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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: Somnath Kotur <somnath.kotur@broadcom.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
This commit is contained in:
Somnath Kotur 2017-08-31 09:27:33 +05:30 committed by Doug Ledford
parent d5917307bb
commit 74828b1281
3 changed files with 9 additions and 8 deletions
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2
drivers/infiniband/hw/bnxt_re/bnxt_re.h
View File

@ -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;

11
drivers/infiniband/hw/bnxt_re/ib_verbs.c
View File

@ -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;
}

4
drivers/infiniband/hw/bnxt_re/main.c
View File

@ -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;