From: Dmitry Tarnyagin Date: Thu, 13 Oct 2011 11:29:24 +0000 (+0000) Subject: caif-hsi: Fix for wakeup condition problem X-Git-Tag: master-2011-11-08~137 X-Git-Url: http://pileus.org/git/?a=commitdiff_plain;h=73033c987a8bd0b080509063bb7c130b8941ad73;p=~andy%2Flinux caif-hsi: Fix for wakeup condition problem Under stressed conditions a race could happen when del_timer_sync() was called from softirq context at the same time when mod_timer_pending() for the same timer was called from the workqueue. This leaded to a state mismatch in the CAIF HSI driver and following unexpected link wakeup procedure. The fix puts del_timer_sync() and mod_timer_pending() calls under a spin lock to protect against the race condition. Signed-off-by: Sjur Brændeland Signed-off-by: David S. Miller --- diff --git a/drivers/net/caif/caif_hsi.c b/drivers/net/caif/caif_hsi.c index 36da27b5011..82c4d6ca2d3 100644 --- a/drivers/net/caif/caif_hsi.c +++ b/drivers/net/caif/caif_hsi.c @@ -551,7 +551,9 @@ static void cfhsi_rx_done_work(struct work_struct *work) return; /* Update inactivity timer if pending. */ + spin_lock_bh(&cfhsi->lock); mod_timer_pending(&cfhsi->timer, jiffies + CFHSI_INACTIVITY_TOUT); + spin_unlock_bh(&cfhsi->lock); if (cfhsi->rx_state == CFHSI_RX_STATE_DESC) { desc_pld_len = cfhsi_rx_desc(desc, cfhsi); @@ -866,10 +868,10 @@ static int cfhsi_xmit(struct sk_buff *skb, struct net_device *dev) start_xfer = 1; } - spin_unlock_bh(&cfhsi->lock); - - if (!start_xfer) + if (!start_xfer) { + spin_unlock_bh(&cfhsi->lock); return 0; + } /* Delete inactivity timer if started. */ #ifdef CONFIG_SMP @@ -878,6 +880,8 @@ static int cfhsi_xmit(struct sk_buff *skb, struct net_device *dev) timer_active = del_timer(&cfhsi->timer); #endif /* CONFIG_SMP */ + spin_unlock_bh(&cfhsi->lock); + if (timer_active) { struct cfhsi_desc *desc = (struct cfhsi_desc *)cfhsi->tx_buf; int len;