PCI: dwc: Stop link on host_init errors and de-initialization

It's logically correct to undo everything that was done when an error is
discovered or in the corresponding cleanup counterpart. Otherwise the host
controller will be left in an undetermined state. Since the link is set up
in the host_init method, deactivate it there in the cleanup-on-error block
and stop the link in the antagonistic routine - dw_pcie_host_deinit(). Link
deactivation is platform-specific and should be implemented in
dw_pcie_ops.stop_link().

Fixes: 886a9c13 ("PCI: dwc: Move link handling into common code")
Link: https://lore.kernel.org/r/20220624143428.8334-2-Sergey.Semin@baikalelectronics.ruTested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>

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

@@ -421,8 +421,14 @@ int dw_pcie_host_init(struct pcie_port *pp)
 	bridge->sysdata = pp;
 
 	ret = pci_host_probe(bridge);
-	if (!ret)
-		return 0;
+	if (ret)
+		goto err_stop_link;
+
+	return 0;
+
+err_stop_link:
+	if (pci->ops && pci->ops->stop_link)
+		pci->ops->stop_link(pci);
 
 err_free_msi:
 	if (pp->has_msi_ctrl)
@@ -433,8 +439,14 @@ EXPORT_SYMBOL_GPL(dw_pcie_host_init);
 
 void dw_pcie_host_deinit(struct pcie_port *pp)
 {
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+
 	pci_stop_root_bus(pp->bridge->bus);
 	pci_remove_root_bus(pp->bridge->bus);
+
+	if (pci->ops && pci->ops->stop_link)
+		pci->ops->stop_link(pci);
+
 	if (pp->has_msi_ctrl)
 		dw_pcie_free_msi(pp);
 }