diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2014-03-18 17:19:12 +0000 |
|---|---|---|
| committer | Marc Kleine-Budde <mkl@pengutronix.de> | 2014-04-01 11:55:00 +0200 |
| commit | bf88a20611d5a62119a02da4eba95b461ec692c8 (patch) | |
| tree | f1ee16ea5621c98799fdf17f5b102474a77b4e8e /drivers | |
| parent | 710c56105dfd10e32a89086cf78cc1c8433f6a7a (diff) | |
can: c_can: Provide protection in the xmit path
The network core does not serialize the access to the hardware. The
xmit related code lets the following happen:
CPU0 CPU1
interrupt()
do_poll()
c_can_do_tx()
Fiddle with HW and xmit()
internal data Fiddle with HW and
internal data
due the complete lack of serialization.
Add proper locking.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/can/c_can/c_can.c | 9 | ||||
| -rw-r--r-- | drivers/net/can/c_can/c_can.h | 1 |
2 files changed, 9 insertions, 1 deletions
diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c index 30a85aa81d4..1fe79ce50c5 100644 --- a/drivers/net/can/c_can/c_can.c +++ b/drivers/net/can/c_can/c_can.c @@ -549,6 +549,7 @@ static netdev_tx_t c_can_start_xmit(struct sk_buff *skb, if (can_dropped_invalid_skb(dev, skb)) return NETDEV_TX_OK; + spin_lock_bh(&priv->xmit_lock); msg_obj_no = get_tx_next_msg_obj(priv); /* prepare message object for transmission */ @@ -563,6 +564,7 @@ static netdev_tx_t c_can_start_xmit(struct sk_buff *skb, if (c_can_is_next_tx_obj_busy(priv, get_tx_next_msg_obj(priv)) || (priv->tx_next & C_CAN_NEXT_MSG_OBJ_MASK) == 0) netif_stop_queue(dev); + spin_unlock_bh(&priv->xmit_lock); return NETDEV_TX_OK; } @@ -787,7 +789,9 @@ static void c_can_do_tx(struct net_device *dev) struct c_can_priv *priv = netdev_priv(dev); struct net_device_stats *stats = &dev->stats; - for (/* nix */; (priv->tx_next - priv->tx_echo) > 0; priv->tx_echo++) { + spin_lock_bh(&priv->xmit_lock); + + for (; (priv->tx_next - priv->tx_echo) > 0; priv->tx_echo++) { msg_obj_no = get_tx_echo_msg_obj(priv); val = c_can_read_reg32(priv, C_CAN_TXRQST1_REG); if (!(val & (1 << (msg_obj_no - 1)))) { @@ -809,6 +813,8 @@ static void c_can_do_tx(struct net_device *dev) if (((priv->tx_next & C_CAN_NEXT_MSG_OBJ_MASK) != 0) || ((priv->tx_echo & C_CAN_NEXT_MSG_OBJ_MASK) == 0)) netif_wake_queue(dev); + + spin_unlock_bh(&priv->xmit_lock); } /* @@ -1262,6 +1268,7 @@ struct net_device *alloc_c_can_dev(void) return NULL; priv = netdev_priv(dev); + spin_lock_init(&priv->xmit_lock); netif_napi_add(dev, &priv->napi, c_can_poll, C_CAN_NAPI_WEIGHT); priv->dev = dev; diff --git a/drivers/net/can/c_can/c_can.h b/drivers/net/can/c_can/c_can.h index d2e1c21b143..5097c802a61 100644 --- a/drivers/net/can/c_can/c_can.h +++ b/drivers/net/can/c_can/c_can.h @@ -156,6 +156,7 @@ struct c_can_priv { struct napi_struct napi; struct net_device *dev; struct device *device; + spinlock_t xmit_lock; int tx_object; int current_status; int last_status; |