From 7374fbd9e167ddc4f380d056ca74518be5d45518 Mon Sep 17 00:00:00 2001 From: Selvin Xavier Date: Thu, 15 Feb 2018 21:20:13 -0800 Subject: [PATCH] RDMA/bnxt_re: Avoid system hang during device un-reg 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 Signed-off-by: Doug Ledford --- drivers/infiniband/hw/bnxt_re/bnxt_re.h | 2 +- drivers/infiniband/hw/bnxt_re/main.c | 7 +++---- 2 files changed, 4 insertions(+), 5 deletions(-) diff --git a/drivers/infiniband/hw/bnxt_re/bnxt_re.h b/drivers/infiniband/hw/bnxt_re/bnxt_re.h index ca32057e886f..3eb7a8387116 100644 --- 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]; diff --git a/drivers/infiniband/hw/bnxt_re/main.c b/drivers/infiniband/hw/bnxt_re/main.c index 7f9298db507b..33a448036c2e 100644 --- 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 bnxt_re_dev *rdev) 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_struct *work) 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 notifier_block *notifier, /* 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 notifier_block *notifier, 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); } }