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authorDavid S. Miller <davem@davemloft.net>2018-03-14 13:50:47 -0400
committerDavid S. Miller <davem@davemloft.net>2018-03-14 13:50:47 -0400
commit4ea41f829a69828565b75515a091b394d5dc5116 (patch)
tree0e408fb22ba5389b2e655d1200023d4031222478
parentea91df6d8a55836c7401eb6d5d4d828b659d8d67 (diff)
parent746201235b3f876792099079f4c6fea941d76183 (diff)
Merge tag 'linux-can-fixes-for-4.16-20180314' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can
Marc Kleine-Budde says: ==================== pull-request: can 2018-03-14 this is a pull request of two patches for net/master. Both patches are by Andri Yngvason and fix problems in the cc770 driver, that show up quite fast on RT systems, but also on non RT setups. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/can/cc770/cc770.c103
-rw-r--r--drivers/net/can/cc770/cc770.h2
2 files changed, 65 insertions, 40 deletions
diff --git a/drivers/net/can/cc770/cc770.c b/drivers/net/can/cc770/cc770.c
index 1e37313054f3..2743d82d4424 100644
--- a/drivers/net/can/cc770/cc770.c
+++ b/drivers/net/can/cc770/cc770.c
@@ -390,37 +390,23 @@ static int cc770_get_berr_counter(const struct net_device *dev,
return 0;
}
-static netdev_tx_t cc770_start_xmit(struct sk_buff *skb, struct net_device *dev)
+static void cc770_tx(struct net_device *dev, int mo)
{
struct cc770_priv *priv = netdev_priv(dev);
- struct net_device_stats *stats = &dev->stats;
- struct can_frame *cf = (struct can_frame *)skb->data;
- unsigned int mo = obj2msgobj(CC770_OBJ_TX);
+ struct can_frame *cf = (struct can_frame *)priv->tx_skb->data;
u8 dlc, rtr;
u32 id;
int i;
- if (can_dropped_invalid_skb(dev, skb))
- return NETDEV_TX_OK;
-
- if ((cc770_read_reg(priv,
- msgobj[mo].ctrl1) & TXRQST_UNC) == TXRQST_SET) {
- netdev_err(dev, "TX register is still occupied!\n");
- return NETDEV_TX_BUSY;
- }
-
- netif_stop_queue(dev);
-
dlc = cf->can_dlc;
id = cf->can_id;
- if (cf->can_id & CAN_RTR_FLAG)
- rtr = 0;
- else
- rtr = MSGCFG_DIR;
+ rtr = cf->can_id & CAN_RTR_FLAG ? 0 : MSGCFG_DIR;
+
+ cc770_write_reg(priv, msgobj[mo].ctrl0,
+ MSGVAL_RES | TXIE_RES | RXIE_RES | INTPND_RES);
cc770_write_reg(priv, msgobj[mo].ctrl1,
RMTPND_RES | TXRQST_RES | CPUUPD_SET | NEWDAT_RES);
- cc770_write_reg(priv, msgobj[mo].ctrl0,
- MSGVAL_SET | TXIE_SET | RXIE_RES | INTPND_RES);
+
if (id & CAN_EFF_FLAG) {
id &= CAN_EFF_MASK;
cc770_write_reg(priv, msgobj[mo].config,
@@ -439,22 +425,30 @@ static netdev_tx_t cc770_start_xmit(struct sk_buff *skb, struct net_device *dev)
for (i = 0; i < dlc; i++)
cc770_write_reg(priv, msgobj[mo].data[i], cf->data[i]);
- /* Store echo skb before starting the transfer */
- can_put_echo_skb(skb, dev, 0);
-
cc770_write_reg(priv, msgobj[mo].ctrl1,
- RMTPND_RES | TXRQST_SET | CPUUPD_RES | NEWDAT_UNC);
+ RMTPND_UNC | TXRQST_SET | CPUUPD_RES | NEWDAT_UNC);
+ cc770_write_reg(priv, msgobj[mo].ctrl0,
+ MSGVAL_SET | TXIE_SET | RXIE_SET | INTPND_UNC);
+}
- stats->tx_bytes += dlc;
+static netdev_tx_t cc770_start_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ struct cc770_priv *priv = netdev_priv(dev);
+ unsigned int mo = obj2msgobj(CC770_OBJ_TX);
+ if (can_dropped_invalid_skb(dev, skb))
+ return NETDEV_TX_OK;
- /*
- * HM: We had some cases of repeated IRQs so make sure the
- * INT is acknowledged I know it's already further up, but
- * doing again fixed the issue
- */
- cc770_write_reg(priv, msgobj[mo].ctrl0,
- MSGVAL_UNC | TXIE_UNC | RXIE_UNC | INTPND_RES);
+ netif_stop_queue(dev);
+
+ if ((cc770_read_reg(priv,
+ msgobj[mo].ctrl1) & TXRQST_UNC) == TXRQST_SET) {
+ netdev_err(dev, "TX register is still occupied!\n");
+ return NETDEV_TX_BUSY;
+ }
+
+ priv->tx_skb = skb;
+ cc770_tx(dev, mo);
return NETDEV_TX_OK;
}
@@ -680,19 +674,47 @@ static void cc770_tx_interrupt(struct net_device *dev, unsigned int o)
struct cc770_priv *priv = netdev_priv(dev);
struct net_device_stats *stats = &dev->stats;
unsigned int mo = obj2msgobj(o);
+ struct can_frame *cf;
+ u8 ctrl1;
+
+ ctrl1 = cc770_read_reg(priv, msgobj[mo].ctrl1);
- /* Nothing more to send, switch off interrupts */
cc770_write_reg(priv, msgobj[mo].ctrl0,
MSGVAL_RES | TXIE_RES | RXIE_RES | INTPND_RES);
- /*
- * We had some cases of repeated IRQ so make sure the
- * INT is acknowledged
+ cc770_write_reg(priv, msgobj[mo].ctrl1,
+ RMTPND_RES | TXRQST_RES | MSGLST_RES | NEWDAT_RES);
+
+ if (unlikely(!priv->tx_skb)) {
+ netdev_err(dev, "missing tx skb in tx interrupt\n");
+ return;
+ }
+
+ if (unlikely(ctrl1 & MSGLST_SET)) {
+ stats->rx_over_errors++;
+ stats->rx_errors++;
+ }
+
+ /* When the CC770 is sending an RTR message and it receives a regular
+ * message that matches the id of the RTR message, it will overwrite the
+ * outgoing message in the TX register. When this happens we must
+ * process the received message and try to transmit the outgoing skb
+ * again.
*/
- cc770_write_reg(priv, msgobj[mo].ctrl0,
- MSGVAL_UNC | TXIE_UNC | RXIE_UNC | INTPND_RES);
+ if (unlikely(ctrl1 & NEWDAT_SET)) {
+ cc770_rx(dev, mo, ctrl1);
+ cc770_tx(dev, mo);
+ return;
+ }
- stats->tx_packets++;
+ can_put_echo_skb(priv->tx_skb, dev, 0);
can_get_echo_skb(dev, 0);
+
+ cf = (struct can_frame *)priv->tx_skb->data;
+ stats->tx_bytes += cf->can_dlc;
+ stats->tx_packets++;
+
+ priv->tx_skb = NULL;
+
netif_wake_queue(dev);
}
@@ -804,6 +826,7 @@ struct net_device *alloc_cc770dev(int sizeof_priv)
priv->can.do_set_bittiming = cc770_set_bittiming;
priv->can.do_set_mode = cc770_set_mode;
priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
+ priv->tx_skb = NULL;
memcpy(priv->obj_flags, cc770_obj_flags, sizeof(cc770_obj_flags));
diff --git a/drivers/net/can/cc770/cc770.h b/drivers/net/can/cc770/cc770.h
index a1739db98d91..95752e1d1283 100644
--- a/drivers/net/can/cc770/cc770.h
+++ b/drivers/net/can/cc770/cc770.h
@@ -193,6 +193,8 @@ struct cc770_priv {
u8 cpu_interface; /* CPU interface register */
u8 clkout; /* Clock out register */
u8 bus_config; /* Bus conffiguration register */
+
+ struct sk_buff *tx_skb;
};
struct net_device *alloc_cc770dev(int sizeof_priv);