From: Selvin Xavier <selvin.xavier@broadcom.com>
Date: Thu, 15 Feb 2018 21:20:13 -0800
Subject: RDMA/bnxt_re: Avoid system hang during device un-reg
Patch-mainline: v4.16-rc3
Git-commit: 7374fbd9e167ddc4f380d056ca74518be5d45518
References: bsc#1050244 FATE#322915
BNXT_RE_FLAG_TASK_IN_PROG doesn't handle multiple work
requests posted together. Track schedule of multiple
workqueue items by maintaining a per device counter
and proceed with IB dereg only if this counter is zero.
flush_workqueue is no longer required from
NETDEV_UNREGISTER path.
Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/infiniband/hw/bnxt_re/bnxt_re.h | 2 +-
drivers/infiniband/hw/bnxt_re/main.c | 7 +++----
2 files changed, 4 insertions(+), 5 deletions(-)
--- a/drivers/infiniband/hw/bnxt_re/bnxt_re.h
+++ b/drivers/infiniband/hw/bnxt_re/bnxt_re.h
@@ -120,7 +120,6 @@ struct bnxt_re_dev {
#define BNXT_RE_FLAG_HAVE_L2_REF 3
#define BNXT_RE_FLAG_RCFW_CHANNEL_EN 4
#define BNXT_RE_FLAG_QOS_WORK_REG 5
-#define BNXT_RE_FLAG_TASK_IN_PROG 6
#define BNXT_RE_FLAG_ISSUE_ROCE_STATS 29
struct net_device *netdev;
unsigned int version, major, minor;
@@ -158,6 +157,7 @@ struct bnxt_re_dev {
atomic_t srq_count;
atomic_t mr_count;
atomic_t mw_count;
+ atomic_t sched_count;
/* Max of 2 lossless traffic class supported per port */
u16 cosq[2];
--- a/drivers/infiniband/hw/bnxt_re/main.c
+++ b/drivers/infiniband/hw/bnxt_re/main.c
@@ -656,7 +656,6 @@ static void bnxt_re_dev_remove(struct bn
mutex_unlock(&bnxt_re_dev_lock);
synchronize_rcu();
- flush_workqueue(bnxt_re_wq);
ib_dealloc_device(&rdev->ibdev);
/* rdev is gone */
@@ -1441,7 +1440,7 @@ static void bnxt_re_task(struct work_str
break;
}
smp_mb__before_atomic();
- clear_bit(BNXT_RE_FLAG_TASK_IN_PROG, &rdev->flags);
+ atomic_dec(&rdev->sched_count);
kfree(re_work);
}
@@ -1503,7 +1502,7 @@ static int bnxt_re_netdev_event(struct n
/* netdev notifier will call NETDEV_UNREGISTER again later since
* we are still holding the reference to the netdev
*/
- if (test_bit(BNXT_RE_FLAG_TASK_IN_PROG, &rdev->flags))
+ if (atomic_read(&rdev->sched_count) > 0)
goto exit;
bnxt_re_ib_unreg(rdev, false);
bnxt_re_remove_one(rdev);
@@ -1523,7 +1522,7 @@ static int bnxt_re_netdev_event(struct n
re_work->vlan_dev = (real_dev == netdev ?
NULL : netdev);
INIT_WORK(&re_work->work, bnxt_re_task);
- set_bit(BNXT_RE_FLAG_TASK_IN_PROG, &rdev->flags);
+ atomic_inc(&rdev->sched_count);
queue_work(bnxt_re_wq, &re_work->work);
}
}