From: Eric Dumazet <redacted>
Date: Fri, 26 Jun 2015 07:32:29 +0200

From: Eric Dumazet <edumazet@google.com>

Michel reported following lockdep splat

 ...

As bnx2x_init_ptp() is only called if bp->flags contains PTP_SUPPORTED,
we also need to guard bnx2x_stop_ptp() with same condition, otherwise
ptp_task workqueue is not initialized and kernel barfs on
cancel_work_sync()

Fixes: eeed018cbfa30 ("bnx2x: Add timestamping and PTP hardware clock support")
Reported-by: Michel Lespinasse <redacted> 
Signed-off-by: Eric Dumazet <edumazet@google.com>

Applied and queued up for -stable, thanks.