../bindings/pci/fsl,imx6q-pcie.yaml          |  6 ++
>  arch/arm64/boot/dts/freescale/imx8mp-evk.dts  |  2 +
>  arch/arm64/boot/dts/freescale/imx8mq-evk.dts  |  2 +
>  drivers/pci/controller/dwc/pci-imx6.c         | 60 +++++++++++++++++++
>  4 files changed, 70 insertions(+)
> 
> -- 
> 2.34.1
> 
> 

-- 
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