1 files changed, 282 insertions, 366 deletions

diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
index a5c8dcfa8357..95e04e2002da 100644
--- a/drivers/net/can/c_can/c_can.c
+++ b/drivers/net/can/c_can/c_can.c
@@ -60,6 +60,8 @@
 #define CONTROL_IE		BIT(1)
 #define CONTROL_INIT		BIT(0)
 
+#define CONTROL_IRQMSK		(CONTROL_EIE | CONTROL_IE | CONTROL_SIE)
+
 /* test register */
 #define TEST_RX			BIT(7)
 #define TEST_TX1		BIT(6)
@@ -108,11 +110,14 @@
 #define IF_COMM_CONTROL		BIT(4)
 #define IF_COMM_CLR_INT_PND	BIT(3)
 #define IF_COMM_TXRQST		BIT(2)
+#define IF_COMM_CLR_NEWDAT	IF_COMM_TXRQST
 #define IF_COMM_DATAA		BIT(1)
 #define IF_COMM_DATAB		BIT(0)
-#define IF_COMM_ALL		(IF_COMM_MASK | IF_COMM_ARB | \
-				IF_COMM_CONTROL | IF_COMM_TXRQST | \
-				IF_COMM_DATAA | IF_COMM_DATAB)
+
+/* TX buffer setup */
+#define IF_COMM_TX		(IF_COMM_ARB | IF_COMM_CONTROL | \
+				 IF_COMM_TXRQST |		 \
+				 IF_COMM_DATAA | IF_COMM_DATAB)
 
 /* For the low buffers we clear the interrupt bit, but keep newdat */
 #define IF_COMM_RCV_LOW		(IF_COMM_MASK | IF_COMM_ARB | \
@@ -120,12 +125,19 @@
 				 IF_COMM_DATAA | IF_COMM_DATAB)
 
 /* For the high buffers we clear the interrupt bit and newdat */
-#define IF_COMM_RCV_HIGH	(IF_COMM_RCV_LOW | IF_COMM_TXRQST)
+#define IF_COMM_RCV_HIGH	(IF_COMM_RCV_LOW | IF_COMM_CLR_NEWDAT)
+
+
+/* Receive setup of message objects */
+#define IF_COMM_RCV_SETUP	(IF_COMM_MASK | IF_COMM_ARB | IF_COMM_CONTROL)
+
+/* Invalidation of message objects */
+#define IF_COMM_INVAL		(IF_COMM_ARB | IF_COMM_CONTROL)
 
 /* IFx arbitration */
-#define IF_ARB_MSGVAL		BIT(15)
-#define IF_ARB_MSGXTD		BIT(14)
-#define IF_ARB_TRANSMIT		BIT(13)
+#define IF_ARB_MSGVAL		BIT(31)
+#define IF_ARB_MSGXTD		BIT(30)
+#define IF_ARB_TRANSMIT		BIT(29)
 
 /* IFx message control */
 #define IF_MCONT_NEWDAT		BIT(15)
@@ -139,19 +151,17 @@
 #define IF_MCONT_EOB		BIT(7)
 #define IF_MCONT_DLC_MASK	0xf
 
+#define IF_MCONT_RCV		(IF_MCONT_RXIE | IF_MCONT_UMASK)
+#define IF_MCONT_RCV_EOB	(IF_MCONT_RCV | IF_MCONT_EOB)
+
+#define IF_MCONT_TX		(IF_MCONT_TXIE | IF_MCONT_EOB)
+
 /*
  * Use IF1 for RX and IF2 for TX
  */
 #define IF_RX			0
 #define IF_TX			1
 
-/* status interrupt */
-#define STATUS_INTERRUPT	0x8000
-
-/* global interrupt masks */
-#define ENABLE_ALL_INTERRUPTS	1
-#define DISABLE_ALL_INTERRUPTS	0
-
 /* minimum timeout for checking BUSY status */
 #define MIN_TIMEOUT_VALUE	6
 
@@ -171,6 +181,7 @@ enum c_can_lec_type {
 	LEC_BIT0_ERROR,
 	LEC_CRC_ERROR,
 	LEC_UNUSED,
+	LEC_MASK = LEC_UNUSED,
 };
 
 /*
@@ -226,143 +237,115 @@ static inline void c_can_reset_ram(const struct c_can_priv *priv, bool enable)
 		priv->raminit(priv, enable);
 }
 
-static inline int get_tx_next_msg_obj(const struct c_can_priv *priv)
-{
-	return (priv->tx_next & C_CAN_NEXT_MSG_OBJ_MASK) +
-			C_CAN_MSG_OBJ_TX_FIRST;
-}
-
-static inline int get_tx_echo_msg_obj(int txecho)
-{
-	return (txecho & C_CAN_NEXT_MSG_OBJ_MASK) + C_CAN_MSG_OBJ_TX_FIRST;
-}
-
-static u32 c_can_read_reg32(struct c_can_priv *priv, enum reg index)
-{
-	u32 val = priv->read_reg(priv, index);
-	val |= ((u32) priv->read_reg(priv, index + 1)) << 16;
-	return val;
-}
-
-static void c_can_enable_all_interrupts(struct c_can_priv *priv,
-						int enable)
+static void c_can_irq_control(struct c_can_priv *priv, bool enable)
 {
-	unsigned int cntrl_save = priv->read_reg(priv,
-						C_CAN_CTRL_REG);
+	u32 ctrl = priv->read_reg(priv,	C_CAN_CTRL_REG) & ~CONTROL_IRQMSK;
 
 	if (enable)
-		cntrl_save |= (CONTROL_SIE | CONTROL_EIE | CONTROL_IE);
-	else
-		cntrl_save &= ~(CONTROL_EIE | CONTROL_IE | CONTROL_SIE);
+		ctrl |= CONTROL_IRQMSK;
 
-	priv->write_reg(priv, C_CAN_CTRL_REG, cntrl_save);
+	priv->write_reg(priv, C_CAN_CTRL_REG, ctrl);
 }
 
-static inline int c_can_msg_obj_is_busy(struct c_can_priv *priv, int iface)
+static void c_can_obj_update(struct net_device *dev, int iface, u32 cmd, u32 obj)
 {
-	int count = MIN_TIMEOUT_VALUE;
+	struct c_can_priv *priv = netdev_priv(dev);
+	int cnt, reg = C_CAN_IFACE(COMREQ_REG, iface);
 
-	while (count && priv->read_reg(priv,
-				C_CAN_IFACE(COMREQ_REG, iface)) &
-				IF_COMR_BUSY) {
-		count--;
+	priv->write_reg(priv, reg + 1, cmd);
+	priv->write_reg(priv, reg, obj);
+
+	for (cnt = MIN_TIMEOUT_VALUE; cnt; cnt--) {
+		if (!(priv->read_reg(priv, reg) & IF_COMR_BUSY))
+			return;
 		udelay(1);
 	}
+	netdev_err(dev, "Updating object timed out\n");
 
-	if (!count)
-		return 1;
+}
 
-	return 0;
+static inline void c_can_object_get(struct net_device *dev, int iface,
+				    u32 obj, u32 cmd)
+{
+	c_can_obj_update(dev, iface, cmd, obj);
 }
 
-static inline void c_can_object_get(struct net_device *dev,
-					int iface, int objno, int mask)
+static inline void c_can_object_put(struct net_device *dev, int iface,
+				    u32 obj, u32 cmd)
 {
-	struct c_can_priv *priv = netdev_priv(dev);
+	c_can_obj_update(dev, iface, cmd | IF_COMM_WR, obj);
+}
 
-	/*
-	 * As per specs, after writting the message object number in the
-	 * IF command request register the transfer b/w interface
-	 * register and message RAM must be complete in 6 CAN-CLK
-	 * period.
-	 */
-	priv->write_reg(priv, C_CAN_IFACE(COMMSK_REG, iface),
-			IFX_WRITE_LOW_16BIT(mask));
-	priv->write_reg(priv, C_CAN_IFACE(COMREQ_REG, iface),
-			IFX_WRITE_LOW_16BIT(objno));
+/*
+ * Note: According to documentation clearing TXIE while MSGVAL is set
+ * is not allowed, but works nicely on C/DCAN. And that lowers the I/O
+ * load significantly.
+ */
+static void c_can_inval_tx_object(struct net_device *dev, int iface, int obj)
+{
+	struct c_can_priv *priv = netdev_priv(dev);
 
-	if (c_can_msg_obj_is_busy(priv, iface))
-		netdev_err(dev, "timed out in object get\n");
+	priv->write_reg(priv, C_CAN_IFACE(MSGCTRL_REG, iface), 0);
+	c_can_object_put(dev, iface, obj, IF_COMM_INVAL);
 }
 
-static inline void c_can_object_put(struct net_device *dev,
-					int iface, int objno, int mask)
+static void c_can_inval_msg_object(struct net_device *dev, int iface, int obj)
 {
 	struct c_can_priv *priv = netdev_priv(dev);
 
-	/*
-	 * As per specs, after writting the message object number in the
-	 * IF command request register the transfer b/w interface
-	 * register and message RAM must be complete in 6 CAN-CLK
-	 * period.
-	 */
-	priv->write_reg(priv, C_CAN_IFACE(COMMSK_REG, iface),
-			(IF_COMM_WR | IFX_WRITE_LOW_16BIT(mask)));
-	priv->write_reg(priv, C_CAN_IFACE(COMREQ_REG, iface),
-			IFX_WRITE_LOW_16BIT(objno));
-
-	if (c_can_msg_obj_is_busy(priv, iface))
-		netdev_err(dev, "timed out in object put\n");
+	priv->write_reg(priv, C_CAN_IFACE(ARB1_REG, iface), 0);
+	priv->write_reg(priv, C_CAN_IFACE(ARB2_REG, iface), 0);
+	c_can_inval_tx_object(dev, iface, obj);
 }
 
-static void c_can_write_msg_object(struct net_device *dev,
-			int iface, struct can_frame *frame, int objno)
+static void c_can_setup_tx_object(struct net_device *dev, int iface,
+				  struct can_frame *frame, int idx)
 {
-	int i;
-	u16 flags = 0;
-	unsigned int id;
 	struct c_can_priv *priv = netdev_priv(dev);
-
-	if (!(frame->can_id & CAN_RTR_FLAG))
-		flags |= IF_ARB_TRANSMIT;
+	u16 ctrl = IF_MCONT_TX | frame->can_dlc;
+	bool rtr = frame->can_id & CAN_RTR_FLAG;
+	u32 arb = IF_ARB_MSGVAL;
+	int i;
 
 	if (frame->can_id & CAN_EFF_FLAG) {
-		id = frame->can_id & CAN_EFF_MASK;
-		flags |= IF_ARB_MSGXTD;
-	} else
-		id = ((frame->can_id & CAN_SFF_MASK) << 18);
+		arb |= frame->can_id & CAN_EFF_MASK;
+		arb |= IF_ARB_MSGXTD;
+	} else {
+		arb |= (frame->can_id & CAN_SFF_MASK) << 18;
+	}
+
+	if (!rtr)
+		arb |= IF_ARB_TRANSMIT;
+
+	/*
+	 * If we change the DIR bit, we need to invalidate the buffer
+	 * first, i.e. clear the MSGVAL flag in the arbiter.
+	 */
+	if (rtr != (bool)test_bit(idx, &priv->tx_dir)) {
+		u32 obj = idx + C_CAN_MSG_OBJ_TX_FIRST;
+
+		c_can_inval_msg_object(dev, iface, obj);
+		change_bit(idx, &priv->tx_dir);
+	}
 
-	flags |= IF_ARB_MSGVAL;
+	priv->write_reg(priv, C_CAN_IFACE(ARB1_REG, iface), arb);
+	priv->write_reg(priv, C_CAN_IFACE(ARB2_REG, iface), arb >> 16);
 
-	priv->write_reg(priv, C_CAN_IFACE(ARB1_REG, iface),
-				IFX_WRITE_LOW_16BIT(id));
-	priv->write_reg(priv, C_CAN_IFACE(ARB2_REG, iface), flags |
-				IFX_WRITE_HIGH_16BIT(id));
+	priv->write_reg(priv, C_CAN_IFACE(MSGCTRL_REG, iface), ctrl);
 
 	for (i = 0; i < frame->can_dlc; i += 2) {
 		priv->write_reg(priv, C_CAN_IFACE(DATA1_REG, iface) + i / 2,
 				frame->data[i] | (frame->data[i + 1] << 8));
 	}
-
-	/* enable interrupt for this message object */
-	priv->write_reg(priv, C_CAN_IFACE(MSGCTRL_REG, iface),
-			IF_MCONT_TXIE | IF_MCONT_TXRQST | IF_MCONT_EOB |
-			frame->can_dlc);
-	c_can_object_put(dev, iface, objno, IF_COMM_ALL);
 }
 
 static inline void c_can_activate_all_lower_rx_msg_obj(struct net_device *dev,
-						int iface,
-						int ctrl_mask)
+						       int iface)
 {
 	int i;
-	struct c_can_priv *priv = netdev_priv(dev);
 
-	for (i = C_CAN_MSG_OBJ_RX_FIRST; i <= C_CAN_MSG_RX_LOW_LAST; i++) {
-		priv->write_reg(priv, C_CAN_IFACE(MSGCTRL_REG, iface),
-				ctrl_mask & ~IF_MCONT_NEWDAT);
-		c_can_object_put(dev, iface, i, IF_COMM_CONTROL);
-	}
+	for (i = C_CAN_MSG_OBJ_RX_FIRST; i <= C_CAN_MSG_RX_LOW_LAST; i++)
+		c_can_object_get(dev, iface, i, IF_COMM_CLR_NEWDAT);
 }
 
 static int c_can_handle_lost_msg_obj(struct net_device *dev,
@@ -377,6 +360,9 @@ static int c_can_handle_lost_msg_obj(struct net_device *dev,
 	priv->write_reg(priv, C_CAN_IFACE(MSGCTRL_REG, iface), ctrl);
 	c_can_object_put(dev, iface, objno, IF_COMM_CONTROL);
 
+	stats->rx_errors++;
+	stats->rx_over_errors++;
+
 	/* create an error msg */
 	skb = alloc_can_err_skb(dev, &frame);
 	if (unlikely(!skb))
@@ -384,22 +370,18 @@ static int c_can_handle_lost_msg_obj(struct net_device *dev,
 
 	frame->can_id |= CAN_ERR_CRTL;
 	frame->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
-	stats->rx_errors++;
-	stats->rx_over_errors++;
 
 	netif_receive_skb(skb);
 	return 1;
 }
 
-static int c_can_read_msg_object(struct net_device *dev, int iface, int ctrl)
+static int c_can_read_msg_object(struct net_device *dev, int iface, u32 ctrl)
 {
-	u16 flags, data;
-	int i;
-	unsigned int val;
-	struct c_can_priv *priv = netdev_priv(dev);
 	struct net_device_stats *stats = &dev->stats;
-	struct sk_buff *skb;
+	struct c_can_priv *priv = netdev_priv(dev);
 	struct can_frame *frame;
+	struct sk_buff *skb;
+	u32 arb, data;
 
 	skb = alloc_can_skb(dev, &frame);
 	if (!skb) {
@@ -409,115 +391,82 @@ static int c_can_read_msg_object(struct net_device *dev, int iface, int ctrl)
 
 	frame->can_dlc = get_can_dlc(ctrl & 0x0F);
 
-	flags =	priv->read_reg(priv, C_CAN_IFACE(ARB2_REG, iface));
-	val = priv->read_reg(priv, C_CAN_IFACE(ARB1_REG, iface)) |
-		(flags << 16);
+	arb = priv->read_reg(priv, C_CAN_IFACE(ARB1_REG, iface));
+	arb |= priv->read_reg(priv, C_CAN_IFACE(ARB2_REG, iface)) << 16;
 
-	if (flags & IF_ARB_MSGXTD)
-		frame->can_id = (val & CAN_EFF_MASK) | CAN_EFF_FLAG;
+	if (arb & IF_ARB_MSGXTD)
+		frame->can_id = (arb & CAN_EFF_MASK) | CAN_EFF_FLAG;
 	else
-		frame->can_id = (val >> 18) & CAN_SFF_MASK;
+		frame->can_id = (arb >> 18) & CAN_SFF_MASK;
 
-	if (flags & IF_ARB_TRANSMIT)
+	if (arb & IF_ARB_TRANSMIT) {
 		frame->can_id |= CAN_RTR_FLAG;
-	else {
-		for (i = 0; i < frame->can_dlc; i += 2) {
-			data = priv->read_reg(priv,
-				C_CAN_IFACE(DATA1_REG, iface) + i / 2);
+	} else {
+		int i, dreg = C_CAN_IFACE(DATA1_REG, iface);
+
+		for (i = 0; i < frame->can_dlc; i += 2, dreg ++) {
+			data = priv->read_reg(priv, dreg);
 			frame->data[i] = data;
 			frame->data[i + 1] = data >> 8;
 		}
 	}
 
-	netif_receive_skb(skb);
-
 	stats->rx_packets++;
 	stats->rx_bytes += frame->can_dlc;
+
+	netif_receive_skb(skb);
 	return 0;
 }
 
 static void c_can_setup_receive_object(struct net_device *dev, int iface,
-					int objno, unsigned int mask,
-					unsigned int id, unsigned int mcont)
+				       u32 obj, u32 mask, u32 id, u32 mcont)
 {
 	struct c_can_priv *priv = netdev_priv(dev);
 
-	priv->write_reg(priv, C_CAN_IFACE(MASK1_REG, iface),
-			IFX_WRITE_LOW_16BIT(mask));
-
-	/* According to C_CAN documentation, the reserved bit
-	 * in IFx_MASK2 register is fixed 1
-	 */
-	priv->write_reg(priv, C_CAN_IFACE(MASK2_REG, iface),
-			IFX_WRITE_HIGH_16BIT(mask) | BIT(13));
+	mask |= BIT(29);
+	priv->write_reg(priv, C_CAN_IFACE(MASK1_REG, iface), mask);
+	priv->write_reg(priv, C_CAN_IFACE(MASK2_REG, iface), mask >> 16);
 
-	priv->write_reg(priv, C_CAN_IFACE(ARB1_REG, iface),
-			IFX_WRITE_LOW_16BIT(id));
-	priv->write_reg(priv, C_CAN_IFACE(ARB2_REG, iface),
-			(IF_ARB_MSGVAL | IFX_WRITE_HIGH_16BIT(id)));
+	id |= IF_ARB_MSGVAL;
+	priv->write_reg(priv, C_CAN_IFACE(ARB1_REG, iface), id);
+	priv->write_reg(priv, C_CAN_IFACE(ARB2_REG, iface), id >> 16);
 
 	priv->write_reg(priv, C_CAN_IFACE(MSGCTRL_REG, iface), mcont);
-	c_can_object_put(dev, iface, objno, IF_COMM_ALL & ~IF_COMM_TXRQST);
-
-	netdev_dbg(dev, "obj no:%d, msgval:0x%08x\n", objno,
-			c_can_read_reg32(priv, C_CAN_MSGVAL1_REG));
-}
-
-static void c_can_inval_msg_object(struct net_device *dev, int iface, int objno)
-{
-	struct c_can_priv *priv = netdev_priv(dev);
-
-	priv->write_reg(priv, C_CAN_IFACE(ARB1_REG, iface), 0);
-	priv->write_reg(priv, C_CAN_IFACE(ARB2_REG, iface), 0);
-	priv->write_reg(priv, C_CAN_IFACE(MSGCTRL_REG, iface), 0);
-
-	c_can_object_put(dev, iface, objno, IF_COMM_ARB | IF_COMM_CONTROL);
-
-	netdev_dbg(dev, "obj no:%d, msgval:0x%08x\n", objno,
-			c_can_read_reg32(priv, C_CAN_MSGVAL1_REG));
-}
-
-static inline int c_can_is_next_tx_obj_busy(struct c_can_priv *priv, int objno)
-{
-	int val = c_can_read_reg32(priv, C_CAN_TXRQST1_REG);
-
-	/*
-	 * as transmission request register's bit n-1 corresponds to
-	 * message object n, we need to handle the same properly.
-	 */
-	if (val & (1 << (objno - 1)))
-		return 1;
-
-	return 0;
+	c_can_object_put(dev, iface, obj, IF_COMM_RCV_SETUP);
 }
 
 static netdev_tx_t c_can_start_xmit(struct sk_buff *skb,
-					struct net_device *dev)
+				    struct net_device *dev)
 {
-	u32 msg_obj_no;
-	struct c_can_priv *priv = netdev_priv(dev);
 	struct can_frame *frame = (struct can_frame *)skb->data;
+	struct c_can_priv *priv = netdev_priv(dev);
+	u32 idx, obj;
 
 	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 */
-	c_can_write_msg_object(dev, IF_TX, frame, msg_obj_no);
-	priv->dlc[msg_obj_no - C_CAN_MSG_OBJ_TX_FIRST] = frame->can_dlc;
-	can_put_echo_skb(skb, dev, msg_obj_no - C_CAN_MSG_OBJ_TX_FIRST);
-
 	/*
-	 * we have to stop the queue in case of a wrap around or
-	 * if the next TX message object is still in use
+	 * This is not a FIFO. C/D_CAN sends out the buffers
+	 * prioritized. The lowest buffer number wins.
 	 */
-	priv->tx_next++;
-	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)
+	idx = fls(atomic_read(&priv->tx_active));
+	obj = idx + C_CAN_MSG_OBJ_TX_FIRST;
+
+	/* If this is the last buffer, stop the xmit queue */
+	if (idx == C_CAN_MSG_OBJ_TX_NUM - 1)
 		netif_stop_queue(dev);
-	spin_unlock_bh(&priv->xmit_lock);
+	/*
+	 * Store the message in the interface so we can call
+	 * can_put_echo_skb(). We must do this before we enable
+	 * transmit as we might race against do_tx().
+	 */
+	c_can_setup_tx_object(dev, IF_TX, frame, idx);
+	priv->dlc[idx] = frame->can_dlc;
+	can_put_echo_skb(skb, dev, idx);
+
+	/* Update the active bits */
+	atomic_add((1 << idx), &priv->tx_active);
+	/* Start transmission */
+	c_can_object_put(dev, IF_TX, obj, IF_COMM_TX);
 
 	return NETDEV_TX_OK;
 }
@@ -594,11 +543,10 @@ static void c_can_configure_msg_objects(struct net_device *dev)
 
 	/* 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, IF_RX, i, 0, 0,
-			(IF_MCONT_RXIE | IF_MCONT_UMASK) & ~IF_MCONT_EOB);
+		c_can_setup_receive_object(dev, IF_RX, i, 0, 0, IF_MCONT_RCV);
 
 	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);
+				   IF_MCONT_RCV_EOB);
 }
 
 /*
@@ -612,30 +560,22 @@ static int c_can_chip_config(struct net_device *dev)
 	struct c_can_priv *priv = netdev_priv(dev);
 
 	/* enable automatic retransmission */
-	priv->write_reg(priv, C_CAN_CTRL_REG,
-			CONTROL_ENABLE_AR);
+	priv->write_reg(priv, C_CAN_CTRL_REG, CONTROL_ENABLE_AR);
 
 	if ((priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY) &&
 	    (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)) {
 		/* loopback + silent mode : useful for hot self-test */
-		priv->write_reg(priv, C_CAN_CTRL_REG, CONTROL_EIE |
-				CONTROL_SIE | CONTROL_IE | CONTROL_TEST);
-		priv->write_reg(priv, C_CAN_TEST_REG,
-				TEST_LBACK | TEST_SILENT);
+		priv->write_reg(priv, C_CAN_CTRL_REG, CONTROL_TEST);
+		priv->write_reg(priv, C_CAN_TEST_REG, TEST_LBACK | TEST_SILENT);
 	} else if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) {
 		/* loopback mode : useful for self-test function */
-		priv->write_reg(priv, C_CAN_CTRL_REG, CONTROL_EIE |
-				CONTROL_SIE | CONTROL_IE | CONTROL_TEST);
+		priv->write_reg(priv, C_CAN_CTRL_REG, CONTROL_TEST);
 		priv->write_reg(priv, C_CAN_TEST_REG, TEST_LBACK);
 	} else if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY) {
 		/* silent mode : bus-monitoring mode */
-		priv->write_reg(priv, C_CAN_CTRL_REG, CONTROL_EIE |
-				CONTROL_SIE | CONTROL_IE | CONTROL_TEST);
+		priv->write_reg(priv, C_CAN_CTRL_REG, CONTROL_TEST);
 		priv->write_reg(priv, C_CAN_TEST_REG, TEST_SILENT);
-	} else
-		/* normal mode*/
-		priv->write_reg(priv, C_CAN_CTRL_REG,
-				CONTROL_EIE | CONTROL_SIE | CONTROL_IE);
+	}
 
 	/* configure message objects */
 	c_can_configure_msg_objects(dev);
@@ -643,6 +583,11 @@ static int c_can_chip_config(struct net_device *dev)
 	/* set a `lec` value so that we can check for updates later */
 	priv->write_reg(priv, C_CAN_STS_REG, LEC_UNUSED);
 
+	/* Clear all internal status */
+	atomic_set(&priv->tx_active, 0);
+	priv->rxmasked = 0;
+	priv->tx_dir = 0;
+
 	/* set bittiming params */
 	return c_can_set_bittiming(dev);
 }
@@ -657,13 +602,11 @@ static int c_can_start(struct net_device *dev)
 	if (err)
 		return err;
 
-	priv->can.state = CAN_STATE_ERROR_ACTIVE;
-
-	/* reset tx helper pointers */
-	priv->tx_next = priv->tx_echo = 0;
+	/* Setup the command for new messages */
+	priv->comm_rcv_high = priv->type != BOSCH_D_CAN ?
+		IF_COMM_RCV_LOW : IF_COMM_RCV_HIGH;
 
-	/* enable status change, error and module interrupts */
-	c_can_enable_all_interrupts(priv, ENABLE_ALL_INTERRUPTS);
+	priv->can.state = CAN_STATE_ERROR_ACTIVE;
 
 	return 0;
 }
@@ -672,15 +615,13 @@ static void c_can_stop(struct net_device *dev)
 {
 	struct c_can_priv *priv = netdev_priv(dev);
 
-	/* disable all interrupts */
-	c_can_enable_all_interrupts(priv, DISABLE_ALL_INTERRUPTS);
-
-	/* set the state as STOPPED */
+	c_can_irq_control(priv, false);
 	priv->can.state = CAN_STATE_STOPPED;
 }
 
 static int c_can_set_mode(struct net_device *dev, enum can_mode mode)
 {
+	struct c_can_priv *priv = netdev_priv(dev);
 	int err;
 
 	switch (mode) {
@@ -689,6 +630,7 @@ static int c_can_set_mode(struct net_device *dev, enum can_mode mode)
 		if (err)
 			return err;
 		netif_wake_queue(dev);
+		c_can_irq_control(priv, true);
 		break;
 	default:
 		return -EOPNOTSUPP;
@@ -724,42 +666,29 @@ static int c_can_get_berr_counter(const struct net_device *dev,
 	return err;
 }
 
-/*
- * priv->tx_echo holds the number of the oldest can_frame put for
- * transmission into the hardware, but not yet ACKed by the CAN tx
- * complete IRQ.
- *
- * We iterate from priv->tx_echo to priv->tx_next and check if the
- * packet has been transmitted, echo it back to the CAN framework.
- * If we discover a not yet transmitted packet, stop looking for more.
- */
 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;
-	u32 val, obj, pkts = 0, bytes = 0;
-
-	spin_lock_bh(&priv->xmit_lock);
-
-	for (; (priv->tx_next - priv->tx_echo) > 0; priv->tx_echo++) {
-		obj = get_tx_echo_msg_obj(priv->tx_echo);
-		val = c_can_read_reg32(priv, C_CAN_TXRQST1_REG);
+	u32 idx, obj, pkts = 0, bytes = 0, pend, clr;
 
-		if (val & (1 << (obj - 1)))
-			break;
+	clr = pend = priv->read_reg(priv, C_CAN_INTPND2_REG);
 
-		can_get_echo_skb(dev, obj - C_CAN_MSG_OBJ_TX_FIRST);
-		bytes += priv->dlc[obj - C_CAN_MSG_OBJ_TX_FIRST];
+	while ((idx = ffs(pend))) {
+		idx--;
+		pend &= ~(1 << idx);
+		obj = idx + C_CAN_MSG_OBJ_TX_FIRST;
+		c_can_inval_tx_object(dev, IF_RX, obj);
+		can_get_echo_skb(dev, idx);
+		bytes += priv->dlc[idx];
 		pkts++;
-		c_can_inval_msg_object(dev, IF_TX, obj);
 	}
 
-	/* restart queue if wrap-up or if queue stalled on last pkt */
-	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);
+	/* Clear the bits in the tx_active mask */
+	atomic_sub(clr, &priv->tx_active);
 
-	spin_unlock_bh(&priv->xmit_lock);
+	if (clr & (1 << (C_CAN_MSG_OBJ_TX_NUM - 1)))
+		netif_wake_queue(dev);
 
 	if (pkts) {
 		stats->tx_bytes += bytes;
@@ -800,18 +729,28 @@ static u32 c_can_adjust_pending(u32 pend)
 	return pend & ~((1 << lasts) - 1);
 }
 
+static inline void c_can_rx_object_get(struct net_device *dev,
+				       struct c_can_priv *priv, u32 obj)
+{
+		c_can_object_get(dev, IF_RX, obj, priv->comm_rcv_high);
+}
+
+static inline void c_can_rx_finalize(struct net_device *dev,
+				     struct c_can_priv *priv, u32 obj)
+{
+	if (priv->type != BOSCH_D_CAN)
+		c_can_object_get(dev, IF_RX, obj, IF_COMM_CLR_NEWDAT);
+}
+
 static int c_can_read_objects(struct net_device *dev, struct c_can_priv *priv,
 			      u32 pend, int quota)
 {
-	u32 pkts = 0, ctrl, obj, mcmd;
+	u32 pkts = 0, ctrl, obj;
 
 	while ((obj = ffs(pend)) && quota > 0) {
 		pend &= ~BIT(obj - 1);
 
-		mcmd = obj < C_CAN_MSG_RX_LOW_LAST ?
-			IF_COMM_RCV_LOW : IF_COMM_RCV_HIGH;
-
-		c_can_object_get(dev, IF_RX, obj, mcmd);
+		c_can_rx_object_get(dev, priv, obj);
 		ctrl = priv->read_reg(priv, C_CAN_IFACE(MSGCTRL_REG, IF_RX));
 
 		if (ctrl & IF_MCONT_MSGLST) {
@@ -833,9 +772,7 @@ static int c_can_read_objects(struct net_device *dev, struct c_can_priv *priv,
 		/* read the data from the message object */
 		c_can_read_msg_object(dev, IF_RX, ctrl);
 
-		if (obj == C_CAN_MSG_RX_LOW_LAST)
-			/* activate all lower message objects */
-			c_can_activate_all_lower_rx_msg_obj(dev, IF_RX, ctrl);
+		c_can_rx_finalize(dev, priv, obj);
 
 		pkts++;
 		quota--;
@@ -844,6 +781,13 @@ static int c_can_read_objects(struct net_device *dev, struct c_can_priv *priv,
 	return pkts;
 }
 
+static inline u32 c_can_get_pending(struct c_can_priv *priv)
+{
+	u32 pend = priv->read_reg(priv, C_CAN_NEWDAT1_REG);
+
+	return pend;
+}
+
 /*
  * theory of operation:
  *
@@ -853,18 +797,9 @@ static int c_can_read_objects(struct net_device *dev, struct c_can_priv *priv,
  * has arrived. To work-around this issue, we keep two groups of message
  * objects whose partitioning is defined by C_CAN_MSG_OBJ_RX_SPLIT.
  *
- * To ensure in-order frame reception we use the following
- * approach while re-activating a message object to receive further
- * frames:
- * - if the current message object number is lower than
- *   C_CAN_MSG_RX_LOW_LAST, do not clear the NEWDAT bit while clearing
- *   the INTPND bit.
- * - if the current message object number is equal to
- *   C_CAN_MSG_RX_LOW_LAST then clear the NEWDAT bit of all lower
- *   receive message objects.
- * - if the current message object number is greater than
- *   C_CAN_MSG_RX_LOW_LAST then clear the NEWDAT bit of
- *   only this message object.
+ * We clear the newdat bit right away.
+ *
+ * This can result in packet reordering when the readout is slow.
  */
 static int c_can_do_rx_poll(struct net_device *dev, int quota)
 {
@@ -880,7 +815,7 @@ static int c_can_do_rx_poll(struct net_device *dev, int quota)
 
 	while (quota > 0) {
 		if (!pend) {
-			pend = priv->read_reg(priv, C_CAN_INTPND1_REG);
+			pend = c_can_get_pending(priv);
 			if (!pend)
 				break;
 			/*
@@ -905,12 +840,6 @@ static int c_can_do_rx_poll(struct net_device *dev, int quota)
 	return pkts;
 }
 
-static inline int c_can_has_and_handle_berr(struct c_can_priv *priv)
-{
-	return (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) &&
-		(priv->current_status & LEC_UNUSED);
-}
-
 static int c_can_handle_state_change(struct net_device *dev,
 				enum c_can_bus_error_types error_type)
 {
@@ -922,6 +851,26 @@ static int c_can_handle_state_change(struct net_device *dev,
 	struct sk_buff *skb;
 	struct can_berr_counter bec;
 
+	switch (error_type) {
+	case C_CAN_ERROR_WARNING:
+		/* error warning state */
+		priv->can.can_stats.error_warning++;
+		priv->can.state = CAN_STATE_ERROR_WARNING;
+		break;
+	case C_CAN_ERROR_PASSIVE:
+		/* error passive state */
+		priv->can.can_stats.error_passive++;
+		priv->can.state = CAN_STATE_ERROR_PASSIVE;
+		break;
+	case C_CAN_BUS_OFF:
+		/* bus-off state */
+		priv->can.state = CAN_STATE_BUS_OFF;
+		can_bus_off(dev);
+		break;
+	default:
+		break;
+	}
+
 	/* propagate the error condition to the CAN stack */
 	skb = alloc_can_err_skb(dev, &cf);
 	if (unlikely(!skb))
@@ -935,8 +884,6 @@ static int c_can_handle_state_change(struct net_device *dev,
 	switch (error_type) {
 	case C_CAN_ERROR_WARNING:
 		/* error warning state */
-		priv->can.can_stats.error_warning++;
-		priv->can.state = CAN_STATE_ERROR_WARNING;
 		cf->can_id |= CAN_ERR_CRTL;
 		cf->data[1] = (bec.txerr > bec.rxerr) ?
 			CAN_ERR_CRTL_TX_WARNING :
@@ -947,8 +894,6 @@ static int c_can_handle_state_change(struct net_device *dev,
 		break;
 	case C_CAN_ERROR_PASSIVE:
 		/* error passive state */
-		priv->can.can_stats.error_passive++;
-		priv->can.state = CAN_STATE_ERROR_PASSIVE;
 		cf->can_id |= CAN_ERR_CRTL;
 		if (rx_err_passive)
 			cf->data[1] |= CAN_ERR_CRTL_RX_PASSIVE;
@@ -960,22 +905,16 @@ static int c_can_handle_state_change(struct net_device *dev,
 		break;
 	case C_CAN_BUS_OFF:
 		/* bus-off state */
-		priv->can.state = CAN_STATE_BUS_OFF;
 		cf->can_id |= CAN_ERR_BUSOFF;
-		/*
-		 * disable all interrupts in bus-off mode to ensure that
-		 * the CPU is not hogged down
-		 */
-		c_can_enable_all_interrupts(priv, DISABLE_ALL_INTERRUPTS);
 		can_bus_off(dev);
 		break;
 	default:
 		break;
 	}
 
-	netif_receive_skb(skb);
 	stats->rx_packets++;
 	stats->rx_bytes += cf->can_dlc;
+	netif_receive_skb(skb);
 
 	return 1;
 }
@@ -996,6 +935,13 @@ static int c_can_handle_bus_err(struct net_device *dev,
 	if (lec_type == LEC_UNUSED || lec_type == LEC_NO_ERROR)
 		return 0;
 
+	if (!(priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING))
+		return 0;
+
+	/* common for all type of bus errors */
+	priv->can.can_stats.bus_error++;
+	stats->rx_errors++;
+
 	/* propagate the error condition to the CAN stack */
 	skb = alloc_can_err_skb(dev, &cf);
 	if (unlikely(!skb))
@@ -1005,10 +951,6 @@ static int c_can_handle_bus_err(struct net_device *dev,
 	 * check for 'last error code' which tells us the
 	 * type of the last error to occur on the CAN bus
 	 */
-
-	/* common for all type of bus errors */
-	priv->can.can_stats.bus_error++;
-	stats->rx_errors++;
 	cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
 	cf->data[2] |= CAN_ERR_PROT_UNSPEC;
 
@@ -1043,95 +985,64 @@ static int c_can_handle_bus_err(struct net_device *dev,
 		break;
 	}
 
-	/* set a `lec` value so that we can check for updates later */
-	priv->write_reg(priv, C_CAN_STS_REG, LEC_UNUSED);
-
-	netif_receive_skb(skb);
 	stats->rx_packets++;
 	stats->rx_bytes += cf->can_dlc;
-
+	netif_receive_skb(skb);
 	return 1;
 }
 
 static int c_can_poll(struct napi_struct *napi, int quota)
 {
-	u16 irqstatus;
-	int lec_type = 0;
-	int work_done = 0;
 	struct net_device *dev = napi->dev;
 	struct c_can_priv *priv = netdev_priv(dev);
+	u16 curr, last = priv->last_status;
+	int work_done = 0;
 
-	irqstatus = priv->irqstatus;
-	if (!irqstatus)
-		goto end;
+	priv->last_status = curr = priv->read_reg(priv, C_CAN_STS_REG);
+	/* Ack status on C_CAN. D_CAN is self clearing */
+	if (priv->type != BOSCH_D_CAN)
+		priv->write_reg(priv, C_CAN_STS_REG, LEC_UNUSED);
 
-	/* status events have the highest priority */
-	if (irqstatus == STATUS_INTERRUPT) {
-		priv->current_status = priv->read_reg(priv,
-					C_CAN_STS_REG);
-
-		/* handle Tx/Rx events */
-		if (priv->current_status & STATUS_TXOK)
-			priv->write_reg(priv, C_CAN_STS_REG,
-					priv->current_status & ~STATUS_TXOK);
-
-		if (priv->current_status & STATUS_RXOK)
-			priv->write_reg(priv, C_CAN_STS_REG,
-					priv->current_status & ~STATUS_RXOK);
-
-		/* handle state changes */
-		if ((priv->current_status & STATUS_EWARN) &&
-				(!(priv->last_status & STATUS_EWARN))) {
-			netdev_dbg(dev, "entered error warning state\n");
-			work_done += c_can_handle_state_change(dev,
-						C_CAN_ERROR_WARNING);
-		}
-		if ((priv->current_status & STATUS_EPASS) &&
-				(!(priv->last_status & STATUS_EPASS))) {
-			netdev_dbg(dev, "entered error passive state\n");
-			work_done += c_can_handle_state_change(dev,
-						C_CAN_ERROR_PASSIVE);
-		}
-		if ((priv->current_status & STATUS_BOFF) &&
-				(!(priv->last_status & STATUS_BOFF))) {
-			netdev_dbg(dev, "entered bus off state\n");
-			work_done += c_can_handle_state_change(dev,
-						C_CAN_BUS_OFF);
-		}
+	/* handle state changes */
+	if ((curr & STATUS_EWARN) && (!(last & STATUS_EWARN))) {
+		netdev_dbg(dev, "entered error warning state\n");
+		work_done += c_can_handle_state_change(dev, C_CAN_ERROR_WARNING);
+	}
 
-		/* handle bus recovery events */
-		if ((!(priv->current_status & STATUS_BOFF)) &&
-				(priv->last_status & STATUS_BOFF)) {
-			netdev_dbg(dev, "left bus off state\n");
-			priv->can.state = CAN_STATE_ERROR_ACTIVE;
-		}
-		if ((!(priv->current_status & STATUS_EPASS)) &&
-				(priv->last_status & STATUS_EPASS)) {
-			netdev_dbg(dev, "left error passive state\n");
-			priv->can.state = CAN_STATE_ERROR_ACTIVE;
-		}
+	if ((curr & STATUS_EPASS) && (!(last & STATUS_EPASS))) {
+		netdev_dbg(dev, "entered error passive state\n");
+		work_done += c_can_handle_state_change(dev, C_CAN_ERROR_PASSIVE);
+	}
 
-		priv->last_status = priv->current_status;
-
-		/* handle lec errors on the bus */
-		lec_type = c_can_has_and_handle_berr(priv);
-		if (lec_type)
-			work_done += c_can_handle_bus_err(dev, lec_type);
-	} else if ((irqstatus >= C_CAN_MSG_OBJ_RX_FIRST) &&
-			(irqstatus <= C_CAN_MSG_OBJ_RX_LAST)) {
-		/* handle events corresponding to receive message objects */
-		work_done += c_can_do_rx_poll(dev, (quota - work_done));
-	} else if ((irqstatus >= C_CAN_MSG_OBJ_TX_FIRST) &&
-			(irqstatus <= C_CAN_MSG_OBJ_TX_LAST)) {
-		/* handle events corresponding to transmit message objects */
-		c_can_do_tx(dev);
+	if ((curr & STATUS_BOFF) && (!(last & STATUS_BOFF))) {
+		netdev_dbg(dev, "entered bus off state\n");
+		work_done += c_can_handle_state_change(dev, C_CAN_BUS_OFF);
+		goto end;
 	}
 
+	/* handle bus recovery events */
+	if ((!(curr & STATUS_BOFF)) && (last & STATUS_BOFF)) {
+		netdev_dbg(dev, "left bus off state\n");
+		priv->can.state = CAN_STATE_ERROR_ACTIVE;
+	}
+	if ((!(curr & STATUS_EPASS)) && (last & STATUS_EPASS)) {
+		netdev_dbg(dev, "left error passive state\n");
+		priv->can.state = CAN_STATE_ERROR_ACTIVE;
+	}
+
+	/* handle lec errors on the bus */
+	work_done += c_can_handle_bus_err(dev, curr & LEC_MASK);
+
+	/* Handle Tx/Rx events. We do this unconditionally */
+	work_done += c_can_do_rx_poll(dev, (quota - work_done));
+	c_can_do_tx(dev);
+
 end:
 	if (work_done < quota) {
 		napi_complete(napi);
-		/* enable all IRQs */
-		c_can_enable_all_interrupts(priv, ENABLE_ALL_INTERRUPTS);
+		/* enable all IRQs if we are not in bus off state */
+		if (priv->can.state != CAN_STATE_BUS_OFF)
+			c_can_irq_control(priv, true);
 	}
 
 	return work_done;
@@ -1142,12 +1053,11 @@ static irqreturn_t c_can_isr(int irq, void *dev_id)
 	struct net_device *dev = (struct net_device *)dev_id;
 	struct c_can_priv *priv = netdev_priv(dev);
 
-	priv->irqstatus = priv->read_reg(priv, C_CAN_INT_REG);
-	if (!priv->irqstatus)
+	if (!priv->read_reg(priv, C_CAN_INT_REG))
 		return IRQ_NONE;
 
 	/* disable all interrupts and schedule the NAPI */
-	c_can_enable_all_interrupts(priv, DISABLE_ALL_INTERRUPTS);
+	c_can_irq_control(priv, false);
 	napi_schedule(&priv->napi);
 
 	return IRQ_HANDLED;
@@ -1184,6 +1094,8 @@ static int c_can_open(struct net_device *dev)
 	can_led_event(dev, CAN_LED_EVENT_OPEN);
 
 	napi_enable(&priv->napi);
+	/* enable status change, error and module interrupts */
+	c_can_irq_control(priv, true);
 	netif_start_queue(dev);
 
 	return 0;
@@ -1226,7 +1138,6 @@ 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;
@@ -1281,6 +1192,7 @@ int c_can_power_up(struct net_device *dev)
 	u32 val;
 	unsigned long time_out;
 	struct c_can_priv *priv = netdev_priv(dev);
+	int ret;
 
 	if (!(dev->flags & IFF_UP))
 		return 0;
@@ -1307,7 +1219,11 @@ int c_can_power_up(struct net_device *dev)
 	if (time_after(jiffies, time_out))
 		return -ETIMEDOUT;
 
-	return c_can_start(dev);
+	ret = c_can_start(dev);
+	if (!ret)
+		c_can_irq_control(priv, true);
+
+	return ret;
 }
 EXPORT_SYMBOL_GPL(c_can_power_up);
 #endif