PCI: imx6: Call dw_pcie_wait_for_link() from start_link() callback only when required

Since the DWC driver is already calling dw_pcie_wait_for_link() after
calling the start_link() callback, remove the redundant
dw_pcie_wait_for_link() call from imx_pcie_start_link(). It is still
required to call this function for controllers supporting Gen 2 and higher
link speeds.

Suggested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
[mani: subject and description rewording]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20250416081314.3929794-3-hongxing.zhu@nxp.com

Author: Richard Zhu

drivers/pci/controller/dwc/pci-imx6.c

@@ -881,11 +881,11 @@ static int imx_pcie_start_link(struct dw_pcie *pci)
 	/* Start LTSSM. */
 	imx_pcie_ltssm_enable(dev);
 
-	ret = dw_pcie_wait_for_link(pci);
-	if (ret)
-		goto err_reset_phy;
-
 	if (pci->max_link_speed > 1) {
+		ret = dw_pcie_wait_for_link(pci);
+		if (ret)
+			goto err_reset_phy;
+
 		/* 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);
@@ -907,17 +907,10 @@ static int imx_pcie_start_link(struct dw_pcie *pci)
 			dev_err(dev, "Failed to bring link up!\n");
 			goto err_reset_phy;
 		}
-
-		/* Make sure link training is finished as well! */
-		ret = dw_pcie_wait_for_link(pci);
-		if (ret)
-			goto err_reset_phy;
 	} else {
 		dev_info(dev, "Link: Only Gen1 is enabled\n");
 	}
 
-	tmp = dw_pcie_readw_dbi(pci, offset + PCI_EXP_LNKSTA);
-	dev_info(dev, "Link up, Gen%i\n", tmp & PCI_EXP_LNKSTA_CLS);
 	return 0;
 
 err_reset_phy: