net/mlx5: Add timeout handle to commands with callback

The current implementation does not handle timeout in case of command
with callback request, and this can lead to deadlock if the command
doesn't get fw response.
Add delayed callback timeout work before posting the command to fw.
In case of real fw command completion we will cancel the delayed work.
In case of fw command timeout the callback timeout handler will be
called and it will simulate fw completion with timeout error.

Fixes: e126ba97dba9 ('mlx5: Add driver for Mellanox Connect-IB adapters')
Signed-off-by: Mohamad Haj Yahia <mohamad@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/mlx5/driver.h b/include/linux/mlx5/driver.h
index 80776d0..fd72ecf 100644
--- a/include/linux/mlx5/driver.h
+++ b/include/linux/mlx5/driver.h
@@ -629,6 +629,7 @@
 	void		       *uout;
 	int			uout_size;
 	mlx5_cmd_cbk_t		callback;
+	struct delayed_work	cb_timeout_work;
 	void		       *context;
 	int			idx;
 	struct completion	done;