USB: improve uses of usb_mark_last_busy

This patch (as1434) cleans up the uses of usb_mark_last_busy() in
usbcore.  The function will be called when a device is resumed and
whenever a usage count is decremented.  A call that was missing from
the hub driver is added: A hub is used whenever one of its ports gets
suspended (this prevents hubs from suspending immediately after their
last child).

In addition, the call to disable autosuspend support for new devices
by default is moved from usb_detect_quirks() (where it doesn't really
belong) into usb_new_device() along with all the other runtime-PM
initializations.  Finally, an extra pm_runtime_get_noresume() is added
to prevent new devices from autosuspending while they are being
registered.

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

1 files changed, 9 insertions, 0 deletions

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index fdb62ca..b98efae 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1803,9 +1803,15 @@ int usb_new_device(struct usb_device *udev)
 
 	/* Tell the runtime-PM framework the device is active */
 	pm_runtime_set_active(&udev->dev);
+	pm_runtime_get_noresume(&udev->dev);
 	pm_runtime_use_autosuspend(&udev->dev);
 	pm_runtime_enable(&udev->dev);
 
+	/* By default, forbid autosuspend for all devices.  It will be
+	 * allowed for hubs during binding.
+	 */
+	usb_disable_autosuspend(udev);
+
 	err = usb_enumerate_device(udev);	/* Read descriptors */
 	if (err < 0)
 		goto fail;
@@ -1831,6 +1837,8 @@ int usb_new_device(struct usb_device *udev)
 	}
 
 	(void) usb_create_ep_devs(&udev->dev, &udev->ep0, udev);
+	usb_mark_last_busy(udev);
+	pm_runtime_put_sync_autosuspend(&udev->dev);
 	return err;
 
 fail:
@@ -2221,6 +2229,7 @@ int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
 		usb_set_device_state(udev, USB_STATE_SUSPENDED);
 		msleep(10);
 	}
+	usb_mark_last_busy(hub->hdev);
 	return status;
 }