USB: fix locking loop by avoiding flush_scheduled_work

This patch (as1027) replaces a call to flush_scheduled_work() -- a
dangerous routine to invoke, especially while holding any sort of lock
-- with calls to cancel_work_sync() and cancel_delayed_work_sync().

This fixes Bugzilla #9532.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: David Brownell <david-b@pacbell.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 3 insertions, 3 deletions

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 13b326a13377..b04d232d4c65 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -522,9 +522,9 @@ static void hub_quiesce(struct usb_hub *hub)
         /* (blocking) stop khubd and related activity */
         usb_kill_urb(hub->urb);
         if (hub->has_indicators)
-                cancel_delayed_work(&hub->leds);
-        if (hub->has_indicators || hub->tt.hub)
-                flush_scheduled_work();
+                cancel_delayed_work_sync(&hub->leds);
+        if (hub->tt.hub)
+                cancel_work_sync(&hub->tt.kevent);
 }
 
 static void hub_activate(struct usb_hub *hub)