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>
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 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 */