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>

9 files changed, 177 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,
 };
 
 /**