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From: Richard Zhu <hongxing.zhu@nxp.com>
To: frank.li@nxp.com, 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
Cc: linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	imx@lists.linux.dev, linux-kernel@vger.kernel.org,
	Richard Zhu <hongxing.zhu@nxp.com>
Subject: [PATCH v1] PCI: imx6: Align EP link start behavior with documentation
Date: Fri,  6 Jun 2025 15:57:29 +0800	[thread overview]
Message-ID: <20250606075729.3855815-1-hongxing.zhu@nxp.com> (raw)

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.

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  8:01 UTC|newest]

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

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