USB: make the autosuspend workqueue thread freezable

This patch (as881b) makes the ksuspend_usb_wq workqueue freezable. We
don't want a rogue workqueue thread running around, unexpectedly
suspending or resuming USB devices in the middle of a system sleep
transition.

This fixes Bugzilla #8498.

Signed-off-by: Alan Stern <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/core/usb.c

···
 
 static int ksuspend_usb_init(void)
 {
-	ksuspend_usb_wq = create_singlethread_workqueue("ksuspend_usbd");
+	/* This workqueue is supposed to be both freezable and
+	 * singlethreaded.  Its job doesn't justify running on more
+	 * than one CPU.
+	 */
+	ksuspend_usb_wq = create_freezeable_workqueue("ksuspend_usbd");
 	if (!ksuspend_usb_wq)
 		return -ENOMEM;
 	return 0;