From 4bb073c0e32a0862bdb5215d11af19f6c0180c98 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Thu, 12 Jun 2008 02:22:02 -0700 Subject: net: Eliminate flush_scheduled_work() calls while RTNL is held. If the RTNL is held when we invoke flush_scheduled_work() we could deadlock. One such case is linkwatch, it is a work struct which tries to grab the RTNL semaphore. The most common case are net driver ->stop() methods. The simplest conversion is to instead use cancel_{delayed_}work_sync() explicitly on the various work struct the driver uses. This is an OK transformation because these work structs are doing things like resetting the chip, restarting link negotiation, and so forth. And if we're bringing down the device, we're about to turn the chip off and reset it anways. So if we cancel a pending work event, that's fine here. Some drivers were working around this deadlock by using a msleep() polling loop of some sort, and those cases are converted to instead use cancel_{delayed_}work_sync() as well. Signed-off-by: David S. Miller --- drivers/net/bnx2.c | 9 +-------- 1 file changed, 1 insertion(+), 8 deletions(-) (limited to 'drivers/net/bnx2.c') diff --git a/drivers/net/bnx2.c b/drivers/net/bnx2.c index 4b46e68183e0..367b6d462708 100644 --- a/drivers/net/bnx2.c +++ b/drivers/net/bnx2.c @@ -5724,14 +5724,12 @@ bnx2_reset_task(struct work_struct *work) if (!netif_running(bp->dev)) return; - bp->in_reset_task = 1; bnx2_netif_stop(bp); bnx2_init_nic(bp); atomic_set(&bp->intr_sem, 1); bnx2_netif_start(bp); - bp->in_reset_task = 0; } static void @@ -5907,12 +5905,7 @@ bnx2_close(struct net_device *dev) struct bnx2 *bp = netdev_priv(dev); u32 reset_code; - /* Calling flush_scheduled_work() may deadlock because - * linkwatch_event() may be on the workqueue and it will try to get - * the rtnl_lock which we are holding. - */ - while (bp->in_reset_task) - msleep(1); + cancel_work_sync(&bp->reset_task); bnx2_disable_int_sync(bp); bnx2_napi_disable(bp); -- cgit v1.2.3