USB: move bus_suspend and bus_resume method calls

This patch (as885) moves the root-hub bus_suspend() and bus_resume()
method calls from the hub driver's suspend and resume methods into the
usb_generic driver methods, where they make just as much sense.

Their old locations were not fully correct.  For example, in a kernel
compiled without CONFIG_USB_SUSPEND, if one were to do:

	echo -n 1-0:1.0 >/sys/bus/usb/drivers/hub/unbind

to unbind the hub driver from a root hub, there would then be no way
to suspend that root hub.  Attempts to put the system to sleep would
fail; the USB controller driver would refuse to suspend because the
root hub was still active.

The patch also makes a very slight change in the way devices with no
driver are handled during suspend.  Rather than doing a standard USB
port-suspend directly, now the suspend routine in usb_generic is
called.  In practice this should never affect anyone.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

3 files changed, 43 insertions, 39 deletions

diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c
index 63d4794..e8b447e 100644
--- a/drivers/usb/core/driver.c
+++ b/drivers/usb/core/driver.c
@@ -802,14 +802,13 @@ static int usb_suspend_device(struct usb_device *udev, pm_message_t msg)
 			udev->state == USB_STATE_SUSPENDED)
 		goto done;
 
-	/* For devices that don't have a driver, we do a standard suspend. */
-	if (udev->dev.driver == NULL) {
+	/* For devices that don't have a driver, we do a generic suspend. */
+	if (udev->dev.driver)
+		udriver = to_usb_device_driver(udev->dev.driver);
+	else {
 		udev->do_remote_wakeup = 0;
-		status = usb_port_suspend(udev);
-		goto done;
+		udriver = &usb_generic_driver;
 	}
-
-	udriver = to_usb_device_driver(udev->dev.driver);
 	status = udriver->suspend(udev, msg);
 
 done:
diff --git a/drivers/usb/core/generic.c b/drivers/usb/core/generic.c
index e7ec9b6..7cbf992 100644
--- a/drivers/usb/core/generic.c
+++ b/drivers/usb/core/generic.c
@@ -19,6 +19,7 @@
 
 #include <linux/usb.h>
 #include "usb.h"
+#include "hcd.h"
 
 static inline const char *plural(int n)
 {
@@ -193,12 +194,46 @@ static void generic_disconnect(struct usb_device *udev)
 
 static int generic_suspend(struct usb_device *udev, pm_message_t msg)
 {
-	return usb_port_suspend(udev);
+	int rc;
+
+	rc = usb_port_suspend(udev);
+
+	/* Root hubs don't have upstream ports to suspend,
+	 * so the line above won't do much for them.  We have to
+	 * shut down their downstream HC-to-USB interfaces manually,
+	 * by doing a bus (or "global") suspend.
+	 */
+	if (rc == 0 && !udev->parent) {
+		rc = hcd_bus_suspend(udev->bus);
+		if (rc) {
+			dev_dbg(&udev->dev, "'global' suspend %d\n", rc);
+			usb_port_resume(udev);
+		}
+	}
+	return rc;
 }
 
 static int generic_resume(struct usb_device *udev)
 {
-	return usb_port_resume(udev);
+	int rc;
+
+	rc = usb_port_resume(udev);
+
+	/* Root hubs don't have upstream ports to resume or reset,
+	 * so the line above won't do much for them.  We have to
+	 * start up their downstream HC-to-USB interfaces manually,
+	 * by doing a bus (or "global") resume.
+	 */
+	if (rc == 0 && !udev->parent) {
+		rc = hcd_bus_resume(udev->bus);
+		if (rc)
+			dev_dbg(&udev->dev, "'global' resume %d\n", rc);
+		else {
+			/* TRSMRCY = 10 msec */
+			msleep(10);
+		}
+	}
+	return rc;
 }
 
 #endif	/* CONFIG_PM */
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index a9cf8b3..8aea855 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1916,7 +1916,6 @@ static int hub_suspend(struct usb_interface *intf, pm_message_t msg)
 	struct usb_hub		*hub = usb_get_intfdata (intf);
 	struct usb_device	*hdev = hub->hdev;
 	unsigned		port1;
-	int			status = 0;
 
 	/* fail if children aren't already suspended */
 	for (port1 = 1; port1 <= hdev->maxchild; port1++) {
@@ -1942,44 +1941,15 @@ static int hub_suspend(struct usb_interface *intf, pm_message_t msg)
 
 	/* stop khubd and related activity */
 	hub_quiesce(hub);
-
-	/* "global suspend" of the downstream HC-to-USB interface */
-	if (!hdev->parent) {
-		status = hcd_bus_suspend(hdev->bus);
-		if (status != 0) {
-			dev_dbg(&hdev->dev, "'global' suspend %d\n", status);
-			hub_activate(hub);
-		}
-	}
-	return status;
+	return 0;
 }
 
 static int hub_resume(struct usb_interface *intf)
 {
 	struct usb_hub		*hub = usb_get_intfdata (intf);
-	struct usb_device	*hdev = hub->hdev;
-	int			status;
 
 	dev_dbg(&intf->dev, "%s\n", __FUNCTION__);
 
-	/* "global resume" of the downstream HC-to-USB interface */
-	if (!hdev->parent) {
-		struct usb_bus	*bus = hdev->bus;
-		if (bus) {
-			status = hcd_bus_resume (bus);
-			if (status) {
-				dev_dbg(&intf->dev, "'global' resume %d\n",
-					status);
-				return status;
-			}
-		} else
-			return -EOPNOTSUPP;
-		if (status == 0) {
-			/* TRSMRCY = 10 msec */
-			msleep(10);
-		}
-	}
-
 	/* tell khubd to look for changes on this hub */
 	hub_activate(hub);
 	return 0;