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

1 files changed, 5 insertions, 1 deletions

diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
index 18ddc5e67e39..80627b6a2bf9 100644
--- a/drivers/usb/core/usb.c
+++ b/drivers/usb/core/usb.c
@@ -205,7 +205,11 @@ struct device_type usb_device_type = {
 
 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;