1 files changed, 148 insertions, 84 deletions

diff --git a/drivers/net/can/ti_hecc.c b/drivers/net/can/ti_hecc.c
index f8b19eef5d26..31ad364a89bb 100644
--- a/drivers/net/can/ti_hecc.c
+++ b/drivers/net/can/ti_hecc.c
@@ -73,6 +73,7 @@ MODULE_VERSION(HECC_MODULE_VERSION);
  */
 #define HECC_MAX_RX_MBOX	(HECC_MAX_MAILBOXES - HECC_MAX_TX_MBOX)
 #define HECC_RX_FIRST_MBOX	(HECC_MAX_MAILBOXES - 1)
+#define HECC_RX_LAST_MBOX	(HECC_MAX_TX_MBOX)
 
 /* TI HECC module registers */
 #define HECC_CANME		0x0	/* Mailbox enable */
@@ -82,7 +83,7 @@ MODULE_VERSION(HECC_MODULE_VERSION);
 #define HECC_CANTA		0x10	/* Transmission acknowledge */
 #define HECC_CANAA		0x14	/* Abort acknowledge */
 #define HECC_CANRMP		0x18	/* Receive message pending */
-#define HECC_CANRML		0x1C	/* Remote message lost */
+#define HECC_CANRML		0x1C	/* Receive message lost */
 #define HECC_CANRFP		0x20	/* Remote frame pending */
 #define HECC_CANGAM		0x24	/* SECC only:Global acceptance mask */
 #define HECC_CANMC		0x28	/* Master control */
@@ -149,6 +150,8 @@ MODULE_VERSION(HECC_MODULE_VERSION);
 #define HECC_BUS_ERROR		(HECC_CANES_FE | HECC_CANES_BE |\
 				HECC_CANES_CRCE | HECC_CANES_SE |\
 				HECC_CANES_ACKE)
+#define HECC_CANES_FLAGS	(HECC_BUS_ERROR | HECC_CANES_BO |\
+				HECC_CANES_EP | HECC_CANES_EW)
 
 #define HECC_CANMCF_RTR		BIT(4)	/* Remote transmit request */
 
@@ -382,8 +385,18 @@ static void ti_hecc_start(struct net_device *ndev)
 		hecc_set_bit(priv, HECC_CANMIM, mbx_mask);
 	}
 
-	/* Prevent message over-write & Enable interrupts */
-	hecc_write(priv, HECC_CANOPC, HECC_SET_REG);
+	/* Enable tx interrupts */
+	hecc_set_bit(priv, HECC_CANMIM, BIT(HECC_MAX_TX_MBOX) - 1);
+
+	/* Prevent message over-write to create a rx fifo, but not for
+	 * the lowest priority mailbox, since that allows detecting
+	 * overflows instead of the hardware silently dropping the
+	 * messages.
+	 */
+	mbx_mask = ~BIT(HECC_RX_LAST_MBOX);
+	hecc_write(priv, HECC_CANOPC, mbx_mask);
+
+	/* Enable interrupts */
 	if (priv->use_hecc1int) {
 		hecc_write(priv, HECC_CANMIL, HECC_SET_REG);
 		hecc_write(priv, HECC_CANGIM, HECC_CANGIM_DEF_MASK |
@@ -400,6 +413,9 @@ static void ti_hecc_stop(struct net_device *ndev)
 {
 	struct ti_hecc_priv *priv = netdev_priv(ndev);
 
+	/* Disable the CPK; stop sending, erroring and acking */
+	hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_CCR);
+
 	/* Disable interrupts and disable mailboxes */
 	hecc_write(priv, HECC_CANGIM, 0);
 	hecc_write(priv, HECC_CANMIM, 0);
@@ -508,8 +524,6 @@ static netdev_tx_t ti_hecc_xmit(struct sk_buff *skb, struct net_device *ndev)
 	hecc_set_bit(priv, HECC_CANME, mbx_mask);
 	spin_unlock_irqrestore(&priv->mbx_lock, flags);
 
-	hecc_clear_bit(priv, HECC_CANMD, mbx_mask);
-	hecc_set_bit(priv, HECC_CANMIM, mbx_mask);
 	hecc_write(priv, HECC_CANTRS, mbx_mask);
 
 	return NETDEV_TX_OK;
@@ -526,8 +540,10 @@ static unsigned int ti_hecc_mailbox_read(struct can_rx_offload *offload,
 					 u32 *timestamp, unsigned int mbxno)
 {
 	struct ti_hecc_priv *priv = rx_offload_to_priv(offload);
-	u32 data;
+	u32 data, mbx_mask;
+	int ret = 1;
 
+	mbx_mask = BIT(mbxno);
 	data = hecc_read_mbx(priv, mbxno, HECC_CANMID);
 	if (data & HECC_CANMID_IDE)
 		cf->can_id = (data & CAN_EFF_MASK) | CAN_EFF_FLAG;
@@ -548,7 +564,25 @@ static unsigned int ti_hecc_mailbox_read(struct can_rx_offload *offload,
 
 	*timestamp = hecc_read_stamp(priv, mbxno);
 
-	return 1;
+	/* Check for FIFO overrun.
+	 *
+	 * All but the last RX mailbox have activated overwrite
+	 * protection. So skip check for overrun, if we're not
+	 * handling the last RX mailbox.
+	 *
+	 * As the overwrite protection for the last RX mailbox is
+	 * disabled, the CAN core might update while we're reading
+	 * it. This means the skb might be inconsistent.
+	 *
+	 * Return an error to let rx-offload discard this CAN frame.
+	 */
+	if (unlikely(mbxno == HECC_RX_LAST_MBOX &&
+		     hecc_read(priv, HECC_CANRML) & mbx_mask))
+		ret = -ENOBUFS;
+
+	hecc_write(priv, HECC_CANRMP, mbx_mask);
+
+	return ret;
 }
 
 static int ti_hecc_error(struct net_device *ndev, int int_status,
@@ -558,92 +592,73 @@ static int ti_hecc_error(struct net_device *ndev, int int_status,
 	struct can_frame *cf;
 	struct sk_buff *skb;
 	u32 timestamp;
+	int err;
 
-	/* propagate the error condition to the can stack */
-	skb = alloc_can_err_skb(ndev, &cf);
-	if (!skb) {
-		if (printk_ratelimit())
-			netdev_err(priv->ndev,
-				   "%s: alloc_can_err_skb() failed\n",
-				   __func__);
-		return -ENOMEM;
-	}
-
-	if (int_status & HECC_CANGIF_WLIF) { /* warning level int */
-		if ((int_status & HECC_CANGIF_BOIF) == 0) {
-			priv->can.state = CAN_STATE_ERROR_WARNING;
-			++priv->can.can_stats.error_warning;
-			cf->can_id |= CAN_ERR_CRTL;
-			if (hecc_read(priv, HECC_CANTEC) > 96)
-				cf->data[1] |= CAN_ERR_CRTL_TX_WARNING;
-			if (hecc_read(priv, HECC_CANREC) > 96)
-				cf->data[1] |= CAN_ERR_CRTL_RX_WARNING;
-		}
-		hecc_set_bit(priv, HECC_CANES, HECC_CANES_EW);
-		netdev_dbg(priv->ndev, "Error Warning interrupt\n");
-		hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_CCR);
-	}
-
-	if (int_status & HECC_CANGIF_EPIF) { /* error passive int */
-		if ((int_status & HECC_CANGIF_BOIF) == 0) {
-			priv->can.state = CAN_STATE_ERROR_PASSIVE;
-			++priv->can.can_stats.error_passive;
-			cf->can_id |= CAN_ERR_CRTL;
-			if (hecc_read(priv, HECC_CANTEC) > 127)
-				cf->data[1] |= CAN_ERR_CRTL_TX_PASSIVE;
-			if (hecc_read(priv, HECC_CANREC) > 127)
-				cf->data[1] |= CAN_ERR_CRTL_RX_PASSIVE;
+	if (err_status & HECC_BUS_ERROR) {
+		/* propagate the error condition to the can stack */
+		skb = alloc_can_err_skb(ndev, &cf);
+		if (!skb) {
+			if (net_ratelimit())
+				netdev_err(priv->ndev,
+					   "%s: alloc_can_err_skb() failed\n",
+					   __func__);
+			return -ENOMEM;
 		}
-		hecc_set_bit(priv, HECC_CANES, HECC_CANES_EP);
-		netdev_dbg(priv->ndev, "Error passive interrupt\n");
-		hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_CCR);
-	}
-
-	/* Need to check busoff condition in error status register too to
-	 * ensure warning interrupts don't hog the system
-	 */
-	if ((int_status & HECC_CANGIF_BOIF) || (err_status & HECC_CANES_BO)) {
-		priv->can.state = CAN_STATE_BUS_OFF;
-		cf->can_id |= CAN_ERR_BUSOFF;
-		hecc_set_bit(priv, HECC_CANES, HECC_CANES_BO);
-		hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_CCR);
-		/* Disable all interrupts in bus-off to avoid int hog */
-		hecc_write(priv, HECC_CANGIM, 0);
-		++priv->can.can_stats.bus_off;
-		can_bus_off(ndev);
-	}
 
-	if (err_status & HECC_BUS_ERROR) {
 		++priv->can.can_stats.bus_error;
 		cf->can_id |= CAN_ERR_BUSERROR | CAN_ERR_PROT;
-		if (err_status & HECC_CANES_FE) {
-			hecc_set_bit(priv, HECC_CANES, HECC_CANES_FE);
+		if (err_status & HECC_CANES_FE)
 			cf->data[2] |= CAN_ERR_PROT_FORM;
-		}
-		if (err_status & HECC_CANES_BE) {
-			hecc_set_bit(priv, HECC_CANES, HECC_CANES_BE);
+		if (err_status & HECC_CANES_BE)
 			cf->data[2] |= CAN_ERR_PROT_BIT;
-		}
-		if (err_status & HECC_CANES_SE) {
-			hecc_set_bit(priv, HECC_CANES, HECC_CANES_SE);
+		if (err_status & HECC_CANES_SE)
 			cf->data[2] |= CAN_ERR_PROT_STUFF;
-		}
-		if (err_status & HECC_CANES_CRCE) {
-			hecc_set_bit(priv, HECC_CANES, HECC_CANES_CRCE);
+		if (err_status & HECC_CANES_CRCE)
 			cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
-		}
-		if (err_status & HECC_CANES_ACKE) {
-			hecc_set_bit(priv, HECC_CANES, HECC_CANES_ACKE);
+		if (err_status & HECC_CANES_ACKE)
 			cf->data[3] = CAN_ERR_PROT_LOC_ACK;
-		}
+
+		timestamp = hecc_read(priv, HECC_CANLNT);
+		err = can_rx_offload_queue_sorted(&priv->offload, skb,
+						  timestamp);
+		if (err)
+			ndev->stats.rx_fifo_errors++;
 	}
 
-	timestamp = hecc_read(priv, HECC_CANLNT);
-	can_rx_offload_queue_sorted(&priv->offload, skb, timestamp);
+	hecc_write(priv, HECC_CANES, HECC_CANES_FLAGS);
 
 	return 0;
 }
 
+static void ti_hecc_change_state(struct net_device *ndev,
+				 enum can_state rx_state,
+				 enum can_state tx_state)
+{
+	struct ti_hecc_priv *priv = netdev_priv(ndev);
+	struct can_frame *cf;
+	struct sk_buff *skb;
+	u32 timestamp;
+	int err;
+
+	skb = alloc_can_err_skb(priv->ndev, &cf);
+	if (unlikely(!skb)) {
+		priv->can.state = max(tx_state, rx_state);
+		return;
+	}
+
+	can_change_state(priv->ndev, cf, tx_state, rx_state);
+
+	if (max(tx_state, rx_state) != CAN_STATE_BUS_OFF) {
+		cf->data[6] = hecc_read(priv, HECC_CANTEC);
+		cf->data[7] = hecc_read(priv, HECC_CANREC);
+	}
+
+	timestamp = hecc_read(priv, HECC_CANLNT);
+	err = can_rx_offload_queue_sorted(&priv->offload, skb, timestamp);
+	if (err)
+		ndev->stats.rx_fifo_errors++;
+}
+
 static irqreturn_t ti_hecc_interrupt(int irq, void *dev_id)
 {
 	struct net_device *ndev = (struct net_device *)dev_id;
@@ -651,6 +666,7 @@ static irqreturn_t ti_hecc_interrupt(int irq, void *dev_id)
 	struct net_device_stats *stats = &ndev->stats;
 	u32 mbxno, mbx_mask, int_status, err_status, stamp;
 	unsigned long flags, rx_pending;
+	u32 handled = 0;
 
 	int_status = hecc_read(priv,
 			       priv->use_hecc1int ?
@@ -660,17 +676,66 @@ static irqreturn_t ti_hecc_interrupt(int irq, void *dev_id)
 		return IRQ_NONE;
 
 	err_status = hecc_read(priv, HECC_CANES);
-	if (err_status & (HECC_BUS_ERROR | HECC_CANES_BO |
-			  HECC_CANES_EP | HECC_CANES_EW))
+	if (unlikely(err_status & HECC_CANES_FLAGS))
 		ti_hecc_error(ndev, int_status, err_status);
 
+	if (unlikely(int_status & HECC_CANGIM_DEF_MASK)) {
+		enum can_state rx_state, tx_state;
+		u32 rec = hecc_read(priv, HECC_CANREC);
+		u32 tec = hecc_read(priv, HECC_CANTEC);
+
+		if (int_status & HECC_CANGIF_WLIF) {
+			handled |= HECC_CANGIF_WLIF;
+			rx_state = rec >= tec ? CAN_STATE_ERROR_WARNING : 0;
+			tx_state = rec <= tec ? CAN_STATE_ERROR_WARNING : 0;
+			netdev_dbg(priv->ndev, "Error Warning interrupt\n");
+			ti_hecc_change_state(ndev, rx_state, tx_state);
+		}
+
+		if (int_status & HECC_CANGIF_EPIF) {
+			handled |= HECC_CANGIF_EPIF;
+			rx_state = rec >= tec ? CAN_STATE_ERROR_PASSIVE : 0;
+			tx_state = rec <= tec ? CAN_STATE_ERROR_PASSIVE : 0;
+			netdev_dbg(priv->ndev, "Error passive interrupt\n");
+			ti_hecc_change_state(ndev, rx_state, tx_state);
+		}
+
+		if (int_status & HECC_CANGIF_BOIF) {
+			handled |= HECC_CANGIF_BOIF;
+			rx_state = CAN_STATE_BUS_OFF;
+			tx_state = CAN_STATE_BUS_OFF;
+			netdev_dbg(priv->ndev, "Bus off interrupt\n");
+
+			/* Disable all interrupts */
+			hecc_write(priv, HECC_CANGIM, 0);
+			can_bus_off(ndev);
+			ti_hecc_change_state(ndev, rx_state, tx_state);
+		}
+	} else if (unlikely(priv->can.state != CAN_STATE_ERROR_ACTIVE)) {
+		enum can_state new_state, tx_state, rx_state;
+		u32 rec = hecc_read(priv, HECC_CANREC);
+		u32 tec = hecc_read(priv, HECC_CANTEC);
+
+		if (rec >= 128 || tec >= 128)
+			new_state = CAN_STATE_ERROR_PASSIVE;
+		else if (rec >= 96 || tec >= 96)
+			new_state = CAN_STATE_ERROR_WARNING;
+		else
+			new_state = CAN_STATE_ERROR_ACTIVE;
+
+		if (new_state < priv->can.state) {
+			rx_state = rec >= tec ? new_state : 0;
+			tx_state = rec <= tec ? new_state : 0;
+			ti_hecc_change_state(ndev, rx_state, tx_state);
+		}
+	}
+
 	if (int_status & HECC_CANGIF_GMIF) {
 		while (priv->tx_tail - priv->tx_head > 0) {
 			mbxno = get_tx_tail_mb(priv);
 			mbx_mask = BIT(mbxno);
 			if (!(mbx_mask & hecc_read(priv, HECC_CANTA)))
 				break;
-			hecc_clear_bit(priv, HECC_CANMIM, mbx_mask);
 			hecc_write(priv, HECC_CANTA, mbx_mask);
 			spin_lock_irqsave(&priv->mbx_lock, flags);
 			hecc_clear_bit(priv, HECC_CANME, mbx_mask);
@@ -695,16 +760,15 @@ static irqreturn_t ti_hecc_interrupt(int irq, void *dev_id)
 		while ((rx_pending = hecc_read(priv, HECC_CANRMP))) {
 			can_rx_offload_irq_offload_timestamp(&priv->offload,
 							     rx_pending);
-			hecc_write(priv, HECC_CANRMP, rx_pending);
 		}
 	}
 
 	/* clear all interrupt conditions - read back to avoid spurious ints */
 	if (priv->use_hecc1int) {
-		hecc_write(priv, HECC_CANGIF1, HECC_SET_REG);
+		hecc_write(priv, HECC_CANGIF1, handled);
 		int_status = hecc_read(priv, HECC_CANGIF1);
 	} else {
-		hecc_write(priv, HECC_CANGIF0, HECC_SET_REG);
+		hecc_write(priv, HECC_CANGIF0, handled);
 		int_status = hecc_read(priv, HECC_CANGIF0);
 	}
 
@@ -877,7 +941,7 @@ static int ti_hecc_probe(struct platform_device *pdev)
 
 	priv->offload.mailbox_read = ti_hecc_mailbox_read;
 	priv->offload.mb_first = HECC_RX_FIRST_MBOX;
-	priv->offload.mb_last = HECC_MAX_TX_MBOX;
+	priv->offload.mb_last = HECC_RX_LAST_MBOX;
 	err = can_rx_offload_add_timestamp(ndev, &priv->offload);
 	if (err) {
 		dev_err(&pdev->dev, "can_rx_offload_add_timestamp() failed\n");