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path: root/drivers/net/can/sja1000/sja1000.c
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Diffstat (limited to 'drivers/net/can/sja1000/sja1000.c')
-rw-r--r--drivers/net/can/sja1000/sja1000.c23
1 files changed, 17 insertions, 6 deletions
diff --git a/drivers/net/can/sja1000/sja1000.c b/drivers/net/can/sja1000/sja1000.c
index 145b1a731a5..85f7cbfe8e5 100644
--- a/drivers/net/can/sja1000/sja1000.c
+++ b/drivers/net/can/sja1000/sja1000.c
@@ -60,7 +60,6 @@
#include <linux/skbuff.h>
#include <linux/delay.h>
-#include <linux/can.h>
#include <linux/can/dev.h>
#include <linux/can/error.h>
@@ -84,6 +83,20 @@ 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);
@@ -293,11 +306,9 @@ static netdev_tx_t sja1000_start_xmit(struct sk_buff *skb,
for (i = 0; i < dlc; i++)
priv->write_reg(priv, dreg++, cf->data[i]);
- dev->trans_start = jiffies;
-
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;
}
@@ -346,7 +357,7 @@ static void sja1000_rx(struct net_device *dev)
cf->can_id = id;
/* release receive buffer */
- priv->write_reg(priv, REG_CMR, CMD_RRB);
+ sja1000_write_cmdreg(priv, CMD_RRB);
netif_rx(skb);
@@ -374,7 +385,7 @@ 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) {