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From: Frank Li <Frank.li@nxp.com>
To: Richard Zhu <hongxing.zhu@nxp.com>
Cc: l.stach@pengutronix.de, lpieralisi@kernel.org, kw@linux.com,
	manivannan.sadhasivam@linaro.org, robh@kernel.org,
	bhelgaas@google.com, shawnguo@kernel.org, s.hauer@pengutronix.de,
	kernel@pengutronix.de, festevam@gmail.com,
	linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	imx@lists.linux.dev, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v1] PCI: imx6: Align EP link start behavior with documentation
Date: Fri, 6 Jun 2025 11:30:02 -0400	[thread overview]
Message-ID: <aEMJeovM0G/+WZo7@lizhi-Precision-Tower-5810> (raw)
In-Reply-To: <20250606075729.3855815-1-hongxing.zhu@nxp.com>

On Fri, Jun 06, 2025 at 03:57:29PM +0800, Richard Zhu wrote:
> According to PCI/endpoint/pci-endpoint-cfs.rst, the endpoint (EP) should
> only link up after `echo 1 > start` is executed.
>
> To match the documented behavior, do not start the link automatically
> when adding the EP controller. Ensure the LTSSM_EN bit is not asserted
> to 1'b1 by default.

Reviewed-by: Frank Li <Frank.Li@nxp.com>

>
> Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
> ---
>  drivers/pci/controller/dwc/pci-imx6.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
> index 5f267dd261b5..69825e47d2d4 100644
> --- a/drivers/pci/controller/dwc/pci-imx6.c
> +++ b/drivers/pci/controller/dwc/pci-imx6.c
> @@ -1337,6 +1337,10 @@ static int imx_add_pcie_ep(struct imx_pcie *imx_pcie,
>  	struct device *dev = pci->dev;
>
>  	imx_pcie_host_init(pp);
> +
> +	/* Make sure that PCIe LTSSM is cleared */
> +	imx_pcie_ltssm_disable(dev);
> +
>  	ep = &pci->ep;
>  	ep->ops = &pcie_ep_ops;
>
> @@ -1360,9 +1364,6 @@ static int imx_add_pcie_ep(struct imx_pcie *imx_pcie,
>
>  	pci_epc_init_notify(ep->epc);
>
> -	/* Start LTSSM. */
> -	imx_pcie_ltssm_enable(dev);
> -
>  	return 0;
>  }
>
> --
> 2.37.1
>


      reply	other threads:[~2025-06-06 15:32 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-06-06  7:57 [PATCH v1] PCI: imx6: Align EP link start behavior with documentation Richard Zhu
2025-06-06 15:30 ` Frank Li [this message]

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