Merge branch 'pci/controller/dwc'

- Wait for link to come up only if we've initiated link training (Ajay
  Agarwal)

- Save and restore imx6 Root Port MSI control to work around hardware
  defect (Richard Zhu)

* pci/controller/dwc:
  PCI: imx6: Save and restore root port MSI control in suspend and resume
  PCI: dwc: Wait for link up only if link is started

Author: bjorn-helgaas

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

@@ -80,6 +80,7 @@ struct imx6_pcie {
 	struct clk		*pcie;
 	struct clk		*pcie_aux;
 	struct regmap		*iomuxc_gpr;
+	u16			msi_ctrl;
 	u32			controller_id;
 	struct reset_control	*pciephy_reset;
 	struct reset_control	*apps_reset;
@@ -1178,6 +1179,26 @@ static void imx6_pcie_pm_turnoff(struct imx6_pcie *imx6_pcie)
 	usleep_range(1000, 10000);
 }
 
+static void imx6_pcie_msi_save_restore(struct imx6_pcie *imx6_pcie, bool save)
+{
+	u8 offset;
+	u16 val;
+	struct dw_pcie *pci = imx6_pcie->pci;
+
+	if (pci_msi_enabled()) {
+		offset = dw_pcie_find_capability(pci, PCI_CAP_ID_MSI);
+		if (save) {
+			val = dw_pcie_readw_dbi(pci, offset + PCI_MSI_FLAGS);
+			imx6_pcie->msi_ctrl = val;
+		} else {
+			dw_pcie_dbi_ro_wr_en(pci);
+			val = imx6_pcie->msi_ctrl;
+			dw_pcie_writew_dbi(pci, offset + PCI_MSI_FLAGS, val);
+			dw_pcie_dbi_ro_wr_dis(pci);
+		}
+	}
+}
+
 static int imx6_pcie_suspend_noirq(struct device *dev)
 {
 	struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
@@ -1186,6 +1207,7 @@ static int imx6_pcie_suspend_noirq(struct device *dev)
 	if (!(imx6_pcie->drvdata->flags & IMX6_PCIE_FLAG_SUPPORTS_SUSPEND))
 		return 0;
 
+	imx6_pcie_msi_save_restore(imx6_pcie, true);
 	imx6_pcie_pm_turnoff(imx6_pcie);
 	imx6_pcie_stop_link(imx6_pcie->pci);
 	imx6_pcie_host_exit(pp);
@@ -1205,6 +1227,7 @@ static int imx6_pcie_resume_noirq(struct device *dev)
 	ret = imx6_pcie_host_init(pp);
 	if (ret)
 		return ret;
+	imx6_pcie_msi_save_restore(imx6_pcie, false);
 	dw_pcie_setup_rc(pp);
 
 	if (imx6_pcie->link_is_up)

drivers/pci/controller/dwc/pcie-designware-host.c

@@ -485,14 +485,19 @@ int dw_pcie_host_init(struct dw_pcie_rp *pp)
 	if (ret)
 		goto err_remove_edma;
 
-	if (!dw_pcie_link_up(pci)) {
+	if (dw_pcie_link_up(pci)) {
+		dw_pcie_print_link_status(pci);
+	} else {
 		ret = dw_pcie_start_link(pci);
 		if (ret)
 			goto err_remove_edma;
-	}
 
-	/* Ignore errors, the link may come up later */
-	dw_pcie_wait_for_link(pci);
+		if (pci->ops && pci->ops->start_link) {
+			ret = dw_pcie_wait_for_link(pci);
+			if (ret)
+				goto err_stop_link;
+		}
+	}
 
 	bridge->sysdata = pp;
 

drivers/pci/controller/dwc/pcie-designware.c

@@ -644,9 +644,20 @@ void dw_pcie_disable_atu(struct dw_pcie *pci, u32 dir, int index)
 	dw_pcie_writel_atu(pci, dir, index, PCIE_ATU_REGION_CTRL2, 0);
 }
 
-int dw_pcie_wait_for_link(struct dw_pcie *pci)
+void dw_pcie_print_link_status(struct dw_pcie *pci)
 {
 	u32 offset, val;
+
+	offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
+	val = dw_pcie_readw_dbi(pci, offset + PCI_EXP_LNKSTA);
+
+	dev_info(pci->dev, "PCIe Gen.%u x%u link up\n",
+		 FIELD_GET(PCI_EXP_LNKSTA_CLS, val),
+		 FIELD_GET(PCI_EXP_LNKSTA_NLW, val));
+}
+
+int dw_pcie_wait_for_link(struct dw_pcie *pci)
+{
 	int retries;
 
 	/* Check if the link is up or not */
@@ -662,12 +673,7 @@ int dw_pcie_wait_for_link(struct dw_pcie *pci)
 		return -ETIMEDOUT;
 	}
 
-	offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
-	val = dw_pcie_readw_dbi(pci, offset + PCI_EXP_LNKSTA);
-
-	dev_info(pci->dev, "PCIe Gen.%u x%u link up\n",
-		 FIELD_GET(PCI_EXP_LNKSTA_CLS, val),
-		 FIELD_GET(PCI_EXP_LNKSTA_NLW, val));
+	dw_pcie_print_link_status(pci);
 
 	return 0;
 }

drivers/pci/controller/dwc/pcie-designware.h

@@ -429,6 +429,7 @@ void dw_pcie_setup(struct dw_pcie *pci);
 void dw_pcie_iatu_detect(struct dw_pcie *pci);
 int dw_pcie_edma_detect(struct dw_pcie *pci);
 void dw_pcie_edma_remove(struct dw_pcie *pci);
+void dw_pcie_print_link_status(struct dw_pcie *pci);
 
 static inline void dw_pcie_writel_dbi(struct dw_pcie *pci, u32 reg, u32 val)
 {