diff options
| author | Dmitry Tarnyagin <dmitry.tarnyagin@stericsson.com> | 2011-10-13 13:29:24 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2011-10-19 09:25:41 +0200 |
| commit | 73033c987a8bd0b080509063bb7c130b8941ad73 (patch) | |
| tree | 3fc3b0f7160c9f9659eed18721b6770468def367 | |
| parent | caif-hsi: Fixing a race condition in the caif_hsi code (diff) | |
| download | linux-73033c987a8bd0b080509063bb7c130b8941ad73.tar.xz linux-73033c987a8bd0b080509063bb7c130b8941ad73.zip | |
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 <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | drivers/net/caif/caif_hsi.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/drivers/net/caif/caif_hsi.c b/drivers/net/caif/caif_hsi.c index 36da27b50114..82c4d6ca2d3f 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; |