usb: xhci-plat: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart from
emitting a warning) and this typically results in resource leaks. To improve
here there is a quest to make the remove callback return void. In the first
step of this quest all drivers are converted to .remove_new() which already
returns void. Eventually after all drivers are converted, .remove_new() is
renamed to .remove().

To convert the xhci-plat driver, change the prototype of
xhci_plat_remove() to return void. As this function is exported and used
by the xhci-rcar driver, convert this driver at the same time
accordingly.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230530071913.2192214-5-u.kleine-koenig@pengutronix.deSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/xhci-plat.c

@@ -395,7 +395,7 @@ static int xhci_generic_plat_probe(struct platform_device *pdev)
 	return xhci_plat_probe(pdev, sysdev, priv_match);
 }
 
-int xhci_plat_remove(struct platform_device *dev)
+void xhci_plat_remove(struct platform_device *dev)
 {
 	struct usb_hcd	*hcd = platform_get_drvdata(dev);
 	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
@@ -426,8 +426,6 @@ int xhci_plat_remove(struct platform_device *dev)
 	pm_runtime_disable(&dev->dev);
 	pm_runtime_put_noidle(&dev->dev);
 	pm_runtime_set_suspended(&dev->dev);
-
-	return 0;
 }
 EXPORT_SYMBOL_GPL(xhci_plat_remove);
 
@@ -526,7 +524,7 @@ MODULE_DEVICE_TABLE(acpi, usb_xhci_acpi_match);
 
 static struct platform_driver usb_generic_xhci_driver = {
 	.probe	= xhci_generic_plat_probe,
-	.remove	= xhci_plat_remove,
+	.remove_new = xhci_plat_remove,
 	.shutdown = usb_hcd_platform_shutdown,
 	.driver	= {
 		.name = "xhci-hcd",

drivers/usb/host/xhci-plat.h

@@ -25,7 +25,7 @@ struct xhci_plat_priv {
 int xhci_plat_probe(struct platform_device *pdev, struct device *sysdev,
 		    const struct xhci_plat_priv *priv_match);
 
-int xhci_plat_remove(struct platform_device *dev);
+void xhci_plat_remove(struct platform_device *dev);
 extern const struct dev_pm_ops xhci_plat_pm_ops;
 
 #endif	/* _XHCI_PLAT_H */

drivers/usb/host/xhci-rcar.c

@@ -276,10 +276,10 @@ static int xhci_renesas_probe(struct platform_device *pdev)
 }
 
 static struct platform_driver usb_xhci_renesas_driver = {
-	.probe	= xhci_renesas_probe,
-	.remove	= xhci_plat_remove,
+	.probe = xhci_renesas_probe,
+	.remove_new = xhci_plat_remove,
 	.shutdown = usb_hcd_platform_shutdown,
-	.driver	= {
+	.driver = {
 		.name = "xhci-renesas-hcd",
 		.pm = &xhci_plat_pm_ops,
 		.of_match_table = usb_xhci_of_match,