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>

1 files changed, 37 insertions, 2 deletions

diff --git a/drivers/usb/core/generic.c b/drivers/usb/core/generic.c
index e7ec9b6b7a93..7cbf992adccd 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 */