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From:   Richard Zhu <hongxing.zhu@nxp.com>
To:     l.stach@pengutronix.de, bhelgaas@google.com,
        lorenzo.pieralisi@arm.com, tharvey@gateworks.com
Cc:     hongxing.zhu@nxp.com, linux-pci@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        kernel@pengutronix.de, linux-imx@nxp.com
Subject: [PATCH v2] PCI: imx6: Support more than Gen2 speed link mode
Date:   Wed, 20 Jul 2022 11:26:16 +0800
Message-Id: <1658287576-26908-1-git-send-email-hongxing.zhu@nxp.com>
Precedence: bulk

Support more than Gen2 speed link mode, since i.MX8MP PCIe supports up to
Gen3 link speed.

Link: https://lore.kernel.org/r/1652866528-13220-2-git-send-email-hongxing.zhu@nxp.com
Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
---
Changes from v1:
- The Supported Link Speeds of the PCI_EXP_LNKCAP should be re-configured too.
- When only Gen1 is enabled, refine the dev_info accordingly.

---
 drivers/pci/controller/dwc/pci-imx6.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index e1ba11dabaa8..b66876f7efe0 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -844,12 +844,12 @@ static int imx6_pcie_start_link(struct dw_pcie *pci)
 	if (ret)
 		goto err_reset_phy;
 
-	if (pci->link_gen == 2) {
-		/* Allow Gen2 mode after the link is up. */
+	if (pci->link_gen > 1) {
+		/* Allow faster modes after the link is up */
 		dw_pcie_dbi_ro_wr_en(pci);
 		tmp = dw_pcie_readl_dbi(pci, offset + PCI_EXP_LNKCAP);
 		tmp &= ~PCI_EXP_LNKCAP_SLS;
-		tmp |= PCI_EXP_LNKCAP_SLS_5_0GB;
+		tmp |= pci->link_gen;
 		dw_pcie_writel_dbi(pci, offset + PCI_EXP_LNKCAP, tmp);
 
 		/*
@@ -884,7 +884,7 @@ static int imx6_pcie_start_link(struct dw_pcie *pci)
 		if (ret)
 			goto err_reset_phy;
 	} else {
-		dev_info(dev, "Link: Gen2 disabled\n");
+		dev_info(dev, "Link: Only Gen1 is enabled\n");
 	}
 
 	imx6_pcie->link_is_up = true;
-- 
2.25.1