Merge tag 'linux-can-fixes-for-3.18-20141118' of git://gitorious.org/linux-can/linux-can

Marc Kleine-Budde says:

====================
pull-request: can 2014-11-18

this is a pull request of 17 patches for net/master for the v3.18 release
cycle.

The last patch of this pull request ("can: m_can: update to support CAN FD
features") adds, as the description says, a new feature to the m_can driver. As
the m_can driver has been added in v3.18 there is no risk of causing a
regression. Give me a note if this is not okay and I'll create a new pull
request without it.

There is a patch for the CAN infrastructure by Thomas Körper which fixes
calling kfree_skb() from interrupt context. Roman Fietze fixes a typo also in
the infrastructure. A patch by Dong Aisheng adds a generic helper function to
tell if a skb is normal CAN or CAN-FD frame. Alexey Khoroshilov of the Linux
Driver Verification project fixes a memory leak in the esd_usb2 driver. Two
patches by Sudip Mukherjee remove unused variables and fixe the signess of a
variable. Three patches by me add the missing .ndo_change_mtu callback to the
xilinx_can, rcar_can and gs_usb driver.

The remaining patches improve the m_can driver: David Cohen adds the missing
CONFIG_HAS_IOMEM dependency. Dong Aisheng provides 6 bugfix patches (most
important: missing RAM init, sleep in NAPI poll, dlc in RTR). While the last of
his patches adds CAN FD support to the driver.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

10 files changed, 183 insertions, 64 deletions

diff --git a/drivers/net/can/dev.c b/drivers/net/can/dev.c
index 02492d241e4c..2cfe5012e4e5 100644
--- a/drivers/net/can/dev.c
+++ b/drivers/net/can/dev.c
@@ -110,7 +110,7 @@ static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
 	long rate;
 	u64 v64;
 
-	/* Use CIA recommended sample points */
+	/* Use CiA recommended sample points */
 	if (bt->sample_point) {
 		sampl_pt = bt->sample_point;
 	} else {
@@ -382,7 +382,7 @@ void can_free_echo_skb(struct net_device *dev, unsigned int idx)
 	BUG_ON(idx >= priv->echo_skb_max);
 
 	if (priv->echo_skb[idx]) {
-		kfree_skb(priv->echo_skb[idx]);
+		dev_kfree_skb_any(priv->echo_skb[idx]);
 		priv->echo_skb[idx] = NULL;
 	}
 }
diff --git a/drivers/net/can/m_can/Kconfig b/drivers/net/can/m_can/Kconfig
index fca5482c09ac..04f20dd39007 100644
--- a/drivers/net/can/m_can/Kconfig
+++ b/drivers/net/can/m_can/Kconfig
@@ -1,4 +1,5 @@
 config CAN_M_CAN
+	depends on HAS_IOMEM
 	tristate "Bosch M_CAN devices"
 	---help---
 	  Say Y here if you want to support for Bosch M_CAN controller.
diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
index 10d571eaed85..d7bc462aafdc 100644
--- a/drivers/net/can/m_can/m_can.c
+++ b/drivers/net/can/m_can/m_can.c
@@ -105,14 +105,36 @@ enum m_can_mram_cfg {
 	MRAM_CFG_NUM,
 };
 
+/* Fast Bit Timing & Prescaler Register (FBTP) */
+#define FBTR_FBRP_MASK		0x1f
+#define FBTR_FBRP_SHIFT		16
+#define FBTR_FTSEG1_SHIFT	8
+#define FBTR_FTSEG1_MASK	(0xf << FBTR_FTSEG1_SHIFT)
+#define FBTR_FTSEG2_SHIFT	4
+#define FBTR_FTSEG2_MASK	(0x7 << FBTR_FTSEG2_SHIFT)
+#define FBTR_FSJW_SHIFT		0
+#define FBTR_FSJW_MASK		0x3
+
 /* Test Register (TEST) */
 #define TEST_LBCK	BIT(4)
 
 /* CC Control Register(CCCR) */
-#define CCCR_TEST	BIT(7)
-#define CCCR_MON	BIT(5)
-#define CCCR_CCE	BIT(1)
-#define CCCR_INIT	BIT(0)
+#define CCCR_TEST		BIT(7)
+#define CCCR_CMR_MASK		0x3
+#define CCCR_CMR_SHIFT		10
+#define CCCR_CMR_CANFD		0x1
+#define CCCR_CMR_CANFD_BRS	0x2
+#define CCCR_CMR_CAN		0x3
+#define CCCR_CME_MASK		0x3
+#define CCCR_CME_SHIFT		8
+#define CCCR_CME_CAN		0
+#define CCCR_CME_CANFD		0x1
+#define CCCR_CME_CANFD_BRS	0x2
+#define CCCR_TEST		BIT(7)
+#define CCCR_MON		BIT(5)
+#define CCCR_CCE		BIT(1)
+#define CCCR_INIT		BIT(0)
+#define CCCR_CANFD		0x10
 
 /* Bit Timing & Prescaler Register (BTP) */
 #define BTR_BRP_MASK		0x3ff
@@ -204,6 +226,7 @@ enum m_can_mram_cfg {
 
 /* Rx Buffer / FIFO Element Size Configuration (RXESC) */
 #define M_CAN_RXESC_8BYTES	0x0
+#define M_CAN_RXESC_64BYTES	0x777
 
 /* Tx Buffer Configuration(TXBC) */
 #define TXBC_NDTB_OFF		16
@@ -211,6 +234,7 @@ enum m_can_mram_cfg {
 
 /* Tx Buffer Element Size Configuration(TXESC) */
 #define TXESC_TBDS_8BYTES	0x0
+#define TXESC_TBDS_64BYTES	0x7
 
 /* Tx Event FIFO Con.guration (TXEFC) */
 #define TXEFC_EFS_OFF		16
@@ -219,11 +243,11 @@ enum m_can_mram_cfg {
 /* Message RAM Configuration (in bytes) */
 #define SIDF_ELEMENT_SIZE	4
 #define XIDF_ELEMENT_SIZE	8
-#define RXF0_ELEMENT_SIZE	16
-#define RXF1_ELEMENT_SIZE	16
+#define RXF0_ELEMENT_SIZE	72
+#define RXF1_ELEMENT_SIZE	72
 #define RXB_ELEMENT_SIZE	16
 #define TXE_ELEMENT_SIZE	8
-#define TXB_ELEMENT_SIZE	16
+#define TXB_ELEMENT_SIZE	72
 
 /* Message RAM Elements */
 #define M_CAN_FIFO_ID		0x0
@@ -231,11 +255,17 @@ enum m_can_mram_cfg {
 #define M_CAN_FIFO_DATA(n)	(0x8 + ((n) << 2))
 
 /* Rx Buffer Element */
+/* R0 */
 #define RX_BUF_ESI		BIT(31)
 #define RX_BUF_XTD		BIT(30)
 #define RX_BUF_RTR		BIT(29)
+/* R1 */
+#define RX_BUF_ANMF		BIT(31)
+#define RX_BUF_EDL		BIT(21)
+#define RX_BUF_BRS		BIT(20)
 
 /* Tx Buffer Element */
+/* R0 */
 #define TX_BUF_XTD		BIT(30)
 #define TX_BUF_RTR		BIT(29)
 
@@ -296,6 +326,7 @@ static inline void m_can_config_endisable(const struct m_can_priv *priv,
 	if (enable) {
 		/* enable m_can configuration */
 		m_can_write(priv, M_CAN_CCCR, cccr | CCCR_INIT);
+		udelay(5);
 		/* CCCR.CCE can only be set/reset while CCCR.INIT = '1' */
 		m_can_write(priv, M_CAN_CCCR, cccr | CCCR_INIT | CCCR_CCE);
 	} else {
@@ -326,41 +357,67 @@ static inline void m_can_disable_all_interrupts(const struct m_can_priv *priv)
 	m_can_write(priv, M_CAN_ILE, 0x0);
 }
 
-static void m_can_read_fifo(const struct net_device *dev, struct can_frame *cf,
-			    u32 rxfs)
+static void m_can_read_fifo(struct net_device *dev, u32 rxfs)
 {
+	struct net_device_stats *stats = &dev->stats;
 	struct m_can_priv *priv = netdev_priv(dev);
-	u32 id, fgi;
+	struct canfd_frame *cf;
+	struct sk_buff *skb;
+	u32 id, fgi, dlc;
+	int i;
 
 	/* calculate the fifo get index for where to read data */
 	fgi = (rxfs & RXFS_FGI_MASK) >> RXFS_FGI_OFF;
+	dlc = m_can_fifo_read(priv, fgi, M_CAN_FIFO_DLC);
+	if (dlc & RX_BUF_EDL)
+		skb = alloc_canfd_skb(dev, &cf);
+	else
+		skb = alloc_can_skb(dev, (struct can_frame **)&cf);
+	if (!skb) {
+		stats->rx_dropped++;
+		return;
+	}
+
+	if (dlc & RX_BUF_EDL)
+		cf->len = can_dlc2len((dlc >> 16) & 0x0F);
+	else
+		cf->len = get_can_dlc((dlc >> 16) & 0x0F);
+
 	id = m_can_fifo_read(priv, fgi, M_CAN_FIFO_ID);
 	if (id & RX_BUF_XTD)
 		cf->can_id = (id & CAN_EFF_MASK) | CAN_EFF_FLAG;
 	else
 		cf->can_id = (id >> 18) & CAN_SFF_MASK;
 
-	if (id & RX_BUF_RTR) {
+	if (id & RX_BUF_ESI) {
+		cf->flags |= CANFD_ESI;
+		netdev_dbg(dev, "ESI Error\n");
+	}
+
+	if (!(dlc & RX_BUF_EDL) && (id & RX_BUF_RTR)) {
 		cf->can_id |= CAN_RTR_FLAG;
 	} else {
-		id = m_can_fifo_read(priv, fgi, M_CAN_FIFO_DLC);
-		cf->can_dlc = get_can_dlc((id >> 16) & 0x0F);
-		*(u32 *)(cf->data + 0) = m_can_fifo_read(priv, fgi,
-							 M_CAN_FIFO_DATA(0));
-		*(u32 *)(cf->data + 4) = m_can_fifo_read(priv, fgi,
-							 M_CAN_FIFO_DATA(1));
+		if (dlc & RX_BUF_BRS)
+			cf->flags |= CANFD_BRS;
+
+		for (i = 0; i < cf->len; i += 4)
+			*(u32 *)(cf->data + i) =
+				m_can_fifo_read(priv, fgi,
+						M_CAN_FIFO_DATA(i / 4));
 	}
 
 	/* acknowledge rx fifo 0 */
 	m_can_write(priv, M_CAN_RXF0A, fgi);
+
+	stats->rx_packets++;
+	stats->rx_bytes += cf->len;
+
+	netif_receive_skb(skb);
 }
 
 static int m_can_do_rx_poll(struct net_device *dev, int quota)
 {
 	struct m_can_priv *priv = netdev_priv(dev);
-	struct net_device_stats *stats = &dev->stats;
-	struct sk_buff *skb;
-	struct can_frame *frame;
 	u32 pkts = 0;
 	u32 rxfs;
 
@@ -374,18 +431,7 @@ static int m_can_do_rx_poll(struct net_device *dev, int quota)
 		if (rxfs & RXFS_RFL)
 			netdev_warn(dev, "Rx FIFO 0 Message Lost\n");
 
-		skb = alloc_can_skb(dev, &frame);
-		if (!skb) {
-			stats->rx_dropped++;
-			return pkts;
-		}
-
-		m_can_read_fifo(dev, frame, rxfs);
-
-		stats->rx_packets++;
-		stats->rx_bytes += frame->can_dlc;
-
-		netif_receive_skb(skb);
+		m_can_read_fifo(dev, rxfs);
 
 		quota--;
 		pkts++;
@@ -481,11 +527,23 @@ static int m_can_handle_lec_err(struct net_device *dev,
 	return 1;
 }
 
+static int __m_can_get_berr_counter(const struct net_device *dev,
+				    struct can_berr_counter *bec)
+{
+	struct m_can_priv *priv = netdev_priv(dev);
+	unsigned int ecr;
+
+	ecr = m_can_read(priv, M_CAN_ECR);
+	bec->rxerr = (ecr & ECR_REC_MASK) >> ECR_REC_SHIFT;
+	bec->txerr = ecr & ECR_TEC_MASK;
+
+	return 0;
+}
+
 static int m_can_get_berr_counter(const struct net_device *dev,
 				  struct can_berr_counter *bec)
 {
 	struct m_can_priv *priv = netdev_priv(dev);
-	unsigned int ecr;
 	int err;
 
 	err = clk_prepare_enable(priv->hclk);
@@ -498,9 +556,7 @@ static int m_can_get_berr_counter(const struct net_device *dev,
 		return err;
 	}
 
-	ecr = m_can_read(priv, M_CAN_ECR);
-	bec->rxerr = (ecr & ECR_REC_MASK) >> ECR_REC_SHIFT;
-	bec->txerr = ecr & ECR_TEC_MASK;
+	__m_can_get_berr_counter(dev, bec);
 
 	clk_disable_unprepare(priv->cclk);
 	clk_disable_unprepare(priv->hclk);
@@ -544,7 +600,7 @@ static int m_can_handle_state_change(struct net_device *dev,
 	if (unlikely(!skb))
 		return 0;
 
-	m_can_get_berr_counter(dev, &bec);
+	__m_can_get_berr_counter(dev, &bec);
 
 	switch (new_state) {
 	case CAN_STATE_ERROR_ACTIVE:
@@ -596,14 +652,14 @@ static int m_can_handle_state_errors(struct net_device *dev, u32 psr)
 
 	if ((psr & PSR_EP) &&
 	    (priv->can.state != CAN_STATE_ERROR_PASSIVE)) {
-		netdev_dbg(dev, "entered error warning state\n");
+		netdev_dbg(dev, "entered error passive state\n");
 		work_done += m_can_handle_state_change(dev,
 						       CAN_STATE_ERROR_PASSIVE);
 	}
 
 	if ((psr & PSR_BO) &&
 	    (priv->can.state != CAN_STATE_BUS_OFF)) {
-		netdev_dbg(dev, "entered error warning state\n");
+		netdev_dbg(dev, "entered error bus off state\n");
 		work_done += m_can_handle_state_change(dev,
 						       CAN_STATE_BUS_OFF);
 	}
@@ -615,7 +671,7 @@ static void m_can_handle_other_err(struct net_device *dev, u32 irqstatus)
 {
 	if (irqstatus & IR_WDI)
 		netdev_err(dev, "Message RAM Watchdog event due to missing READY\n");
-	if (irqstatus & IR_BEU)
+	if (irqstatus & IR_ELO)
 		netdev_err(dev, "Error Logging Overflow\n");
 	if (irqstatus & IR_BEU)
 		netdev_err(dev, "Bit Error Uncorrected\n");
@@ -733,10 +789,23 @@ static const struct can_bittiming_const m_can_bittiming_const = {
 	.brp_inc = 1,
 };
 
+static const struct can_bittiming_const m_can_data_bittiming_const = {
+	.name = KBUILD_MODNAME,
+	.tseg1_min = 2,		/* Time segment 1 = prop_seg + phase_seg1 */
+	.tseg1_max = 16,
+	.tseg2_min = 1,		/* Time segment 2 = phase_seg2 */
+	.tseg2_max = 8,
+	.sjw_max = 4,
+	.brp_min = 1,
+	.brp_max = 32,
+	.brp_inc = 1,
+};
+
 static int m_can_set_bittiming(struct net_device *dev)
 {
 	struct m_can_priv *priv = netdev_priv(dev);
 	const struct can_bittiming *bt = &priv->can.bittiming;
+	const struct can_bittiming *dbt = &priv->can.data_bittiming;
 	u16 brp, sjw, tseg1, tseg2;
 	u32 reg_btp;
 
@@ -747,7 +816,17 @@ static int m_can_set_bittiming(struct net_device *dev)
 	reg_btp = (brp << BTR_BRP_SHIFT) | (sjw << BTR_SJW_SHIFT) |
 			(tseg1 << BTR_TSEG1_SHIFT) | (tseg2 << BTR_TSEG2_SHIFT);
 	m_can_write(priv, M_CAN_BTP, reg_btp);
-	netdev_dbg(dev, "setting BTP 0x%x\n", reg_btp);
+
+	if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {
+		brp = dbt->brp - 1;
+		sjw = dbt->sjw - 1;
+		tseg1 = dbt->prop_seg + dbt->phase_seg1 - 1;
+		tseg2 = dbt->phase_seg2 - 1;
+		reg_btp = (brp << FBTR_FBRP_SHIFT) | (sjw << FBTR_FSJW_SHIFT) |
+				(tseg1 << FBTR_FTSEG1_SHIFT) |
+				(tseg2 << FBTR_FTSEG2_SHIFT);
+		m_can_write(priv, M_CAN_FBTP, reg_btp);
+	}
 
 	return 0;
 }
@@ -767,8 +846,8 @@ static void m_can_chip_config(struct net_device *dev)
 
 	m_can_config_endisable(priv, true);
 
-	/* RX Buffer/FIFO Element Size 8 bytes data field */
-	m_can_write(priv, M_CAN_RXESC, M_CAN_RXESC_8BYTES);
+	/* RX Buffer/FIFO Element Size 64 bytes data field */
+	m_can_write(priv, M_CAN_RXESC, M_CAN_RXESC_64BYTES);
 
 	/* Accept Non-matching Frames Into FIFO 0 */
 	m_can_write(priv, M_CAN_GFC, 0x0);
@@ -777,8 +856,8 @@ static void m_can_chip_config(struct net_device *dev)
 	m_can_write(priv, M_CAN_TXBC, (1 << TXBC_NDTB_OFF) |
 		    priv->mcfg[MRAM_TXB].off);
 
-	/* only support 8 bytes firstly */
-	m_can_write(priv, M_CAN_TXESC, TXESC_TBDS_8BYTES);
+	/* support 64 bytes payload */
+	m_can_write(priv, M_CAN_TXESC, TXESC_TBDS_64BYTES);
 
 	m_can_write(priv, M_CAN_TXEFC, (1 << TXEFC_EFS_OFF) |
 		    priv->mcfg[MRAM_TXE].off);
@@ -793,7 +872,8 @@ static void m_can_chip_config(struct net_device *dev)
 		    RXFC_FWM_1 | priv->mcfg[MRAM_RXF1].off);
 
 	cccr = m_can_read(priv, M_CAN_CCCR);
-	cccr &= ~(CCCR_TEST | CCCR_MON);
+	cccr &= ~(CCCR_TEST | CCCR_MON | (CCCR_CMR_MASK << CCCR_CMR_SHIFT) |
+		(CCCR_CME_MASK << CCCR_CME_SHIFT));
 	test = m_can_read(priv, M_CAN_TEST);
 	test &= ~TEST_LBCK;
 
@@ -805,6 +885,9 @@ static void m_can_chip_config(struct net_device *dev)
 		test |= TEST_LBCK;
 	}
 
+	if (priv->can.ctrlmode & CAN_CTRLMODE_FD)
+		cccr |= CCCR_CME_CANFD_BRS << CCCR_CME_SHIFT;
+
 	m_can_write(priv, M_CAN_CCCR, cccr);
 	m_can_write(priv, M_CAN_TEST, test);
 
@@ -869,11 +952,13 @@ static struct net_device *alloc_m_can_dev(void)
 
 	priv->dev = dev;
 	priv->can.bittiming_const = &m_can_bittiming_const;
+	priv->can.data_bittiming_const = &m_can_data_bittiming_const;
 	priv->can.do_set_mode = m_can_set_mode;
 	priv->can.do_get_berr_counter = m_can_get_berr_counter;
 	priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
 					CAN_CTRLMODE_LISTENONLY |
-					CAN_CTRLMODE_BERR_REPORTING;
+					CAN_CTRLMODE_BERR_REPORTING |
+					CAN_CTRLMODE_FD;
 
 	return dev;
 }
@@ -956,8 +1041,9 @@ static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
 				    struct net_device *dev)
 {
 	struct m_can_priv *priv = netdev_priv(dev);
-	struct can_frame *cf = (struct can_frame *)skb->data;
-	u32 id;
+	struct canfd_frame *cf = (struct canfd_frame *)skb->data;
+	u32 id, cccr;
+	int i;
 
 	if (can_dropped_invalid_skb(dev, skb))
 		return NETDEV_TX_OK;
@@ -976,11 +1062,28 @@ static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
 
 	/* message ram configuration */
 	m_can_fifo_write(priv, 0, M_CAN_FIFO_ID, id);
-	m_can_fifo_write(priv, 0, M_CAN_FIFO_DLC, cf->can_dlc << 16);
-	m_can_fifo_write(priv, 0, M_CAN_FIFO_DATA(0), *(u32 *)(cf->data + 0));
-	m_can_fifo_write(priv, 0, M_CAN_FIFO_DATA(1), *(u32 *)(cf->data + 4));
+	m_can_fifo_write(priv, 0, M_CAN_FIFO_DLC, can_len2dlc(cf->len) << 16);
+
+	for (i = 0; i < cf->len; i += 4)
+		m_can_fifo_write(priv, 0, M_CAN_FIFO_DATA(i / 4),
+				 *(u32 *)(cf->data + i));
+
 	can_put_echo_skb(skb, dev, 0);
 
+	if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {
+		cccr = m_can_read(priv, M_CAN_CCCR);
+		cccr &= ~(CCCR_CMR_MASK << CCCR_CMR_SHIFT);
+		if (can_is_canfd_skb(skb)) {
+			if (cf->flags & CANFD_BRS)
+				cccr |= CCCR_CMR_CANFD_BRS << CCCR_CMR_SHIFT;
+			else
+				cccr |= CCCR_CMR_CANFD << CCCR_CMR_SHIFT;
+		} else {
+			cccr |= CCCR_CMR_CAN << CCCR_CMR_SHIFT;
+		}
+		m_can_write(priv, M_CAN_CCCR, cccr);
+	}
+
 	/* enable first TX buffer to start transfer  */
 	m_can_write(priv, M_CAN_TXBTIE, 0x1);
 	m_can_write(priv, M_CAN_TXBAR, 0x1);
@@ -992,6 +1095,7 @@ static const struct net_device_ops m_can_netdev_ops = {
 	.ndo_open = m_can_open,
 	.ndo_stop = m_can_close,
 	.ndo_start_xmit = m_can_start_xmit,
+	.ndo_change_mtu = can_change_mtu,
 };
 
 static int register_m_can_dev(struct net_device *dev)
@@ -1009,7 +1113,7 @@ static int m_can_of_parse_mram(struct platform_device *pdev,
 	struct resource *res;
 	void __iomem *addr;
 	u32 out_val[MRAM_CFG_LEN];
-	int ret;
+	int i, start, end, ret;
 
 	/* message ram could be shared */
 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "message_ram");
@@ -1060,6 +1164,15 @@ static int m_can_of_parse_mram(struct platform_device *pdev,
 		priv->mcfg[MRAM_TXE].off, priv->mcfg[MRAM_TXE].num,
 		priv->mcfg[MRAM_TXB].off, priv->mcfg[MRAM_TXB].num);
 
+	/* initialize the entire Message RAM in use to avoid possible
+	 * ECC/parity checksum errors when reading an uninitialized buffer
+	 */
+	start = priv->mcfg[MRAM_SIDF].off;
+	end = priv->mcfg[MRAM_TXB].off +
+		priv->mcfg[MRAM_TXB].num * TXB_ELEMENT_SIZE;
+	for (i = start; i < end; i += 4)
+		writel(0x0, priv->mram_base + i);
+
 	return 0;
 }
 
diff --git a/drivers/net/can/rcar_can.c b/drivers/net/can/rcar_can.c
index 1abe133d1594..9718248e55f1 100644
--- a/drivers/net/can/rcar_can.c
+++ b/drivers/net/can/rcar_can.c
@@ -628,6 +628,7 @@ static const struct net_device_ops rcar_can_netdev_ops = {
 	.ndo_open = rcar_can_open,
 	.ndo_stop = rcar_can_close,
 	.ndo_start_xmit = rcar_can_start_xmit,
+	.ndo_change_mtu = can_change_mtu,
 };
 
 static void rcar_can_rx_pkt(struct rcar_can_priv *priv)
diff --git a/drivers/net/can/sja1000/kvaser_pci.c b/drivers/net/can/sja1000/kvaser_pci.c
index 8ff3424d5147..15c00faeec61 100644
--- a/drivers/net/can/sja1000/kvaser_pci.c
+++ b/drivers/net/can/sja1000/kvaser_pci.c
@@ -214,7 +214,7 @@ static int kvaser_pci_add_chan(struct pci_dev *pdev, int channel,
 	struct net_device *dev;
 	struct sja1000_priv *priv;
 	struct kvaser_pci *board;
-	int err, init_step;
+	int err;
 
 	dev = alloc_sja1000dev(sizeof(struct kvaser_pci));
 	if (dev == NULL)
@@ -235,7 +235,6 @@ static int kvaser_pci_add_chan(struct pci_dev *pdev, int channel,
 	if (channel == 0) {
 		board->xilinx_ver =
 			ioread8(board->res_addr + XILINX_VERINT) >> 4;
-		init_step = 2;
 
 		/* Assert PTADR# - we're in passive mode so the other bits are
 		   not important */
@@ -264,8 +263,6 @@ static int kvaser_pci_add_chan(struct pci_dev *pdev, int channel,
 	priv->irq_flags = IRQF_SHARED;
 	dev->irq = pdev->irq;
 
-	init_step = 4;
-
 	dev_info(&pdev->dev, "reg_base=%p conf_addr=%p irq=%d\n",
 		 priv->reg_base, board->conf_addr, dev->irq);
 
diff --git a/drivers/net/can/usb/ems_usb.c b/drivers/net/can/usb/ems_usb.c
index 00f2534dde73..29d3f0938eb8 100644
--- a/drivers/net/can/usb/ems_usb.c
+++ b/drivers/net/can/usb/ems_usb.c
@@ -434,10 +434,9 @@ static void ems_usb_read_bulk_callback(struct urb *urb)
 	if (urb->actual_length > CPC_HEADER_SIZE) {
 		struct ems_cpc_msg *msg;
 		u8 *ibuf = urb->transfer_buffer;
-		u8 msg_count, again, start;
+		u8 msg_count, start;
 
 		msg_count = ibuf[0] & ~0x80;
-		again = ibuf[0] & 0x80;
 
 		start = CPC_HEADER_SIZE;
 
diff --git a/drivers/net/can/usb/esd_usb2.c b/drivers/net/can/usb/esd_usb2.c
index b7c9e8b11460..c063a54ab8dd 100644
--- a/drivers/net/can/usb/esd_usb2.c
+++ b/drivers/net/can/usb/esd_usb2.c
@@ -464,7 +464,6 @@ static void esd_usb2_write_bulk_callback(struct urb *urb)
 {
 	struct esd_tx_urb_context *context = urb->context;
 	struct esd_usb2_net_priv *priv;
-	struct esd_usb2 *dev;
 	struct net_device *netdev;
 	size_t size = sizeof(struct esd_usb2_msg);
 
@@ -472,7 +471,6 @@ static void esd_usb2_write_bulk_callback(struct urb *urb)
 
 	priv = context->priv;
 	netdev = priv->netdev;
-	dev = priv->usb2;
 
 	/* free up our allocated buffer */
 	usb_free_coherent(urb->dev, size,
@@ -1143,6 +1141,7 @@ static void esd_usb2_disconnect(struct usb_interface *intf)
 			}
 		}
 		unlink_all_urbs(dev);
+		kfree(dev);
 	}
 }
 
diff --git a/drivers/net/can/usb/gs_usb.c b/drivers/net/can/usb/gs_usb.c
index 04b0f84612f0..009acc8641fc 100644
--- a/drivers/net/can/usb/gs_usb.c
+++ b/drivers/net/can/usb/gs_usb.c
@@ -718,6 +718,7 @@ static const struct net_device_ops gs_usb_netdev_ops = {
 	.ndo_open = gs_can_open,
 	.ndo_stop = gs_can_close,
 	.ndo_start_xmit = gs_can_start_xmit,
+	.ndo_change_mtu = can_change_mtu,
 };
 
 static struct gs_can *gs_make_candev(unsigned int channel, struct usb_interface *intf)
diff --git a/drivers/net/can/xilinx_can.c b/drivers/net/can/xilinx_can.c
index 5e8b5609c067..8a998e3884ce 100644
--- a/drivers/net/can/xilinx_can.c
+++ b/drivers/net/can/xilinx_can.c
@@ -300,7 +300,8 @@ static int xcan_set_bittiming(struct net_device *ndev)
 static int xcan_chip_start(struct net_device *ndev)
 {
 	struct xcan_priv *priv = netdev_priv(ndev);
-	u32 err, reg_msr, reg_sr_mask;
+	u32 reg_msr, reg_sr_mask;
+	int err;
 	unsigned long timeout;
 
 	/* Check if it is in reset mode */
@@ -961,6 +962,7 @@ static const struct net_device_ops xcan_netdev_ops = {
 	.ndo_open	= xcan_open,
 	.ndo_stop	= xcan_close,
 	.ndo_start_xmit	= xcan_start_xmit,
+	.ndo_change_mtu	= can_change_mtu,
 };
 
 /**
diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h
index 6992afc6ba7f..b37ea95bc348 100644
--- a/include/linux/can/dev.h
+++ b/include/linux/can/dev.h
@@ -99,6 +99,12 @@ inval_skb:
 	return 1;
 }
 
+static inline bool can_is_canfd_skb(const struct sk_buff *skb)
+{
+	/* the CAN specific type of skb is identified by its data length */
+	return skb->len == CANFD_MTU;
+}
+
 /* get data length from can_dlc with sanitized can_dlc */
 u8 can_dlc2len(u8 can_dlc);