From: Thomas Gleixner Date: Tue, 18 Mar 2014 17:19:09 +0000 (+0000) Subject: can: c_can: Make it SMP safe X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=640916db2bf7de7c5ac13a1f470fa959459ccf6d;p=openwrt%2Fstaging%2Fblogic.git can: c_can: Make it SMP safe The hardware has two message control interfaces, but the code only uses the first one. So on SMP the following can be observed: CPU0 CPU1 rx_poll() write IF1 xmit() write IF1 write IF1 That results in corrupted message object configurations. The TX/RX is not globally serialized it's only serialized on a core. Simple solution: Let RX use IF1 and TX use IF2 and all is good. Signed-off-by: Thomas Gleixner Signed-off-by: Marc Kleine-Budde --- diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c index 4d08a32f27ac..38f9adaf15ac 100644 --- a/drivers/net/can/c_can/c_can.c +++ b/drivers/net/can/c_can/c_can.c @@ -132,6 +132,12 @@ #define IF_MCONT_EOB BIT(7) #define IF_MCONT_DLC_MASK 0xf +/* + * Use IF1 for RX and IF2 for TX + */ +#define IF_RX 0 +#define IF_TX 1 + /* * IFx register masks: * allow easy operation on 16-bit registers when the @@ -420,7 +426,7 @@ static void c_can_handle_lost_msg_obj(struct net_device *dev, priv->write_reg(priv, C_CAN_IFACE(MSGCTRL_REG, iface), IF_MCONT_CLR_MSGLST); - c_can_object_put(dev, 0, objno, IF_COMM_CONTROL); + c_can_object_put(dev, iface, objno, IF_COMM_CONTROL); /* create an error msg */ skb = alloc_can_err_skb(dev, &frame); @@ -551,7 +557,7 @@ static netdev_tx_t c_can_start_xmit(struct sk_buff *skb, msg_obj_no = get_tx_next_msg_obj(priv); /* prepare message object for transmission */ - c_can_write_msg_object(dev, 0, frame, msg_obj_no); + c_can_write_msg_object(dev, IF_TX, frame, msg_obj_no); can_put_echo_skb(skb, dev, msg_obj_no - C_CAN_MSG_OBJ_TX_FIRST); /* @@ -634,14 +640,14 @@ static void c_can_configure_msg_objects(struct net_device *dev) /* first invalidate all message objects */ for (i = C_CAN_MSG_OBJ_RX_FIRST; i <= C_CAN_NO_OF_OBJECTS; i++) - c_can_inval_msg_object(dev, 0, i); + c_can_inval_msg_object(dev, IF_RX, i); /* setup receive message objects */ for (i = C_CAN_MSG_OBJ_RX_FIRST; i < C_CAN_MSG_OBJ_RX_LAST; i++) - c_can_setup_receive_object(dev, 0, i, 0, 0, + c_can_setup_receive_object(dev, IF_RX, i, 0, 0, (IF_MCONT_RXIE | IF_MCONT_UMASK) & ~IF_MCONT_EOB); - c_can_setup_receive_object(dev, 0, C_CAN_MSG_OBJ_RX_LAST, 0, 0, + c_can_setup_receive_object(dev, IF_RX, C_CAN_MSG_OBJ_RX_LAST, 0, 0, IF_MCONT_EOB | IF_MCONT_RXIE | IF_MCONT_UMASK); } @@ -792,13 +798,13 @@ static void c_can_do_tx(struct net_device *dev) if (!(val & (1 << (msg_obj_no - 1)))) { can_get_echo_skb(dev, msg_obj_no - C_CAN_MSG_OBJ_TX_FIRST); - c_can_object_get(dev, 0, msg_obj_no, IF_COMM_ALL); + c_can_object_get(dev, IF_TX, msg_obj_no, IF_COMM_ALL); stats->tx_bytes += priv->read_reg(priv, - C_CAN_IFACE(MSGCTRL_REG, 0)) + C_CAN_IFACE(MSGCTRL_REG, IF_TX)) & IF_MCONT_DLC_MASK; stats->tx_packets++; can_led_event(dev, CAN_LED_EVENT_TX); - c_can_inval_msg_object(dev, 0, msg_obj_no); + c_can_inval_msg_object(dev, IF_TX, msg_obj_no); } else { break; } @@ -850,13 +856,13 @@ static int c_can_do_rx_poll(struct net_device *dev, int quota) while ((msg_obj = ffs(val)) && quota > 0) { val &= ~BIT(msg_obj - 1); - c_can_object_get(dev, 0, msg_obj, IF_COMM_ALL & + c_can_object_get(dev, IF_RX, msg_obj, IF_COMM_ALL & ~IF_COMM_TXRQST); msg_ctrl_save = priv->read_reg(priv, - C_CAN_IFACE(MSGCTRL_REG, 0)); + C_CAN_IFACE(MSGCTRL_REG, IF_RX)); if (msg_ctrl_save & IF_MCONT_MSGLST) { - c_can_handle_lost_msg_obj(dev, 0, msg_obj); + c_can_handle_lost_msg_obj(dev, IF_RX, msg_obj); num_rx_pkts++; quota--; continue; @@ -869,19 +875,19 @@ static int c_can_do_rx_poll(struct net_device *dev, int quota) continue; /* read the data from the message object */ - c_can_read_msg_object(dev, 0, msg_ctrl_save); + c_can_read_msg_object(dev, IF_RX, msg_ctrl_save); if (msg_obj < C_CAN_MSG_RX_LOW_LAST) - c_can_mark_rx_msg_obj(dev, 0, + c_can_mark_rx_msg_obj(dev, IF_RX, msg_ctrl_save, msg_obj); else if (msg_obj > C_CAN_MSG_RX_LOW_LAST) /* activate this msg obj */ - c_can_activate_rx_msg_obj(dev, 0, + c_can_activate_rx_msg_obj(dev, IF_RX, msg_ctrl_save, msg_obj); else if (msg_obj == C_CAN_MSG_RX_LOW_LAST) /* activate all lower message objects */ c_can_activate_all_lower_rx_msg_obj(dev, - 0, msg_ctrl_save); + IF_RX, msg_ctrl_save); num_rx_pkts++; quota--;