diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index 80c46ad4cee4..ad0a7e8c2c2b 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -592,13 +592,12 @@ static int flexcan_poll_state(struct net_device *dev, u32 reg_esr)
 		rx_state = unlikely(reg_esr & FLEXCAN_ESR_RX_WRN) ?
 			   CAN_STATE_ERROR_WARNING : CAN_STATE_ERROR_ACTIVE;
 		new_state = max(tx_state, rx_state);
-	} else if (unlikely(flt == FLEXCAN_ESR_FLT_CONF_PASSIVE)) {
+	} else {
 		__flexcan_get_berr_counter(dev, &bec);
-		new_state = CAN_STATE_ERROR_PASSIVE;
+		new_state = flt == FLEXCAN_ESR_FLT_CONF_PASSIVE ?
+			    CAN_STATE_ERROR_PASSIVE : CAN_STATE_BUS_OFF;
 		rx_state = bec.rxerr >= bec.txerr ? new_state : 0;
 		tx_state = bec.rxerr <= bec.txerr ? new_state : 0;
-	} else {
-		new_state = CAN_STATE_BUS_OFF;
 	}
 
 	/* state hasn't changed */
@@ -1158,12 +1157,19 @@ static int flexcan_probe(struct platform_device *pdev)
 	const struct flexcan_devtype_data *devtype_data;
 	struct net_device *dev;
 	struct flexcan_priv *priv;
+	struct regulator *reg_xceiver;
 	struct resource *mem;
 	struct clk *clk_ipg = NULL, *clk_per = NULL;
 	void __iomem *base;
 	int err, irq;
 	u32 clock_freq = 0;
 
+	reg_xceiver = devm_regulator_get(&pdev->dev, "xceiver");
+	if (PTR_ERR(reg_xceiver) == -EPROBE_DEFER)
+		return -EPROBE_DEFER;
+	else if (IS_ERR(reg_xceiver))
+		reg_xceiver = NULL;
+
 	if (pdev->dev.of_node)
 		of_property_read_u32(pdev->dev.of_node,
 						"clock-frequency", &clock_freq);
@@ -1224,9 +1230,7 @@ static int flexcan_probe(struct platform_device *pdev)
 	priv->pdata = dev_get_platdata(&pdev->dev);
 	priv->devtype_data = devtype_data;
 
-	priv->reg_xceiver = devm_regulator_get(&pdev->dev, "xceiver");
-	if (IS_ERR(priv->reg_xceiver))
-		priv->reg_xceiver = NULL;
+	priv->reg_xceiver = reg_xceiver;
 
 	netif_napi_add(dev, &priv->napi, flexcan_poll, FLEXCAN_NAPI_WEIGHT);
 
diff --git a/drivers/net/can/usb/gs_usb.c b/drivers/net/can/usb/gs_usb.c
index 009acc8641fc..8b4d3e6875eb 100644
--- a/drivers/net/can/usb/gs_usb.c
+++ b/drivers/net/can/usb/gs_usb.c
@@ -901,6 +901,8 @@ static int gs_usb_probe(struct usb_interface *intf, const struct usb_device_id *
 	}
 
 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	if (!dev)
+		return -ENOMEM;
 	init_usb_anchor(&dev->rx_submitted);
 
 	atomic_set(&dev->active_channels, 0);
diff --git a/drivers/net/can/usb/kvaser_usb.c b/drivers/net/can/usb/kvaser_usb.c
index e97a08ce0b90..57611fd91229 100644
--- a/drivers/net/can/usb/kvaser_usb.c
+++ b/drivers/net/can/usb/kvaser_usb.c
@@ -25,7 +25,6 @@
 #include <linux/can/dev.h>
 #include <linux/can/error.h>
 
-#define MAX_TX_URBS			16
 #define MAX_RX_URBS			4
 #define START_TIMEOUT			1000 /* msecs */
 #define STOP_TIMEOUT			1000 /* msecs */
@@ -443,6 +442,7 @@ struct kvaser_usb_error_summary {
 	};
 };
 
+/* Context for an outstanding, not yet ACKed, transmission */
 struct kvaser_usb_tx_urb_context {
 	struct kvaser_usb_net_priv *priv;
 	u32 echo_index;
@@ -456,8 +456,13 @@ struct kvaser_usb {
 	struct usb_endpoint_descriptor *bulk_in, *bulk_out;
 	struct usb_anchor rx_submitted;
 
+	/* @max_tx_urbs: Firmware-reported maximum number of oustanding,
+	 * not yet ACKed, transmissions on this device. This value is
+	 * also used as a sentinel for marking free tx contexts.
+	 */
 	u32 fw_version;
 	unsigned int nchannels;
+	unsigned int max_tx_urbs;
 	enum kvaser_usb_family family;
 
 	bool rxinitdone;
@@ -467,19 +472,18 @@ struct kvaser_usb {
 
 struct kvaser_usb_net_priv {
 	struct can_priv can;
-
-	spinlock_t tx_contexts_lock;
-	int active_tx_contexts;
-	struct kvaser_usb_tx_urb_context tx_contexts[MAX_TX_URBS];
-
-	struct usb_anchor tx_submitted;
-	struct completion start_comp, stop_comp;
+	struct can_berr_counter bec;
 
 	struct kvaser_usb *dev;
 	struct net_device *netdev;
 	int channel;
 
-	struct can_berr_counter bec;
+	struct completion start_comp, stop_comp;
+	struct usb_anchor tx_submitted;
+
+	spinlock_t tx_contexts_lock;
+	int active_tx_contexts;
+	struct kvaser_usb_tx_urb_context tx_contexts[];
 };
 
 static const struct usb_device_id kvaser_usb_table[] = {
@@ -592,8 +596,8 @@ static int kvaser_usb_wait_msg(const struct kvaser_usb *dev, u8 id,
 			 * for further details.
 			 */
 			if (tmp->len == 0) {
-				pos = round_up(pos,
-					       dev->bulk_in->wMaxPacketSize);
+				pos = round_up(pos, le16_to_cpu(dev->bulk_in->
+								wMaxPacketSize));
 				continue;
 			}
 
@@ -657,9 +661,13 @@ static int kvaser_usb_get_software_info(struct kvaser_usb *dev)
 	switch (dev->family) {
 	case KVASER_LEAF:
 		dev->fw_version = le32_to_cpu(msg.u.leaf.softinfo.fw_version);
+		dev->max_tx_urbs =
+			le16_to_cpu(msg.u.leaf.softinfo.max_outstanding_tx);
 		break;
 	case KVASER_USBCAN:
 		dev->fw_version = le32_to_cpu(msg.u.usbcan.softinfo.fw_version);
+		dev->max_tx_urbs =
+			le16_to_cpu(msg.u.usbcan.softinfo.max_outstanding_tx);
 		break;
 	}
 
@@ -715,7 +723,7 @@ static void kvaser_usb_tx_acknowledge(const struct kvaser_usb *dev,
 
 	stats = &priv->netdev->stats;
 
-	context = &priv->tx_contexts[tid % MAX_TX_URBS];
+	context = &priv->tx_contexts[tid % dev->max_tx_urbs];
 
 	/* Sometimes the state change doesn't come after a bus-off event */
 	if (priv->can.restart_ms &&
@@ -744,7 +752,7 @@ static void kvaser_usb_tx_acknowledge(const struct kvaser_usb *dev,
 	spin_lock_irqsave(&priv->tx_contexts_lock, flags);
 
 	can_get_echo_skb(priv->netdev, context->echo_index);
-	context->echo_index = MAX_TX_URBS;
+	context->echo_index = dev->max_tx_urbs;
 	--priv->active_tx_contexts;
 	netif_wake_queue(priv->netdev);
 
@@ -1329,7 +1337,8 @@ static void kvaser_usb_read_bulk_callback(struct urb *urb)
 		 * number of events in case of a heavy rx load on the bus.
 		 */
 		if (msg->len == 0) {
-			pos = round_up(pos, dev->bulk_in->wMaxPacketSize);
+			pos = round_up(pos, le16_to_cpu(dev->bulk_in->
+							wMaxPacketSize));
 			continue;
 		}
 
@@ -1512,11 +1521,13 @@ static int kvaser_usb_open(struct net_device *netdev)
 
 static void kvaser_usb_reset_tx_urb_contexts(struct kvaser_usb_net_priv *priv)
 {
-	int i;
+	int i, max_tx_urbs;
+
+	max_tx_urbs = priv->dev->max_tx_urbs;
 
 	priv->active_tx_contexts = 0;
-	for (i = 0; i < MAX_TX_URBS; i++)
-		priv->tx_contexts[i].echo_index = MAX_TX_URBS;
+	for (i = 0; i < max_tx_urbs; i++)
+		priv->tx_contexts[i].echo_index = max_tx_urbs;
 }
 
 /* This method might sleep. Do not call it in the atomic context
@@ -1702,14 +1713,14 @@ static netdev_tx_t kvaser_usb_start_xmit(struct sk_buff *skb,
 		*msg_tx_can_flags |= MSG_FLAG_REMOTE_FRAME;
 
 	spin_lock_irqsave(&priv->tx_contexts_lock, flags);
-	for (i = 0; i < ARRAY_SIZE(priv->tx_contexts); i++) {
-		if (priv->tx_contexts[i].echo_index == MAX_TX_URBS) {
+	for (i = 0; i < dev->max_tx_urbs; i++) {
+		if (priv->tx_contexts[i].echo_index == dev->max_tx_urbs) {
 			context = &priv->tx_contexts[i];
 
 			context->echo_index = i;
 			can_put_echo_skb(skb, netdev, context->echo_index);
 			++priv->active_tx_contexts;
-			if (priv->active_tx_contexts >= MAX_TX_URBS)
+			if (priv->active_tx_contexts >= dev->max_tx_urbs)
 				netif_stop_queue(netdev);
 
 			break;
@@ -1743,7 +1754,7 @@ static netdev_tx_t kvaser_usb_start_xmit(struct sk_buff *skb,
 		spin_lock_irqsave(&priv->tx_contexts_lock, flags);
 
 		can_free_echo_skb(netdev, context->echo_index);
-		context->echo_index = MAX_TX_URBS;
+		context->echo_index = dev->max_tx_urbs;
 		--priv->active_tx_contexts;
 		netif_wake_queue(netdev);
 
@@ -1881,7 +1892,9 @@ static int kvaser_usb_init_one(struct usb_interface *intf,
 	if (err)
 		return err;
 
-	netdev = alloc_candev(sizeof(*priv), MAX_TX_URBS);
+	netdev = alloc_candev(sizeof(*priv) +
+			      dev->max_tx_urbs * sizeof(*priv->tx_contexts),
+			      dev->max_tx_urbs);
 	if (!netdev) {
 		dev_err(&intf->dev, "Cannot alloc candev\n");
 		return -ENOMEM;
@@ -2009,6 +2022,13 @@ static int kvaser_usb_probe(struct usb_interface *intf,
 		return err;
 	}
 
+	dev_dbg(&intf->dev, "Firmware version: %d.%d.%d\n",
+		((dev->fw_version >> 24) & 0xff),
+		((dev->fw_version >> 16) & 0xff),
+		(dev->fw_version & 0xffff));
+
+	dev_dbg(&intf->dev, "Max oustanding tx = %d URBs\n", dev->max_tx_urbs);
+
 	err = kvaser_usb_get_card_info(dev);
 	if (err) {
 		dev_err(&intf->dev,
@@ -2016,11 +2036,6 @@ static int kvaser_usb_probe(struct usb_interface *intf,
 		return err;
 	}
 
-	dev_dbg(&intf->dev, "Firmware version: %d.%d.%d\n",
-		((dev->fw_version >> 24) & 0xff),
-		((dev->fw_version >> 16) & 0xff),
-		(dev->fw_version & 0xffff));
-
 	for (i = 0; i < dev->nchannels; i++) {
 		err = kvaser_usb_init_one(intf, id, i);
 		if (err) {
diff --git a/drivers/net/can/usb/peak_usb/pcan_ucan.h b/drivers/net/can/usb/peak_usb/pcan_ucan.h
index 1ba7c25002e1..e8fc4952c6b0 100644
--- a/drivers/net/can/usb/peak_usb/pcan_ucan.h
+++ b/drivers/net/can/usb/peak_usb/pcan_ucan.h
@@ -26,8 +26,8 @@
 #define PUCAN_CMD_FILTER_STD		0x008
 #define PUCAN_CMD_TX_ABORT		0x009
 #define PUCAN_CMD_WR_ERR_CNT		0x00a
-#define PUCAN_CMD_RX_FRAME_ENABLE	0x00b
-#define PUCAN_CMD_RX_FRAME_DISABLE	0x00c
+#define PUCAN_CMD_SET_EN_OPTION		0x00b
+#define PUCAN_CMD_CLR_DIS_OPTION	0x00c
 #define PUCAN_CMD_END_OF_COLLECTION	0x3ff
 
 /* uCAN received messages list */
@@ -101,14 +101,15 @@ struct __packed pucan_wr_err_cnt {
 	u16	unused;
 };
 
-/* uCAN RX_FRAME_ENABLE command fields */
-#define PUCAN_FLTEXT_ERROR		0x0001
-#define PUCAN_FLTEXT_BUSLOAD		0x0002
+/* uCAN SET_EN/CLR_DIS _OPTION command fields */
+#define PUCAN_OPTION_ERROR		0x0001
+#define PUCAN_OPTION_BUSLOAD		0x0002
+#define PUCAN_OPTION_CANDFDISO		0x0004
 
-struct __packed pucan_filter_ext {
+struct __packed pucan_options {
 	__le16	opcode_channel;
 
-	__le16	ext_mask;
+	__le16	options;
 	u32	unused;
 };
 
diff --git a/drivers/net/can/usb/peak_usb/pcan_usb_fd.c b/drivers/net/can/usb/peak_usb/pcan_usb_fd.c
index 0bac0f14edc3..a9221ad9f1a0 100644
--- a/drivers/net/can/usb/peak_usb/pcan_usb_fd.c
+++ b/drivers/net/can/usb/peak_usb/pcan_usb_fd.c
@@ -110,13 +110,13 @@ struct __packed pcan_ufd_led {
 	u8	unused[5];
 };
 
-/* Extended usage of uCAN commands CMD_RX_FRAME_xxxABLE for PCAN-USB Pro FD */
+/* Extended usage of uCAN commands CMD_xxx_xx_OPTION for PCAN-USB Pro FD */
 #define PCAN_UFD_FLTEXT_CALIBRATION	0x8000
 
-struct __packed pcan_ufd_filter_ext {
+struct __packed pcan_ufd_options {
 	__le16	opcode_channel;
 
-	__le16	ext_mask;
+	__le16	ucan_mask;
 	u16	unused;
 	__le16	usb_mask;
 };
@@ -251,6 +251,27 @@ static int pcan_usb_fd_build_restart_cmd(struct peak_usb_device *dev, u8 *buf)
 	/* moves the pointer forward */
 	pc += sizeof(struct pucan_wr_err_cnt);
 
+	/* add command to switch from ISO to non-ISO mode, if fw allows it */
+	if (dev->can.ctrlmode_supported & CAN_CTRLMODE_FD_NON_ISO) {
+		struct pucan_options *puo = (struct pucan_options *)pc;
+
+		puo->opcode_channel =
+			(dev->can.ctrlmode & CAN_CTRLMODE_FD_NON_ISO) ?
+			pucan_cmd_opcode_channel(dev,
+						 PUCAN_CMD_CLR_DIS_OPTION) :
+			pucan_cmd_opcode_channel(dev, PUCAN_CMD_SET_EN_OPTION);
+
+		puo->options = cpu_to_le16(PUCAN_OPTION_CANDFDISO);
+
+		/* to be sure that no other extended bits will be taken into
+		 * account
+		 */
+		puo->unused = 0;
+
+		/* moves the pointer forward */
+		pc += sizeof(struct pucan_options);
+	}
+
 	/* next, go back to operational mode */
 	cmd = (struct pucan_command *)pc;
 	cmd->opcode_channel = pucan_cmd_opcode_channel(dev,
@@ -321,21 +342,21 @@ static int pcan_usb_fd_set_filter_std(struct peak_usb_device *dev, int idx,
 	return pcan_usb_fd_send_cmd(dev, cmd);
 }
 
-/* set/unset notifications filter:
+/* set/unset options
  *
- *	onoff	sets(1)/unset(0) notifications
- *	mask	each bit defines a kind of notification to set/unset
+ *	onoff	set(1)/unset(0) options
+ *	mask	each bit defines a kind of options to set/unset
  */
-static int pcan_usb_fd_set_filter_ext(struct peak_usb_device *dev,
-				      bool onoff, u16 ext_mask, u16 usb_mask)
+static int pcan_usb_fd_set_options(struct peak_usb_device *dev,
+				   bool onoff, u16 ucan_mask, u16 usb_mask)
 {
-	struct pcan_ufd_filter_ext *cmd = pcan_usb_fd_cmd_buffer(dev);
+	struct pcan_ufd_options *cmd = pcan_usb_fd_cmd_buffer(dev);
 
 	cmd->opcode_channel = pucan_cmd_opcode_channel(dev,
-					(onoff) ? PUCAN_CMD_RX_FRAME_ENABLE :
-						  PUCAN_CMD_RX_FRAME_DISABLE);
+					(onoff) ? PUCAN_CMD_SET_EN_OPTION :
+						  PUCAN_CMD_CLR_DIS_OPTION);
 
-	cmd->ext_mask = cpu_to_le16(ext_mask);
+	cmd->ucan_mask = cpu_to_le16(ucan_mask);
 	cmd->usb_mask = cpu_to_le16(usb_mask);
 
 	/* send the command */
@@ -770,9 +791,9 @@ static int pcan_usb_fd_start(struct peak_usb_device *dev)
 				       &pcan_usb_pro_fd);
 
 		/* enable USB calibration messages */
-		err = pcan_usb_fd_set_filter_ext(dev, 1,
-						 PUCAN_FLTEXT_ERROR,
-						 PCAN_UFD_FLTEXT_CALIBRATION);
+		err = pcan_usb_fd_set_options(dev, 1,
+					      PUCAN_OPTION_ERROR,
+					      PCAN_UFD_FLTEXT_CALIBRATION);
 	}
 
 	pdev->usb_if->dev_opened_count++;
@@ -806,9 +827,9 @@ static int pcan_usb_fd_stop(struct peak_usb_device *dev)
 
 	/* turn off special msgs for that interface if no other dev opened */
 	if (pdev->usb_if->dev_opened_count == 1)
-		pcan_usb_fd_set_filter_ext(dev, 0,
-					   PUCAN_FLTEXT_ERROR,
-					   PCAN_UFD_FLTEXT_CALIBRATION);
+		pcan_usb_fd_set_options(dev, 0,
+					PUCAN_OPTION_ERROR,
+					PCAN_UFD_FLTEXT_CALIBRATION);
 	pdev->usb_if->dev_opened_count--;
 
 	return 0;
@@ -860,8 +881,14 @@ static int pcan_usb_fd_init(struct peak_usb_device *dev)
 			 pdev->usb_if->fw_info.fw_version[2],
 			 dev->adapter->ctrl_count);
 
-		/* the currently supported hw is non-ISO */
-		dev->can.ctrlmode = CAN_CTRLMODE_FD_NON_ISO;
+		/* check for ability to switch between ISO/non-ISO modes */
+		if (pdev->usb_if->fw_info.fw_version[0] >= 2) {
+			/* firmware >= 2.x supports ISO/non-ISO switching */
+			dev->can.ctrlmode_supported |= CAN_CTRLMODE_FD_NON_ISO;
+		} else {
+			/* firmware < 2.x only supports fixed(!) non-ISO */
+			dev->can.ctrlmode |= CAN_CTRLMODE_FD_NON_ISO;
+		}
 
 		/* tell the hardware the can driver is running */
 		err = pcan_usb_fd_drv_loaded(dev, 1);
@@ -937,9 +964,9 @@ static void pcan_usb_fd_exit(struct peak_usb_device *dev)
 	if (dev->ctrl_idx == 0) {
 		/* turn off calibration message if any device were opened */
 		if (pdev->usb_if->dev_opened_count > 0)
-			pcan_usb_fd_set_filter_ext(dev, 0,
-						   PUCAN_FLTEXT_ERROR,
-						   PCAN_UFD_FLTEXT_CALIBRATION);
+			pcan_usb_fd_set_options(dev, 0,
+						PUCAN_OPTION_ERROR,
+						PCAN_UFD_FLTEXT_CALIBRATION);
 
 		/* tell USB adapter that the driver is being unloaded */
 		pcan_usb_fd_drv_loaded(dev, 0);