mISDN: Fix wrong usage of flush_work_sync while holding locks

It is a bad idea to hold a spinlock and call flush_work_sync.
Move the workqueue cleanup outside the spinlock and use cancel_work_sync,
on closing the channel this seems to be the more correct function.
Remove the never used and constant return value of mISDN_freebchannel.

Signed-off-by: Karsten Keil <keil@b1-systems.de>
Cc: <stable@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/isdn/hardware/mISDN/mISDNisar.c b/drivers/isdn/hardware/mISDN/mISDNisar.c
index be5973ded6d6..182ecf0626c2 100644
--- a/drivers/isdn/hardware/mISDN/mISDNisar.c
+++ b/drivers/isdn/hardware/mISDN/mISDNisar.c
@@ -1588,8 +1588,9 @@ isar_bctrl(struct mISDNchannel *ch, u32 cmd, void *arg)
         switch (cmd) {
         case CLOSE_CHANNEL:
                 test_and_clear_bit(FLG_OPEN, &bch->Flags);
+                cancel_work_sync(&bch->workq);
                 spin_lock_irqsave(ich->is->hwlock, flags);
-                mISDN_freebchannel(bch);
+                mISDN_clear_bchannel(bch);
                 modeisar(ich, ISDN_P_NONE);
                 spin_unlock_irqrestore(ich->is->hwlock, flags);
                 ch->protocol = ISDN_P_NONE;