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Commit 74828b12 authored by Somnath Kotur's avatar Somnath Kotur Committed by Doug Ledford
Browse files

bnxt_re: Remove RTNL lock dependency in bnxt_re_query_port 



When there is a NETDEV_UNREGISTER event, bnxt_re driver calls
ib_unregister_device() (RTNL lock held).
ib_unregister_device attempts to flush a worker queue scheduled by
ib_core and that queue might have a pending ib_query_port().
ib_query_port in turn calls bnxt_re_query_port(), which while querying the
link speed using ib_get_eth_speed(), tries to acquire the rtnl_lock() which
was already held by NETDEV_UNREGISTER.
Fixing the issue by removing the link speed query from bnxt_re_query_port()
Now the speed is queried post a successful ib_register_device or whenever
there is a NETDEV_CHANGE event.

Signed-off-by: default avatarSomnath Kotur <somnath.kotur@broadcom.com>
Signed-off-by: default avatarDoug Ledford <dledford@redhat.com>
parent d5917307

drivers/infiniband/hw/bnxt_re/bnxt_re.h

+2 −0
Original line number Diff line number Diff line
@@ -110,6 +110,8 @@ struct bnxt_re_dev { 


	struct delayed_work		worker;

	u8				cur_prio_map;

	u8				active_speed;

	u8				active_width;



	/* FP Notification Queue (CQ & SRQ) */

	struct tasklet_struct		nq_task;

drivers/infiniband/hw/bnxt_re/ib_verbs.c

+3 −8
Original line number Diff line number Diff line
@@ -259,14 +259,9 @@ int bnxt_re_query_port(struct ib_device *ibdev, u8 port_num, 
	port_attr->sm_sl = 0;

	port_attr->subnet_timeout = 0;

	port_attr->init_type_reply = 0;

	/* call the underlying netdev's ethtool hooks to query speed settings

	 * for which we acquire rtnl_lock _only_ if it's registered with

	 * IB stack to avoid race in the NETDEV_UNREG path

	 */

	if (test_bit(BNXT_RE_FLAG_IBDEV_REGISTERED, &rdev->flags))

		if (ib_get_eth_speed(ibdev, port_num, &port_attr->active_speed,

				     &port_attr->active_width))

			return -EINVAL;

	port_attr->active_speed = rdev->active_speed;

	port_attr->active_width = rdev->active_width;



	return 0;

}

drivers/infiniband/hw/bnxt_re/main.c

+4 −0
Original line number Diff line number Diff line
@@ -1161,6 +1161,8 @@ static int bnxt_re_ib_reg(struct bnxt_re_dev *rdev) 
		}

	}

	set_bit(BNXT_RE_FLAG_IBDEV_REGISTERED, &rdev->flags);

	ib_get_eth_speed(&rdev->ibdev, 1, &rdev->active_speed,

			 &rdev->active_width);

	bnxt_re_dispatch_event(&rdev->ibdev, NULL, 1, IB_EVENT_PORT_ACTIVE);

	bnxt_re_dispatch_event(&rdev->ibdev, NULL, 1, IB_EVENT_GID_CHANGE);
@@ -1255,6 +1257,8 @@ static void bnxt_re_task(struct work_struct *work) 
		else if (netif_carrier_ok(rdev->netdev))

			bnxt_re_dispatch_event(&rdev->ibdev, NULL, 1,

					       IB_EVENT_PORT_ACTIVE);

		ib_get_eth_speed(&rdev->ibdev, 1, &rdev->active_speed,

				 &rdev->active_width);

		break;

	default:

		break;