diff options
Diffstat (limited to 'drivers/net/can/sja1000')
| -rw-r--r-- | drivers/net/can/sja1000/sja1000.c | 20 | ||||
| -rw-r--r-- | drivers/net/can/sja1000/sja1000.h | 1 |
2 files changed, 18 insertions, 3 deletions
diff --git a/drivers/net/can/sja1000/sja1000.c b/drivers/net/can/sja1000/sja1000.c index 16d2ecd2a3b7..9463e5db9566 100644 --- a/drivers/net/can/sja1000/sja1000.c +++ b/drivers/net/can/sja1000/sja1000.c @@ -84,6 +84,20 @@ static struct can_bittiming_const sja1000_bittiming_const = { .brp_inc = 1, }; +static void sja1000_write_cmdreg(struct sja1000_priv *priv, u8 val) +{ + unsigned long flags; + + /* + * The command register needs some locking and time to settle + * the write_reg() operation - especially on SMP systems. + */ + spin_lock_irqsave(&priv->cmdreg_lock, flags); + priv->write_reg(priv, REG_CMR, val); + priv->read_reg(priv, REG_SR); + spin_unlock_irqrestore(&priv->cmdreg_lock, flags); +} + static int sja1000_probe_chip(struct net_device *dev) { struct sja1000_priv *priv = netdev_priv(dev); @@ -279,7 +293,7 @@ static netdev_tx_t sja1000_start_xmit(struct sk_buff *skb, can_put_echo_skb(skb, dev, 0); - priv->write_reg(priv, REG_CMR, CMD_TR); + sja1000_write_cmdreg(priv, CMD_TR); return NETDEV_TX_OK; } @@ -334,7 +348,7 @@ static void sja1000_rx(struct net_device *dev) cf->data[i++] = 0; /* release receive buffer */ - priv->write_reg(priv, REG_CMR, CMD_RRB); + sja1000_write_cmdreg(priv, CMD_RRB); netif_rx(skb); @@ -368,7 +382,7 @@ static int sja1000_err(struct net_device *dev, uint8_t isrc, uint8_t status) cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; stats->rx_over_errors++; stats->rx_errors++; - priv->write_reg(priv, REG_CMR, CMD_CDO); /* clear bit */ + sja1000_write_cmdreg(priv, CMD_CDO); /* clear bit */ } if (isrc & IRQ_EI) { diff --git a/drivers/net/can/sja1000/sja1000.h b/drivers/net/can/sja1000/sja1000.h index 302d2c763ad7..cfd3f57e4ab5 100644 --- a/drivers/net/can/sja1000/sja1000.h +++ b/drivers/net/can/sja1000/sja1000.h @@ -165,6 +165,7 @@ struct sja1000_priv { void __iomem *reg_base; /* ioremap'ed address to registers */ unsigned long irq_flags; /* for request_irq() */ + spinlock_t cmdreg_lock; /* lock for concurrent cmd register writes */ u16 flags; /* custom mode flags */ u8 ocr; /* output control register */ |