Merge commit 'v3.2-rc3' into next

1 files changed, 13 insertions, 3 deletions

diff --git a/drivers/usb/storage/usb.c b/drivers/usb/storage/usb.c
index 0ca095820f3e..c325e69415a1 100644
--- a/drivers/usb/storage/usb.c
+++ b/drivers/usb/storage/usb.c
@@ -831,12 +831,22 @@ static int usb_stor_scan_thread(void * __us)
 
         dev_dbg(dev, "device found\n");
 
-        set_freezable();
-        /* Wait for the timeout to expire or for a disconnect */
+        set_freezable_with_signal();
+        /*
+         * Wait for the timeout to expire or for a disconnect
+         *
+         * We can't freeze in this thread or we risk causing khubd to
+         * fail to freeze, but we can't be non-freezable either. Nor can
+         * khubd freeze while waiting for scanning to complete as it may
+         * hold the device lock, causing a hang when suspending devices.
+         * So we request a fake signal when freezing and use
+         * interruptible sleep to kick us out of our wait early when
+         * freezing happens.
+         */
         if (delay_use > 0) {
                 dev_dbg(dev, "waiting for device to settle "
                                 "before scanning\n");
-                wait_event_freezable_timeout(us->delay_wait,
+                wait_event_interruptible_timeout(us->delay_wait,
                                 test_bit(US_FLIDX_DONT_SCAN, &us->dflags),
                                 delay_use * HZ);
         }