Subject: Re: [PATCH v4] can: kvaser_usb: Add support for Kvaser CAN/USB devices

From: Wolfgang Grandegger <[email-masked]>
Date: Sat, 22 Sep 2012 18:02:14 +0200

On 09/21/2012 11:54 AM, Marc Kleine-Budde wrote:
> On 09/20/2012 07:06 AM, Olivier Sobrie wrote:
>> This driver provides support for several Kvaser CAN/USB devices.
>> Such kind of devices supports up to three CAN network interfaces.
>>
>> It has been tested with a Kvaser USB Leaf Light (one network interface)
>> connected to a pch_can interface.
>> The firmware version of the Kvaser device was 2.5.205.
> 
> I don't remember, have the USB people already had a look on your driver
> and gave some comments?

IIRC, Oliver Neukum commented on v2. Actually we ignored v3 :(, sorry!

> From the CAN and network point of view looks good, some comments inline.
> Would be fine, if Wolfgang can give comments or Ack about the error
> frame generation.

Olivier already sent candump traces for no cable connected and
short-circuiting CAN high and low. The error handling looked good, IIRC,
at least as good as the firmware can do... more comments inline...

>> List of Kvaser devices supported by the driver:
>>   - Kvaser Leaf prototype (P010v2 and v3)
>>   - Kvaser Leaf Light (P010v3)
>>   - Kvaser Leaf Professional HS
>>   - Kvaser Leaf SemiPro HS
>>   - Kvaser Leaf Professional LS
>>   - Kvaser Leaf Professional SWC
>>   - Kvaser Leaf Professional LIN
>>   - Kvaser Leaf SemiPro LS
>>   - Kvaser Leaf SemiPro SWC
>>   - Kvaser Memorator II, Prototype
>>   - Kvaser Memorator II HS/HS
>>   - Kvaser USBcan Professional HS/HS
>>   - Kvaser Leaf Light GI
>>   - Kvaser Leaf Professional HS (OBD-II connector)
>>   - Kvaser Memorator Professional HS/LS
>>   - Kvaser Leaf Light "China"
>>   - Kvaser BlackBird SemiPro
>>   - Kvaser OEM Mercury
>>   - Kvaser OEM Leaf
>>   - Kvaser USBcan R
>>
>> Signed-off-by: Olivier Sobrie <[email-masked]>
>> ---
>> Changes since v3:
>>  - add support for CMD_LOG_MESSAGE
>>
>>  drivers/net/can/usb/Kconfig      |   33 +
>>  drivers/net/can/usb/Makefile     |    1 +
>>  drivers/net/can/usb/kvaser_usb.c | 1555 ++++++++++++++++++++++++++++++++++++++
>>  3 files changed, 1589 insertions(+)
>>  create mode 100644 drivers/net/can/usb/kvaser_usb.c
>>
>> diff --git a/drivers/net/can/usb/Kconfig b/drivers/net/can/usb/Kconfig
>> index 0a68768..578955f 100644
>> --- a/drivers/net/can/usb/Kconfig
>> +++ b/drivers/net/can/usb/Kconfig
>> @@ -13,6 +13,39 @@ config CAN_ESD_USB2
>>            This driver supports the CAN-USB/2 interface
>>            from esd electronic system design gmbh (http://www.esd.eu).
>>  
>> +config CAN_KVASER_USB
>> +	tristate "Kvaser CAN/USB interface"
>> +	---help---
>> +	  This driver adds support for Kvaser CAN/USB devices like Kvaser
>> +	  Leaf Light.
>> +
>> +	  The driver gives support for the following devices:
>> +	    - Kvaser Leaf prototype (P010v2 and v3)
>> +	    - Kvaser Leaf Light (P010v3)
>> +	    - Kvaser Leaf Professional HS
>> +	    - Kvaser Leaf SemiPro HS
>> +	    - Kvaser Leaf Professional LS
>> +	    - Kvaser Leaf Professional SWC
>> +	    - Kvaser Leaf Professional LIN
>> +	    - Kvaser Leaf SemiPro LS
>> +	    - Kvaser Leaf SemiPro SWC
>> +	    - Kvaser Memorator II, Prototype
>> +	    - Kvaser Memorator II HS/HS
>> +	    - Kvaser USBcan Professional HS/HS
>> +	    - Kvaser Leaf Light GI
>> +	    - Kvaser Leaf Professional HS (OBD-II connector)
>> +	    - Kvaser Memorator Professional HS/LS
>> +	    - Kvaser Leaf Light "China"
>> +	    - Kvaser BlackBird SemiPro
>> +	    - Kvaser OEM Mercury
>> +	    - Kvaser OEM Leaf
>> +	    - Kvaser USBcan R
>> +
>> +	  If unsure, say N.
>> +
>> +	  To compile this driver as a module, choose M here: the
>> +	  module will be called kvaser_usb.
>> +
>>  config CAN_PEAK_USB
>>  	tristate "PEAK PCAN-USB/USB Pro interfaces"
>>  	---help---
>> diff --git a/drivers/net/can/usb/Makefile b/drivers/net/can/usb/Makefile
>> index da6d1d3..80a2ee4 100644
>> --- a/drivers/net/can/usb/Makefile
>> +++ b/drivers/net/can/usb/Makefile
>> @@ -4,6 +4,7 @@
>>  
>>  obj-$(CONFIG_CAN_EMS_USB) += ems_usb.o
>>  obj-$(CONFIG_CAN_ESD_USB2) += esd_usb2.o
>> +obj-$(CONFIG_CAN_KVASER_USB) += kvaser_usb.o
>>  obj-$(CONFIG_CAN_PEAK_USB) += peak_usb/
>>  
>>  ccflags-$(CONFIG_CAN_DEBUG_DEVICES) := -DDEBUG
>> diff --git a/drivers/net/can/usb/kvaser_usb.c b/drivers/net/can/usb/kvaser_usb.c
>> new file mode 100644
>> index 0000000..3509ca5
>> --- /dev/null
>> +++ b/drivers/net/can/usb/kvaser_usb.c
>> @@ -0,0 +1,1555 @@
>> +/*
>> + * This program is free software; you can redistribute it and/or
>> + * modify it under the terms of the GNU General Public License as
>> + * published by the Free Software Foundation version 2.
>> + *
>> + * Parts of this driver are based on the following:
>> + *  - Kvaser linux leaf driver (version 4.78)
>> + *  - CAN driver for esd CAN-USB/2
>> + *
>> + * Copyright (C) 2002-2006 KVASER AB, Sweden. All rights reserved.
>> + * Copyright (C) 2010 Matthias Fuchs <[email-masked]>, esd gmbh
>> + * Copyright (C) 2012 Olivier Sobrie <[email-masked]>
>> + */
>> +
>> +#include <linux/init.h>
>> +#include <linux/completion.h>
>> +#include <linux/module.h>
>> +#include <linux/netdevice.h>
>> +#include <linux/usb.h>
>> +
>> +#include <linux/can.h>
>> +#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 */
>> +#define USB_SEND_TIMEOUT		1000 /* msecs */
>> +#define USB_RECV_TIMEOUT		1000 /* msecs */
>> +#define RX_BUFFER_SIZE			3072
>> +#define CAN_USB_CLOCK			8000000
>> +#define MAX_NET_DEVICES			3
>> +
>> +/* Kvaser USB devices */
>> +#define KVASER_VENDOR_ID		0x0bfd
>> +#define USB_LEAF_DEVEL_PRODUCT_ID	10
>> +#define USB_LEAF_LITE_PRODUCT_ID	11
>> +#define USB_LEAF_PRO_PRODUCT_ID		12
>> +#define USB_LEAF_SPRO_PRODUCT_ID	14
>> +#define USB_LEAF_PRO_LS_PRODUCT_ID	15
>> +#define USB_LEAF_PRO_SWC_PRODUCT_ID	16
>> +#define USB_LEAF_PRO_LIN_PRODUCT_ID	17
>> +#define USB_LEAF_SPRO_LS_PRODUCT_ID	18
>> +#define USB_LEAF_SPRO_SWC_PRODUCT_ID	19
>> +#define USB_MEMO2_DEVEL_PRODUCT_ID	22
>> +#define USB_MEMO2_HSHS_PRODUCT_ID	23
>> +#define USB_UPRO_HSHS_PRODUCT_ID	24
>> +#define USB_LEAF_LITE_GI_PRODUCT_ID	25
>> +#define USB_LEAF_PRO_OBDII_PRODUCT_ID	26
>> +#define USB_MEMO2_HSLS_PRODUCT_ID	27
>> +#define USB_LEAF_LITE_CH_PRODUCT_ID	28
>> +#define USB_BLACKBIRD_SPRO_PRODUCT_ID	29
>> +#define USB_OEM_MERCURY_PRODUCT_ID	34
>> +#define USB_OEM_LEAF_PRODUCT_ID		35
>> +#define USB_CAN_R_PRODUCT_ID		39
>> +
>> +/* USB devices features */
>> +#define KVASER_HAS_SILENT_MODE		BIT(0)
>> +#define KVASER_HAS_TXRX_ERRORS		BIT(1)
>> +
>> +/* Message header size */
>> +#define MSG_HEADER_LEN			2
>> +
>> +/* Can message flags */
>> +#define MSG_FLAG_ERROR_FRAME		BIT(0)
>> +#define MSG_FLAG_OVERRUN		BIT(1)
>> +#define MSG_FLAG_NERR			BIT(2)
>> +#define MSG_FLAG_WAKEUP			BIT(3)
>> +#define MSG_FLAG_REMOTE_FRAME		BIT(4)
>> +#define MSG_FLAG_RESERVED		BIT(5)
>> +#define MSG_FLAG_TX_ACK			BIT(6)
>> +#define MSG_FLAG_TX_REQUEST		BIT(7)
>> +
>> +/* Can states */
>> +#define M16C_STATE_BUS_RESET		BIT(0)
>> +#define M16C_STATE_BUS_ERROR		BIT(4)
>> +#define M16C_STATE_BUS_PASSIVE		BIT(5)
>> +#define M16C_STATE_BUS_OFF		BIT(6)
>> +
>> +/* Can msg ids */
>> +#define CMD_RX_STD_MESSAGE		12
>> +#define CMD_TX_STD_MESSAGE		13
>> +#define CMD_RX_EXT_MESSAGE		14
>> +#define CMD_TX_EXT_MESSAGE		15
>> +#define CMD_SET_BUS_PARAMS		16
>> +#define CMD_GET_BUS_PARAMS		17
>> +#define CMD_GET_BUS_PARAMS_REPLY	18
>> +#define CMD_GET_CHIP_STATE		19
>> +#define CMD_CHIP_STATE_EVENT		20
>> +#define CMD_SET_CTRL_MODE		21
>> +#define CMD_GET_CTRL_MODE		22
>> +#define CMD_GET_CTRL_MODE_REPLY		23
>> +#define CMD_RESET_CHIP			24
>> +#define CMD_RESET_CARD			25
>> +#define CMD_START_CHIP			26
>> +#define CMD_START_CHIP_REPLY		27
>> +#define CMD_STOP_CHIP			28
>> +#define CMD_STOP_CHIP_REPLY		29
>> +#define CMD_GET_CARD_INFO2		32
>> +#define CMD_GET_CARD_INFO		34
>> +#define CMD_GET_CARD_INFO_REPLY		35
>> +#define CMD_GET_SOFTWARE_INFO		38
>> +#define CMD_GET_SOFTWARE_INFO_REPLY	39
>> +#define CMD_ERROR_EVENT			45
>> +#define CMD_FLUSH_QUEUE			48
>> +#define CMD_RESET_ERROR_COUNTER		49
>> +#define CMD_TX_ACKNOWLEDGE		50
>> +#define CMD_CAN_ERROR_EVENT		51
>> +#define CMD_USB_THROTTLE		77
>> +#define CMD_LOG_MESSAGE			106
>> +
>> +/* error factors */
>> +#define M16C_EF_ACKE			BIT(0)
>> +#define M16C_EF_CRCE			BIT(1)
>> +#define M16C_EF_FORME			BIT(2)
>> +#define M16C_EF_STFE			BIT(3)
>> +#define M16C_EF_BITE0			BIT(4)
>> +#define M16C_EF_BITE1			BIT(5)
>> +#define M16C_EF_RCVE			BIT(6)
>> +#define M16C_EF_TRE			BIT(7)
>> +
>> +/* bittiming parameters */
>> +#define KVASER_USB_TSEG1_MIN		1
>> +#define KVASER_USB_TSEG1_MAX		16
>> +#define KVASER_USB_TSEG2_MIN		1
>> +#define KVASER_USB_TSEG2_MAX		8
>> +#define KVASER_USB_SJW_MAX		4
>> +#define KVASER_USB_BRP_MIN		1
>> +#define KVASER_USB_BRP_MAX		64
>> +#define KVASER_USB_BRP_INC		1
>> +
>> +/* ctrl modes */
>> +#define KVASER_CTRL_MODE_NORMAL		1
>> +#define KVASER_CTRL_MODE_SILENT		2
>> +#define KVASER_CTRL_MODE_SELFRECEPTION	3
>> +#define KVASER_CTRL_MODE_OFF		4
>> +
>> +struct kvaser_msg_simple {
>> +	u8 tid;
>> +	u8 channel;
>> +} __packed;
>> +
>> +struct kvaser_msg_cardinfo {
>> +	u8 tid;
>> +	u8 nchannels;
>> +	__le32 serial_number;
>> +	__le32 padding;
>> +	__le32 clock_resolution;
>> +	__le32 mfgdate;
>> +	u8 ean[8];
>> +	u8 hw_revision;
>> +	u8 usb_hs_mode;
>> +	__le16 padding2;
>> +} __packed;
>> +
>> +struct kvaser_msg_cardinfo2 {
>> +	u8 tid;
>> +	u8 channel;
>> +	u8 pcb_id[24];
>> +	__le32 oem_unlock_code;
>> +} __packed;
>> +
>> +struct kvaser_msg_softinfo {
>> +	u8 tid;
>> +	u8 channel;
>> +	__le32 sw_options;
>> +	__le32 fw_version;
>> +	__le16 max_outstanding_tx;
>> +	__le16 padding[9];
>> +} __packed;
>> +
>> +struct kvaser_msg_busparams {
>> +	u8 tid;
>> +	u8 channel;
>> +	__le32 bitrate;
>> +	u8 tseg1;
>> +	u8 tseg2;
>> +	u8 sjw;
>> +	u8 no_samp;
>> +} __packed;
>> +
>> +struct kvaser_msg_tx_can {
>> +	u8 channel;
>> +	u8 tid;
>> +	u8 msg[14];
>> +	u8 padding;
>> +	u8 flags;
>> +} __packed;
>> +
>> +struct kvaser_msg_rx_can {
>> +	u8 channel;
>> +	u8 flag;
>> +	__le16 time[3];
>> +	u8 msg[14];
>> +} __packed;
>> +
>> +struct kvaser_msg_chip_state_event {
>> +	u8 tid;
>> +	u8 channel;
>> +	__le16 time[3];
>> +	u8 tx_errors_count;
>> +	u8 rx_errors_count;
>> +	u8 status;
>> +	u8 padding[3];
>> +} __packed;
>> +
>> +struct kvaser_msg_tx_acknowledge {
>> +	u8 channel;
>> +	u8 tid;
>> +	__le16 time[3];
>> +	u8 flags;
>> +	u8 time_offset;
>> +} __packed;
>> +
>> +struct kvaser_msg_error_event {
>> +	u8 tid;
>> +	u8 flags;
>> +	__le16 time[3];
>> +	u8 channel;
>> +	u8 padding;
>> +	u8 tx_errors_count;
>> +	u8 rx_errors_count;
>> +	u8 status;
>> +	u8 error_factor;
>> +} __packed;
>> +
>> +struct kvaser_msg_ctrl_mode {
>> +	u8 tid;
>> +	u8 channel;
>> +	u8 ctrl_mode;
>> +	u8 padding[3];
>> +} __packed;
>> +
>> +struct kvaser_msg_flush_queue {
>> +	u8 tid;
>> +	u8 channel;
>> +	u8 flags;
>> +	u8 padding[3];
>> +} __packed;
>> +
>> +struct kvaser_msg_log_message {
>> +	u8 channel;
>> +	u8 flags;
>> +	__le16 time[3];
>> +	u8 dlc;
>> +	u8 time_offset;
>> +	__le32 id;
>> +	u8 data[8];
>> +} __packed;
>> +
>> +struct kvaser_msg {
>> +	u8 len;
>> +	u8 id;
>> +	union	{
>> +		struct kvaser_msg_simple simple;
>> +		struct kvaser_msg_cardinfo cardinfo;
>> +		struct kvaser_msg_cardinfo2 cardinfo2;
>> +		struct kvaser_msg_softinfo softinfo;
>> +		struct kvaser_msg_busparams busparams;
>> +		struct kvaser_msg_tx_can tx_can;
>> +		struct kvaser_msg_rx_can rx_can;
>> +		struct kvaser_msg_chip_state_event chip_state_event;
>> +		struct kvaser_msg_tx_acknowledge tx_acknowledge;
>> +		struct kvaser_msg_error_event error_event;
>> +		struct kvaser_msg_ctrl_mode ctrl_mode;
>> +		struct kvaser_msg_flush_queue flush_queue;
>> +		struct kvaser_msg_log_message log_message;
>> +	} u;
>> +} __packed;
>> +
>> +struct kvaser_usb_tx_urb_context {
>> +	struct kvaser_usb_net_priv *priv;
>> +	u32 echo_index;
>> +	int dlc;
>> +};
>> +
>> +struct kvaser_usb {
>> +	struct usb_device *udev;
>> +	struct kvaser_usb_net_priv *nets[MAX_NET_DEVICES];
>> +
>> +	struct usb_endpoint_descriptor *bulk_in, *bulk_out;
>> +	struct usb_anchor rx_submitted;
>> +
>> +	u32 fw_version;
>> +	unsigned int nchannels;
>> +
>> +	bool rxinitdone;
>> +	void *rxbuf[MAX_RX_URBS];
>> +	dma_addr_t rxbuf_dma[MAX_RX_URBS];
>> +};
>> +
>> +struct kvaser_usb_net_priv {
>> +	struct can_priv can;
>> +
>> +	atomic_t active_tx_urbs;
>> +	struct usb_anchor tx_submitted;
>> +	struct kvaser_usb_tx_urb_context tx_contexts[MAX_TX_URBS];
>> +
>> +	struct completion start_comp, stop_comp;
>> +
>> +	struct kvaser_usb *dev;
>> +	struct net_device *netdev;
>> +	int channel;
>> +
>> +	struct can_berr_counter bec;
>> +};
>> +
>> +static struct usb_device_id kvaser_usb_table[] = {
>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_DEVEL_PRODUCT_ID) },
>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_LITE_PRODUCT_ID) },
>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_PRO_PRODUCT_ID),
>> +		.driver_info = KVASER_HAS_TXRX_ERRORS |
>> +			       KVASER_HAS_SILENT_MODE },
>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_SPRO_PRODUCT_ID),
>> +		.driver_info = KVASER_HAS_TXRX_ERRORS |
>> +			       KVASER_HAS_SILENT_MODE },
>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_PRO_LS_PRODUCT_ID),
>> +		.driver_info = KVASER_HAS_TXRX_ERRORS |
>> +			       KVASER_HAS_SILENT_MODE },
>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_PRO_SWC_PRODUCT_ID),
>> +		.driver_info = KVASER_HAS_TXRX_ERRORS |
>> +			       KVASER_HAS_SILENT_MODE },
>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_PRO_LIN_PRODUCT_ID),
>> +		.driver_info = KVASER_HAS_TXRX_ERRORS |
>> +			       KVASER_HAS_SILENT_MODE },
>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_SPRO_LS_PRODUCT_ID),
>> +		.driver_info = KVASER_HAS_TXRX_ERRORS |
>> +			       KVASER_HAS_SILENT_MODE },
>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_SPRO_SWC_PRODUCT_ID),
>> +		.driver_info = KVASER_HAS_TXRX_ERRORS |
>> +			       KVASER_HAS_SILENT_MODE },
>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_MEMO2_DEVEL_PRODUCT_ID),
>> +		.driver_info = KVASER_HAS_TXRX_ERRORS |
>> +			       KVASER_HAS_SILENT_MODE },
>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_MEMO2_HSHS_PRODUCT_ID),
>> +		.driver_info = KVASER_HAS_TXRX_ERRORS |
>> +			       KVASER_HAS_SILENT_MODE },
>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_UPRO_HSHS_PRODUCT_ID),
>> +		.driver_info = KVASER_HAS_TXRX_ERRORS },
>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_LITE_GI_PRODUCT_ID) },
>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_PRO_OBDII_PRODUCT_ID),
>> +		.driver_info = KVASER_HAS_TXRX_ERRORS |
>> +			       KVASER_HAS_SILENT_MODE },
>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_MEMO2_HSLS_PRODUCT_ID),
>> +		.driver_info = KVASER_HAS_TXRX_ERRORS },
>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_LITE_CH_PRODUCT_ID),
>> +		.driver_info = KVASER_HAS_TXRX_ERRORS },
>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_BLACKBIRD_SPRO_PRODUCT_ID),
>> +		.driver_info = KVASER_HAS_TXRX_ERRORS },
>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_OEM_MERCURY_PRODUCT_ID),
>> +		.driver_info = KVASER_HAS_TXRX_ERRORS },
>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_OEM_LEAF_PRODUCT_ID),
>> +		.driver_info = KVASER_HAS_TXRX_ERRORS },
>> +	{ USB_DEVICE(KVASER_VENDOR_ID, USB_CAN_R_PRODUCT_ID),
>> +		.driver_info = KVASER_HAS_TXRX_ERRORS },
>> +	{ }
>> +};
>> +MODULE_DEVICE_TABLE(usb, kvaser_usb_table);
>> +
>> +static inline int kvaser_usb_send_msg(const struct kvaser_usb *dev,
>> +				      struct kvaser_msg *msg)
>> +{
>> +	int actual_len;
>> +
>> +	return usb_bulk_msg(dev->udev,
>> +			    usb_sndbulkpipe(dev->udev,
>> +					dev->bulk_out->bEndpointAddress),
>> +			    msg, msg->len, &actual_len,
>> +			    USB_SEND_TIMEOUT);
>> +}
>> +
>> +static int kvaser_usb_wait_msg(const struct kvaser_usb *dev, u8 id,
>> +			       struct kvaser_msg *msg)
>> +{
>> +	struct kvaser_msg *tmp;
>> +	void *buf;
>> +	int actual_len;
>> +	int err;
>> +	int pos = 0;
>> +
>> +	buf = kzalloc(RX_BUFFER_SIZE, GFP_KERNEL);
>> +	if (!buf)
>> +		return -ENOMEM;
>> +
>> +	err = usb_bulk_msg(dev->udev,
>> +			   usb_rcvbulkpipe(dev->udev,
>> +					   dev->bulk_in->bEndpointAddress),
>> +			   buf, RX_BUFFER_SIZE, &actual_len,
>> +			   USB_RECV_TIMEOUT);
>> +	if (err < 0)
>> +		goto end;
>> +
>> +	while (pos <= actual_len - MSG_HEADER_LEN) {
>> +		tmp = buf + pos;
>> +
>> +		if (!tmp->len)
>> +			break;
>> +
>> +		if (pos + tmp->len > actual_len) {
>> +			dev_err(dev->udev->dev.parent, "Format error\n");
>> +			break;
>> +		}
>> +
>> +		if (tmp->id == id) {
>> +			memcpy(msg, tmp, tmp->len);
>> +			goto end;
>> +		}
>> +
>> +		pos += tmp->len;
>> +	}
>> +
>> +	err = -EINVAL;
>> +
>> +end:
>> +	kfree(buf);
>> +
>> +	return err;
>> +}
>> +
>> +static int kvaser_usb_send_simple_msg(const struct kvaser_usb *dev,
>> +				      u8 msg_id, int channel)
>> +{
>> +	struct kvaser_msg msg = {
>> +		.len = MSG_HEADER_LEN + sizeof(struct kvaser_msg_simple),
>> +		.id = msg_id,
>> +		.u.simple.channel = channel,
>> +		.u.simple.tid = 0xff,
>> +	};
>> +
>> +	return kvaser_usb_send_msg(dev, &msg);
>> +}
>> +
>> +static int kvaser_usb_get_software_info(struct kvaser_usb *dev)
>> +{
>> +	struct kvaser_msg msg;
>> +	int err;
>> +
>> +	err = kvaser_usb_send_simple_msg(dev, CMD_GET_SOFTWARE_INFO, 0);
>> +	if (err)
>> +		return err;
>> +
>> +	err = kvaser_usb_wait_msg(dev, CMD_GET_SOFTWARE_INFO_REPLY, &msg);
>> +	if (err)
>> +		return err;
>> +
>> +	dev->fw_version = le32_to_cpu(msg.u.softinfo.fw_version);
>> +
>> +	return 0;
>> +}
>> +
>> +static int kvaser_usb_get_card_info(struct kvaser_usb *dev)
>> +{
>> +	struct kvaser_msg msg;
>> +	int err;
>> +
>> +	err = kvaser_usb_send_simple_msg(dev, CMD_GET_CARD_INFO, 0);
>> +	if (err)
>> +		return err;
>> +
>> +	err = kvaser_usb_wait_msg(dev, CMD_GET_CARD_INFO_REPLY, &msg);
>> +	if (err)
>> +		return err;
>> +
>> +	dev->nchannels = msg.u.cardinfo.nchannels;
>> +
>> +	return 0;
>> +}
>> +
>> +static void kvaser_usb_tx_acknowledge(const struct kvaser_usb *dev,
>> +				      const struct kvaser_msg *msg)
>> +{
>> +	struct net_device_stats *stats;
>> +	struct kvaser_usb_tx_urb_context *context;
>> +	struct kvaser_usb_net_priv *priv;
>> +	struct sk_buff *skb;
>> +	struct can_frame *cf;
>> +	u8 channel = msg->u.tx_acknowledge.channel;
>> +	u8 tid = msg->u.tx_acknowledge.tid;
>> +
>> +	if (channel >= dev->nchannels) {
>> +		dev_err(dev->udev->dev.parent,
>> +			"Invalid channel number (%d)\n", channel);
>> +		return;
>> +	}
>> +
>> +	priv = dev->nets[channel];
>> +
>> +	if (!netif_device_present(priv->netdev))
>> +		return;
>> +
>> +	stats = &priv->netdev->stats;
>> +
>> +	context = &priv->tx_contexts[tid % MAX_TX_URBS];
>> +
>> +	/* Sometimes the state change doesn't come after a bus-off event */
>> +	if (priv->can.restart_ms &&
>> +	    (priv->can.state >= CAN_STATE_BUS_OFF)) {
>> +		skb = alloc_can_err_skb(priv->netdev, &cf);
>> +		if (skb) {
>> +			cf->can_id |= CAN_ERR_RESTARTED;
>> +			netif_rx(skb);
>> +
>> +			stats->rx_packets++;
>> +			stats->rx_bytes += cf->can_dlc;
>> +		} else {
>> +			netdev_err(priv->netdev,
>> +				   "No memory left for err_skb\n");
>> +		}
>> +
>> +		priv->can.can_stats.restarts++;
>> +		netif_carrier_on(priv->netdev);
>> +
>> +		priv->can.state = CAN_STATE_ERROR_ACTIVE;
>> +	}
>> +
>> +	stats->tx_packets++;
>> +	stats->tx_bytes += context->dlc;
>> +	can_get_echo_skb(priv->netdev, context->echo_index);
>> +
>> +	context->echo_index = MAX_TX_URBS;
>> +	atomic_dec(&priv->active_tx_urbs);
>> +
>> +	netif_wake_queue(priv->netdev);
>> +}
>> +
>> +static void kvaser_usb_simple_msg_callback(struct urb *urb)
>> +{
>> +	struct net_device *netdev = urb->context;
>> +
>> +	kfree(urb->transfer_buffer);
>> +
>> +	if (urb->status)
>> +		netdev_warn(netdev, "urb status received: %d\n",
>> +			    urb->status);
>> +}
>> +
>> +static int kvaser_usb_simple_msg_async(struct kvaser_usb_net_priv *priv,
>> +				       u8 msg_id)
>> +{
>> +	struct kvaser_usb *dev = priv->dev;
>> +	struct net_device *netdev = priv->netdev;
>> +	struct kvaser_msg *msg;
>> +	struct urb *urb;
>> +	void *buf;
>> +	int err;
>> +
>> +	urb = usb_alloc_urb(0, GFP_ATOMIC);
>> +	if (!urb) {
>> +		netdev_err(netdev, "No memory left for URBs\n");
>> +		return -ENOMEM;
>> +	}
>> +
>> +	buf = kmalloc(sizeof(struct kvaser_msg), GFP_ATOMIC);
>> +	if (!buf) {
> 
> Do you have to free the usb you just allocated?
> 
>> +		netdev_err(netdev, "No memory left for USB buffer\n");
>> +		return -ENOMEM;
>> +	}
>> +
>> +	msg = (struct kvaser_msg *)buf;
>> +	msg->len = MSG_HEADER_LEN + sizeof(struct kvaser_msg_simple);
>> +	msg->id = msg_id;
>> +	msg->u.simple.channel = priv->channel;
>> +
>> +	usb_fill_bulk_urb(urb, dev->udev,
>> +			  usb_sndbulkpipe(dev->udev,
>> +					  dev->bulk_out->bEndpointAddress),
>> +			  buf, msg->len,
>> +			  kvaser_usb_simple_msg_callback, priv);
>> +	usb_anchor_urb(urb, &priv->tx_submitted);
>> +
>> +	err = usb_submit_urb(urb, GFP_ATOMIC);
>> +	if (err) {
>> +		netdev_err(netdev, "Error transmitting URB\n");
>> +		usb_unanchor_urb(urb);
>> +		kfree(buf);
>> +		return err;
> 
> and here?
> 
>> +	}
>> +
>> +	usb_free_urb(urb);
>> +
>> +	return 0;
>> +}
>> +
>> +static void kvaser_usb_unlink_tx_urbs(struct kvaser_usb_net_priv *priv)
>> +{
>> +	int i;
>> +
>> +	usb_kill_anchored_urbs(&priv->tx_submitted);
>> +	atomic_set(&priv->active_tx_urbs, 0);
>> +
>> +	for (i = 0; i < MAX_TX_URBS; i++)
>> +		priv->tx_contexts[i].echo_index = MAX_TX_URBS;
>> +}
>> +
>> +static void kvaser_usb_rx_error(const struct kvaser_usb *dev,
>> +				const struct kvaser_msg *msg)
>> +{
>> +	struct can_frame *cf;
>> +	struct sk_buff *skb;
>> +	struct net_device_stats *stats;
>> +	struct kvaser_usb_net_priv *priv;
>> +	unsigned int new_state;
>> +	u8 channel, status, txerr, rxerr, error_factor;
>> +
>> +	switch (msg->id) {
>> +	case CMD_CAN_ERROR_EVENT:
>> +		channel = msg->u.error_event.channel;
>> +		status =  msg->u.error_event.status;
>> +		txerr = msg->u.error_event.tx_errors_count;
>> +		rxerr = msg->u.error_event.rx_errors_count;
>> +		error_factor = msg->u.error_event.error_factor;
>> +		break;
>> +	case CMD_LOG_MESSAGE:
>> +		channel = msg->u.log_message.channel;
>> +		status = msg->u.log_message.data[0];
>> +		txerr = msg->u.log_message.data[2];
>> +		rxerr = msg->u.log_message.data[3];
>> +		error_factor = msg->u.log_message.data[1];
>> +		break;
>> +	case CMD_CHIP_STATE_EVENT:
>> +		channel = msg->u.chip_state_event.channel;
>> +		status =  msg->u.chip_state_event.status;
>> +		txerr = msg->u.chip_state_event.tx_errors_count;
>> +		rxerr = msg->u.chip_state_event.rx_errors_count;
>> +		error_factor = 0;
>> +		break;
>> +	default:
>> +		dev_err(dev->udev->dev.parent, "Invalid msg id (%d)\n",
>> +			msg->id);
>> +		return;
>> +	}
>> +
>> +	if (channel >= dev->nchannels) {
>> +		dev_err(dev->udev->dev.parent,
>> +			"Invalid channel number (%d)\n", channel);
>> +		return;
>> +	}
>> +
>> +	priv = dev->nets[channel];
>> +	stats = &priv->netdev->stats;
>> +
>> +	if (status & M16C_STATE_BUS_RESET) {
>> +		kvaser_usb_unlink_tx_urbs(priv);
>> +		return;
>> +	}
>> +
>> +	skb = alloc_can_err_skb(priv->netdev, &cf);
>> +	if (!skb) {
>> +		stats->rx_dropped++;
>> +		return;
>> +	}
>> +
>> +	cf->can_id |= CAN_ERR_BUSERROR;

At state change is *not* a bus error. The line above should e moved into
the "if (error_factor)" block below.

>> +
>> +	new_state = priv->can.state;
>> +
>> +	netdev_dbg(priv->netdev, "Error status: 0x%02x\n", status);
>> +
>> +	if (status & M16C_STATE_BUS_OFF) {
>> +		cf->can_id |= CAN_ERR_BUSOFF;
>> +
>> +		priv->can.can_stats.bus_off++;
>> +		if (!priv->can.restart_ms)
>> +			kvaser_usb_simple_msg_async(priv, CMD_STOP_CHIP);
>> +
>> +		netif_carrier_off(priv->netdev);
>> +
>> +		new_state = CAN_STATE_BUS_OFF;
>> +	}
>> +
>> +	if (status & M16C_STATE_BUS_PASSIVE) {
> 
> else if ()
> 
> as bus passive and bus off is mutually exclusive.
> 
>> +		if (priv->can.state != CAN_STATE_ERROR_PASSIVE) {
>> +			cf->can_id |= CAN_ERR_CRTL;
>> +
>> +			if ((txerr > 0) || (rxerr > 0))

if (txerr | rxerr) ?

>> +				cf->data[1] = (txerr > rxerr)
>> +						? CAN_ERR_CRTL_TX_PASSIVE
>> +						: CAN_ERR_CRTL_RX_PASSIVE;
>> +			else
>> +				cf->data[1] = CAN_ERR_CRTL_TX_PASSIVE |
>> +					      CAN_ERR_CRTL_RX_PASSIVE;
>> +
>> +			priv->can.can_stats.error_passive++;
>> +		}
>> +
>> +		new_state = CAN_STATE_ERROR_PASSIVE;
>> +	}
>> +
>> +	if (status == M16C_STATE_BUS_ERROR) {
>> +		if ((priv->can.state < CAN_STATE_ERROR_WARNING) &&
>> +		    ((txerr > 96) || (rxerr > 96))) {
> 
> Is is >= 96 ?

Yep.

>> +			cf->can_id |= CAN_ERR_CRTL;
>> +			cf->data[1] = (txerr > rxerr)
>> +					? CAN_ERR_CRTL_TX_WARNING
>> +					: CAN_ERR_CRTL_RX_WARNING;
>> +
>> +			priv->can.can_stats.error_warning++;
>> +			new_state = CAN_STATE_ERROR_WARNING;
>> +		} else if (priv->can.state > CAN_STATE_ERROR_ACTIVE) {
>> +			cf->can_id |= CAN_ERR_PROT;
>> +			cf->data[2] = CAN_ERR_PROT_ACTIVE;
>> +
>> +			new_state = CAN_STATE_ERROR_ACTIVE;
>> +		}
>> +	}
>> +
>> +	if (!status) {
>> +		cf->can_id |= CAN_ERR_PROT;
>> +		cf->data[2] = CAN_ERR_PROT_ACTIVE;
>> +
>> +		new_state = CAN_STATE_ERROR_ACTIVE;
>> +	}
>> +
>> +	if (priv->can.restart_ms &&
>> +	    (priv->can.state >= CAN_STATE_BUS_OFF) &&
>> +	    (new_state < CAN_STATE_BUS_OFF)) {
>> +		cf->can_id |= CAN_ERR_RESTARTED;
>> +		netif_carrier_on(priv->netdev);
>> +
>> +		priv->can.can_stats.restarts++;
>> +	}
>> +
>> +	if (error_factor) {
>> +		priv->can.can_stats.bus_error++;
>> +		stats->rx_errors++;
>> +
>> +		cf->can_id |= CAN_ERR_PROT;
>> +
>> +		if (error_factor & M16C_EF_ACKE)
>> +			cf->data[3] |= (CAN_ERR_PROT_LOC_ACK);
>> +		if (error_factor & M16C_EF_CRCE)
>> +			cf->data[3] |= (CAN_ERR_PROT_LOC_CRC_SEQ |
>> +					CAN_ERR_PROT_LOC_CRC_DEL);
>> +		if (error_factor & M16C_EF_FORME)
>> +			cf->data[2] |= CAN_ERR_PROT_FORM;
>> +		if (error_factor & M16C_EF_STFE)
>> +			cf->data[2] |= CAN_ERR_PROT_STUFF;
>> +		if (error_factor & M16C_EF_BITE0)
>> +			cf->data[2] |= CAN_ERR_PROT_BIT0;
>> +		if (error_factor & M16C_EF_BITE1)
>> +			cf->data[2] |= CAN_ERR_PROT_BIT1;
>> +		if (error_factor & M16C_EF_TRE)
>> +			cf->data[2] |= CAN_ERR_PROT_TX;
>> +	}
>> +
>> +	cf->data[6] = txerr;
>> +	cf->data[7] = rxerr;
>> +
>> +	priv->bec.txerr = txerr;
>> +	priv->bec.rxerr = rxerr;
>> +
>> +	priv->can.state = new_state;
>> +
>> +	netif_rx(skb);
>> +
>> +	stats->rx_packets++;
>> +	stats->rx_bytes += cf->can_dlc;
>> +}
>> +
>> +static void kvaser_usb_rx_can_msg(const struct kvaser_usb *dev,
>> +				  const struct kvaser_msg *msg)
>> +{
>> +	struct kvaser_usb_net_priv *priv;
>> +	struct can_frame *cf;
>> +	struct sk_buff *skb;
>> +	struct net_device_stats *stats;
>> +	u8 channel = msg->u.rx_can.channel;
>> +
>> +	if (channel >= dev->nchannels) {
>> +		dev_err(dev->udev->dev.parent,
>> +			"Invalid channel number (%d)\n", channel);
>> +		return;
>> +	}
>> +
>> +	priv = dev->nets[channel];
>> +	stats = &priv->netdev->stats;
>> +
>> +	skb = alloc_can_skb(priv->netdev, &cf);
>> +	if (!skb) {
>> +		stats->tx_dropped++;
>> +		return;
>> +	}
>> +
>> +	cf->can_id = ((msg->u.rx_can.msg[0] & 0x1f) << 6) |
>> +		     (msg->u.rx_can.msg[1] & 0x3f);
>> +	cf->can_dlc = get_can_dlc(msg->u.rx_can.msg[5]);
>> +
>> +	if (msg->id == CMD_RX_EXT_MESSAGE) {
>> +		cf->can_id <<= 18;
>> +		cf->can_id |= ((msg->u.rx_can.msg[2] & 0x0f) << 14) |
>> +			      ((msg->u.rx_can.msg[3] & 0xff) << 6) |
>> +			      (msg->u.rx_can.msg[4] & 0x3f);
>> +		cf->can_id |= CAN_EFF_FLAG;
>> +	}
>> +
>> +	if (msg->u.rx_can.flag & MSG_FLAG_REMOTE_FRAME) {
>> +		cf->can_id |= CAN_RTR_FLAG;
>> +	} else if (msg->u.rx_can.flag & (MSG_FLAG_ERROR_FRAME |
>> +					 MSG_FLAG_NERR)) {
>> +		cf->can_id |= CAN_ERR_FLAG;
>> +		cf->can_dlc = CAN_ERR_DLC;

> Please move the error skb creation handling into a subfunction, use
> can_alloc_err_skb() in that function. Please move the:
> 
>     if (msg->u.rx_can.flag & ...)
> 
> up in this function, before the alloc_can_skb().
> 
>> +
>> +		netdev_err(priv->netdev, "Unknow error (flags: 0x%02x)\n",
>> +			   msg->u.rx_can.flag);
>> +
>> +		stats->rx_errors++;

This an *error* which does normally not happen, IIRC. Therefore I do not
see a need to pass it to the user as error message.

>> +	} else if (msg->u.rx_can.flag & MSG_FLAG_OVERRUN) {
>> +		cf->can_id = CAN_ERR_FLAG | CAN_ERR_CRTL;
>> +		cf->can_dlc = CAN_ERR_DLC;
>> +		cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
>> +
>> +		stats->rx_over_errors++;
>> +		stats->rx_errors++;
> 
> This should go into the error skb generation function, too.
> 
>> +	} else if (!msg->u.rx_can.flag) {
>> +		memcpy(cf->data, &msg->u.rx_can.msg[6], cf->can_dlc);
> 
> Please don't copy the contents of RTR frames.
> 
>> +	} else {
>> +		kfree_skb(skb);
> 
> After you have moved the error skb generation into a seperate function,
> you should get rid of the kfree(skb), too. The function should look like
> this (pseude code):
> 
> static void kvaser_usb_rx_can_msg(const struct kvaser_usb *dev,
> 				  const struct kvaser_msg *msg)
> {
> 	if (channel_invalid())
> 		return;
> 
> 	if (msg->u.rx_can.flag & ERROR) {
> 		kvaser_usb_rx_can_err_msg();
> 		return;
> 	} else if (msg->u.rx_can.flag & INVALID_FRAME) {
> 		return;
> 	}
> 
> 	skb = alloc_can_skb();
> 
> 	/* existing dlc, rtr and data handling code */
> 	...
> }
> 
> 
>> +		return;
>> +	}
>> +
>> +	netif_rx(skb);
>> +
>> +	stats->rx_packets++;
>> +	stats->rx_bytes += cf->can_dlc;
>> +}
>> +
>> +static void kvaser_usb_start_chip_reply(const struct kvaser_usb *dev,
>> +					const struct kvaser_msg *msg)
>> +{
>> +	struct kvaser_usb_net_priv *priv;
>> +	u8 channel = msg->u.simple.channel;
>> +
>> +	if (channel >= dev->nchannels) {
>> +		dev_err(dev->udev->dev.parent,
>> +			"Invalid channel number (%d)\n", channel);
>> +		return;
>> +	}
>> +
>> +	priv = dev->nets[channel];
>> +
>> +	if (completion_done(&priv->start_comp) &&
>> +	    netif_queue_stopped(priv->netdev)) {
>> +		netif_wake_queue(priv->netdev);
>> +	} else {
>> +		netif_start_queue(priv->netdev);
>> +		complete(&priv->start_comp);
>> +	}
>> +}
>> +
>> +static void kvaser_usb_stop_chip_reply(const struct kvaser_usb *dev,
>> +				       const struct kvaser_msg *msg)
>> +{
>> +	struct kvaser_usb_net_priv *priv;
>> +	u8 channel = msg->u.simple.channel;
>> +
>> +	if (channel >= dev->nchannels) {
>> +		dev_err(dev->udev->dev.parent,
>> +			"Invalid channel number (%d)\n", channel);
>> +		return;
>> +	}
>> +
>> +	priv = dev->nets[channel];
>> +
>> +	complete(&priv->stop_comp);
>> +}
>> +
>> +static void kvaser_usb_handle_message(const struct kvaser_usb *dev,
>> +				      const struct kvaser_msg *msg)
>> +{
>> +	switch (msg->id) {
>> +	case CMD_START_CHIP_REPLY:
>> +		kvaser_usb_start_chip_reply(dev, msg);
>> +		break;
>> +
>> +	case CMD_STOP_CHIP_REPLY:
>> +		kvaser_usb_stop_chip_reply(dev, msg);
>> +		break;
>> +
>> +	case CMD_RX_STD_MESSAGE:
>> +	case CMD_RX_EXT_MESSAGE:
>> +		kvaser_usb_rx_can_msg(dev, msg);
>> +		break;
>> +
>> +	case CMD_CHIP_STATE_EVENT:
>> +	case CMD_CAN_ERROR_EVENT:
>> +		kvaser_usb_rx_error(dev, msg);
>> +		break;
>> +
>> +	case CMD_LOG_MESSAGE:
>> +		if (msg->u.log_message.flags & MSG_FLAG_ERROR_FRAME)
>> +			kvaser_usb_rx_error(dev, msg);
>> +		break;
>> +
>> +	case CMD_TX_ACKNOWLEDGE:
>> +		kvaser_usb_tx_acknowledge(dev, msg);
>> +		break;
>> +
>> +	default:
>> +		dev_warn(dev->udev->dev.parent,
>> +			 "Unhandled message (%d)\n", msg->id);
>> +		break;
>> +	}
>> +}
>> +
>> +static void kvaser_usb_read_bulk_callback(struct urb *urb)
>> +{
>> +	struct kvaser_usb *dev = urb->context;
>> +	struct kvaser_msg *msg;
>> +	int pos = 0;
>> +	int err, i;
>> +
>> +	switch (urb->status) {
>> +	case 0:
>> +		break;
>> +	case -ENOENT:
>> +	case -ESHUTDOWN:
>> +		return;
>> +	default:
>> +		dev_info(dev->udev->dev.parent, "Rx URB aborted (%d)\n",
>> +			 urb->status);
>> +		goto resubmit_urb;
>> +	}
>> +
>> +	while (pos <= urb->actual_length - MSG_HEADER_LEN) {
>> +		msg = urb->transfer_buffer + pos;
>> +
>> +		if (!msg->len)
>> +			break;
>> +
>> +		if (pos + msg->len > urb->actual_length) {
>> +			dev_err(dev->udev->dev.parent, "Format error\n");
>> +			break;
>> +		}
>> +
>> +		kvaser_usb_handle_message(dev, msg);
>> +
>> +		pos += msg->len;
>> +	}
>> +
>> +resubmit_urb:
>> +	usb_fill_bulk_urb(urb, dev->udev,
>> +			  usb_rcvbulkpipe(dev->udev,
>> +					  dev->bulk_in->bEndpointAddress),
>> +			  urb->transfer_buffer, RX_BUFFER_SIZE,
>> +			  kvaser_usb_read_bulk_callback, dev);
>> +
>> +	err = usb_submit_urb(urb, GFP_ATOMIC);
>> +	if (err == -ENODEV) {
>> +		for (i = 0; i < dev->nchannels; i++) {
>> +			if (!dev->nets[i])
>> +				continue;
>> +
>> +			netif_device_detach(dev->nets[i]->netdev);
>> +		}
>> +	} else if (err) {
>> +		dev_err(dev->udev->dev.parent,
>> +			"Failed resubmitting read bulk urb: %d\n", err);
>> +	}
>> +
>> +	return;
>> +}
>> +
>> +static int kvaser_usb_setup_rx_urbs(struct kvaser_usb *dev)
>> +{
>> +	int i, err = 0;
>> +
>> +	if (dev->rxinitdone)
>> +		return 0;
>> +
>> +	for (i = 0; i < MAX_RX_URBS; i++) {
>> +		struct urb *urb = NULL;
>> +		u8 *buf = NULL;
>> +		dma_addr_t buf_dma;
>> +
>> +		urb = usb_alloc_urb(0, GFP_KERNEL);
>> +		if (!urb) {
>> +			dev_warn(dev->udev->dev.parent,
>> +				 "No memory left for URBs\n");
>> +			err = -ENOMEM;
>> +			break;
>> +		}
>> +
>> +		buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE,
>> +					 GFP_KERNEL, &buf_dma);
>> +		if (!buf) {
>> +			dev_warn(dev->udev->dev.parent,
>> +				 "No memory left for USB buffer\n");
>> +			usb_free_urb(urb);
>> +			err = -ENOMEM;
>> +			break;
>> +		}
>> +
>> +		usb_fill_bulk_urb(urb, dev->udev,
>> +				  usb_rcvbulkpipe(dev->udev,
>> +					  dev->bulk_in->bEndpointAddress),
>> +				  buf, RX_BUFFER_SIZE,
>> +				  kvaser_usb_read_bulk_callback,
>> +				  dev);
>> +		urb->transfer_dma = buf_dma;
>> +		urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
>> +		usb_anchor_urb(urb, &dev->rx_submitted);
>> +
>> +		err = usb_submit_urb(urb, GFP_KERNEL);
>> +		if (err) {
>> +			usb_unanchor_urb(urb);
>> +			usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf,
>> +					  buf_dma);
> 
> Do you have to call usb_free_usb() here, or does the usb frame work take
> care of this?
> 
>> +			break;
>> +		}
>> +
>> +		dev->rxbuf[i] = buf;
>> +		dev->rxbuf_dma[i] = buf_dma;
>> +
>> +		usb_free_urb(urb);
>> +	}
>> +
>> +	if (i == 0) {
>> +		dev_warn(dev->udev->dev.parent,
>> +			 "Cannot setup read URBs, error %d\n", err);
>> +		return err;
>> +	} else if (i < MAX_RX_URBS) {
>> +		dev_warn(dev->udev->dev.parent,
>> +			 "RX performances may be slow\n");
>> +	}
>> +
>> +	dev->rxinitdone = true;
>> +
>> +	return 0;
>> +}
>> +
>> +static int kvaser_usb_set_opt_mode(const struct kvaser_usb_net_priv *priv)
>> +{
>> +	struct kvaser_msg msg = {
>> +		.id = CMD_SET_CTRL_MODE,
>> +		.len = MSG_HEADER_LEN +
>> +		       sizeof(struct kvaser_msg_ctrl_mode),
>> +		.u.ctrl_mode.tid = 0xff,
>> +		.u.ctrl_mode.channel = priv->channel,
>> +	};
>> +
>> +	if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
>> +		msg.u.ctrl_mode.ctrl_mode = KVASER_CTRL_MODE_SILENT;
>> +	else
>> +		msg.u.ctrl_mode.ctrl_mode = KVASER_CTRL_MODE_NORMAL;
>> +
>> +	return kvaser_usb_send_msg(priv->dev, &msg);
>> +}
>> +
>> +static int kvaser_usb_start_chip(struct kvaser_usb_net_priv *priv)
>> +{
>> +	int err;
>> +
>> +	init_completion(&priv->start_comp);
>> +
>> +	err = kvaser_usb_send_simple_msg(priv->dev, CMD_START_CHIP,
>> +					 priv->channel);
>> +	if (err)
>> +		return err;
>> +
>> +	if (!wait_for_completion_timeout(&priv->start_comp,
>> +					 msecs_to_jiffies(START_TIMEOUT)))
>> +		return -ETIMEDOUT;
>> +
>> +	return 0;
>> +}
>> +
>> +static int kvaser_usb_open(struct net_device *netdev)
>> +{
>> +	struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
>> +	struct kvaser_usb *dev = priv->dev;
>> +	int err;
>> +
>> +	err = open_candev(netdev);
>> +	if (err)
>> +		return err;
>> +
>> +	err = kvaser_usb_setup_rx_urbs(dev);
>> +	if (err)
>> +		goto error;
>> +
>> +	err = kvaser_usb_set_opt_mode(priv);
>> +	if (err)
>> +		goto error;
>> +
>> +	err = kvaser_usb_start_chip(priv);
>> +	if (err) {
>> +		netdev_warn(netdev, "Cannot start device, error %d\n", err);
>> +		goto error;
>> +	}
>> +
>> +	priv->can.state = CAN_STATE_ERROR_ACTIVE;
>> +
>> +	return 0;
>> +
>> +error:
>> +	close_candev(netdev);
>> +	return err;
>> +}
>> +
>> +static void kvaser_usb_unlink_all_urbs(struct kvaser_usb *dev)
>> +{
>> +	int i;
>> +
>> +	usb_kill_anchored_urbs(&dev->rx_submitted);
>> +
>> +	for (i = 0; i < MAX_RX_URBS; i++)
>> +		usb_free_coherent(dev->udev, RX_BUFFER_SIZE,
>> +				  dev->rxbuf[i],
>> +				  dev->rxbuf_dma[i]);
>> +
>> +	for (i = 0; i < MAX_NET_DEVICES; i++) {
>> +		struct kvaser_usb_net_priv *priv = dev->nets[i];
>> +
>> +		if (priv)
>> +			kvaser_usb_unlink_tx_urbs(priv);
>> +	}
>> +}
>> +
>> +static int kvaser_usb_stop_chip(struct kvaser_usb_net_priv *priv)
>> +{
>> +	int err;
>> +
>> +	init_completion(&priv->stop_comp);
>> +
>> +	err = kvaser_usb_send_simple_msg(priv->dev, CMD_STOP_CHIP,
>> +					 priv->channel);
>> +	if (err)
>> +		return err;
>> +
>> +	if (!wait_for_completion_timeout(&priv->stop_comp,
>> +					 msecs_to_jiffies(STOP_TIMEOUT)))
>> +		return -ETIMEDOUT;
>> +
>> +	return 0;
>> +}
>> +
>> +static int kvaser_usb_flush_queue(struct kvaser_usb_net_priv *priv)
>> +{
>> +	struct kvaser_msg msg = {
>> +		.id = CMD_FLUSH_QUEUE,
>> +		.len = MSG_HEADER_LEN +
>> +		       sizeof(struct kvaser_msg_flush_queue),
>> +		.u.flush_queue.channel = priv->channel,
>> +		.u.flush_queue.flags = 0x00,
>> +	};
>> +
>> +	return kvaser_usb_send_msg(priv->dev, &msg);
>> +}
>> +
>> +static int kvaser_usb_close(struct net_device *netdev)
>> +{
>> +	struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
>> +	struct kvaser_usb *dev = priv->dev;
>> +	int err;
>> +
>> +	netif_stop_queue(netdev);
>> +
>> +	err = kvaser_usb_flush_queue(priv);
>> +	if (err)
>> +		netdev_warn(netdev, "Cannot flush queue, error %d\n", err);
>> +
>> +	if (kvaser_usb_send_simple_msg(dev, CMD_RESET_CHIP, priv->channel))
>> +		netdev_warn(netdev, "Cannot reset card, error %d\n", err);
>> +
>> +	err = kvaser_usb_stop_chip(priv);
>> +	if (err)
>> +		netdev_warn(netdev, "Cannot stop device, error %d\n", err);
>> +
>> +	priv->can.state = CAN_STATE_STOPPED;
>> +	close_candev(priv->netdev);
>> +
>> +	return 0;
>> +}
>> +
>> +static void kvaser_usb_write_bulk_callback(struct urb *urb)
>> +{
>> +	struct kvaser_usb_tx_urb_context *context = urb->context;
>> +	struct kvaser_usb_net_priv *priv;
>> +	struct net_device *netdev;
>> +
>> +	if (WARN_ON(!context))
>> +		return;
>> +
>> +	priv = context->priv;
>> +	netdev = priv->netdev;
>> +
>> +	kfree(urb->transfer_buffer);
>> +
>> +	if (!netif_device_present(netdev))
>> +		return;
>> +
>> +	if (urb->status)
>> +		netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status);
>> +}
>> +
>> +static netdev_tx_t kvaser_usb_start_xmit(struct sk_buff *skb,
>> +					 struct net_device *netdev)
>> +{
>> +	struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
>> +	struct kvaser_usb *dev = priv->dev;
>> +	struct net_device_stats *stats = &netdev->stats;
>> +	struct can_frame *cf = (struct can_frame *)skb->data;
>> +	struct kvaser_usb_tx_urb_context *context = NULL;
>> +	struct urb *urb;
>> +	void *buf;
>> +	struct kvaser_msg *msg;
>> +	int i, err;
>> +	int ret = NETDEV_TX_OK;
>> +
>> +	if (can_dropped_invalid_skb(netdev, skb))
>> +		return NETDEV_TX_OK;
>> +
>> +	urb = usb_alloc_urb(0, GFP_ATOMIC);
>> +	if (!urb) {
>> +		netdev_err(netdev, "No memory left for URBs\n");
>> +		stats->tx_dropped++;
>> +		dev_kfree_skb(skb);
>> +		return NETDEV_TX_OK;
>> +	}
>> +
>> +	buf = kmalloc(sizeof(struct kvaser_msg), GFP_ATOMIC);
>> +	if (!buf) {
>> +		netdev_err(netdev, "No memory left for USB buffer\n");
>> +		stats->tx_dropped++;
>> +		dev_kfree_skb(skb);
> What about the urb?
>> +		goto nobufmem;
>> +	}
>> +
>> +	msg = (struct kvaser_msg *)buf;
> 
> nitpick: cast is not needed, as buf is void *
> 
>> +	msg->len = MSG_HEADER_LEN + sizeof(struct kvaser_msg_tx_can);
>> +	msg->u.tx_can.flags = 0;
>> +	msg->u.tx_can.channel = priv->channel;
>> +
>> +	if (cf->can_id & CAN_EFF_FLAG) {
>> +		msg->id = CMD_TX_EXT_MESSAGE;
>> +		msg->u.tx_can.msg[0] = (cf->can_id >> 24) & 0x1f;
>> +		msg->u.tx_can.msg[1] = (cf->can_id >> 18) & 0x3f;
>> +		msg->u.tx_can.msg[2] = (cf->can_id >> 14) & 0x0f;
>> +		msg->u.tx_can.msg[3] = (cf->can_id >> 6) & 0xff;
>> +		msg->u.tx_can.msg[4] = cf->can_id & 0x3f;
>> +	} else {
>> +		msg->id = CMD_TX_STD_MESSAGE;
>> +		msg->u.tx_can.msg[0] = (cf->can_id >> 6) & 0x1f;
>> +		msg->u.tx_can.msg[1] = cf->can_id & 0x3f;
>> +	}
>> +
>> +	msg->u.tx_can.msg[5] = cf->can_dlc;
>> +	memcpy(&msg->u.tx_can.msg[6], cf->data, cf->can_dlc);
>> +
>> +	if (cf->can_id & CAN_RTR_FLAG)
>> +		msg->u.tx_can.flags |= MSG_FLAG_REMOTE_FRAME;
>> +
>> +	for (i = 0; i < ARRAY_SIZE(priv->tx_contexts); i++) {
>> +		if (priv->tx_contexts[i].echo_index == MAX_TX_URBS) {
>> +			context = &priv->tx_contexts[i];
>> +			break;
>> +		}
>> +	}
>> +
>> +	if (!context) {
>> +		netdev_warn(netdev, "cannot find free context\n");
>> +		ret =  NETDEV_TX_BUSY;
>> +		goto releasebuf;
>> +	}
>> +
>> +	context->priv = priv;
>> +	context->echo_index = i;
>> +	context->dlc = cf->can_dlc;
>> +
>> +	msg->u.tx_can.tid = context->echo_index;
>> +
>> +	usb_fill_bulk_urb(urb, dev->udev,
>> +			  usb_sndbulkpipe(dev->udev,
>> +					  dev->bulk_out->bEndpointAddress),
>> +			  buf, msg->len,
>> +			  kvaser_usb_write_bulk_callback, context);
>> +	usb_anchor_urb(urb, &priv->tx_submitted);
>> +
>> +	can_put_echo_skb(skb, netdev, context->echo_index);
>> +
>> +	atomic_inc(&priv->active_tx_urbs);
>> +
>> +	if (atomic_read(&priv->active_tx_urbs) >= MAX_TX_URBS)
>> +		netif_stop_queue(netdev);
>> +
>> +	err = usb_submit_urb(urb, GFP_ATOMIC);
>> +	if (unlikely(err)) {
>> +		can_free_echo_skb(netdev, context->echo_index);
>> +
>> +		atomic_dec(&priv->active_tx_urbs);
>> +		usb_unanchor_urb(urb);
>> +
>> +		stats->tx_dropped++;
>> +
>> +		if (err == -ENODEV)
>> +			netif_device_detach(netdev);
>> +		else
>> +			netdev_warn(netdev, "Failed tx_urb %d\n", err);
>> +
>> +		goto releasebuf;
>> +	}
>> +
>> +	netdev->trans_start = jiffies;
> 
> Is this still needed?
> 
>> +
>> +	usb_free_urb(urb);
>> +
>> +	return NETDEV_TX_OK;
>> +
>> +releasebuf:
>> +	kfree(buf);
>> +nobufmem:
>> +	usb_free_urb(urb);
>> +	return ret;
>> +}
>> +
>> +static const struct net_device_ops kvaser_usb_netdev_ops = {
>> +	.ndo_open = kvaser_usb_open,
>> +	.ndo_stop = kvaser_usb_close,
>> +	.ndo_start_xmit = kvaser_usb_start_xmit,
>> +};
>> +
>> +static struct can_bittiming_const kvaser_usb_bittiming_const = {
>> +	.name = "kvaser_usb",
>> +	.tseg1_min = KVASER_USB_TSEG1_MIN,
>> +	.tseg1_max = KVASER_USB_TSEG1_MAX,
>> +	.tseg2_min = KVASER_USB_TSEG2_MIN,
>> +	.tseg2_max = KVASER_USB_TSEG2_MAX,
>> +	.sjw_max = KVASER_USB_SJW_MAX,
>> +	.brp_min = KVASER_USB_BRP_MIN,
>> +	.brp_max = KVASER_USB_BRP_MAX,
>> +	.brp_inc = KVASER_USB_BRP_INC,
>> +};
>> +
>> +static int kvaser_usb_set_bittiming(struct net_device *netdev)
>> +{
>> +	struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
>> +	struct can_bittiming *bt = &priv->can.bittiming;
>> +	struct kvaser_usb *dev = priv->dev;
>> +	struct kvaser_msg msg = {
>> +		.id = CMD_SET_BUS_PARAMS,
>> +		.len = MSG_HEADER_LEN +
>> +		       sizeof(struct kvaser_msg_busparams),
>> +		.u.busparams.channel = priv->channel,
>> +		.u.busparams.tid = 0xff,
>> +		.u.busparams.bitrate = cpu_to_le32(bt->bitrate),
>> +		.u.busparams.sjw = bt->sjw,
>> +		.u.busparams.tseg1 = bt->prop_seg + bt->phase_seg1,
>> +		.u.busparams.tseg2 = bt->phase_seg2,
>> +	};
>> +
>> +	if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
>> +		msg.u.busparams.no_samp = 3;
>> +	else
>> +		msg.u.busparams.no_samp = 1;
>> +
>> +	return kvaser_usb_send_msg(dev, &msg);
>> +}
>> +
>> +static int kvaser_usb_set_mode(struct net_device *netdev,
>> +			       enum can_mode mode)
>> +{
>> +	struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
>> +	int err;
>> +
>> +	switch (mode) {
>> +	case CAN_MODE_START:
>> +		err = kvaser_usb_simple_msg_async(priv, CMD_START_CHIP);
>> +		if (err)
>> +			return err;
>> +		break;
>> +	default:
>> +		return -EOPNOTSUPP;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int kvaser_usb_get_berr_counter(const struct net_device *netdev,
>> +				       struct can_berr_counter *bec)
>> +{
>> +	struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
>> +
>> +	*bec = priv->bec;
>> +
>> +	return 0;
>> +}
>> +
>> +static int kvaser_usb_init_one(struct usb_interface *intf,
>> +			       const struct usb_device_id *id, int channel)
>> +{
>> +	struct kvaser_usb *dev = usb_get_intfdata(intf);
>> +	struct net_device *netdev;
>> +	struct kvaser_usb_net_priv *priv;
>> +	int i, err;
>> +
>> +	netdev = alloc_candev(sizeof(*priv), MAX_TX_URBS);
>> +	if (!netdev) {
>> +		dev_err(&intf->dev, "Cannot alloc candev\n");
>> +		return -ENOMEM;
>> +	}
>> +
>> +	priv = netdev_priv(netdev);
>> +
>> +	init_completion(&priv->start_comp);
>> +	init_completion(&priv->stop_comp);
>> +
>> +	init_usb_anchor(&priv->tx_submitted);
>> +	atomic_set(&priv->active_tx_urbs, 0);
>> +
>> +	for (i = 0; i < ARRAY_SIZE(priv->tx_contexts); i++)
>> +		priv->tx_contexts[i].echo_index = MAX_TX_URBS;
>> +
>> +	priv->dev = dev;
>> +	priv->netdev = netdev;
>> +	priv->channel = channel;
>> +
>> +	priv->can.state = CAN_STATE_STOPPED;
>> +	priv->can.clock.freq = CAN_USB_CLOCK;
>> +	priv->can.bittiming_const = &kvaser_usb_bittiming_const;
>> +	priv->can.do_set_bittiming = kvaser_usb_set_bittiming;
>> +	priv->can.do_set_mode = kvaser_usb_set_mode;
>> +	if (id->driver_info & KVASER_HAS_TXRX_ERRORS)
>> +		priv->can.do_get_berr_counter = kvaser_usb_get_berr_counter;
>> +	priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
>> +	if (id->driver_info & KVASER_HAS_SILENT_MODE)
>> +		priv->can.ctrlmode_supported |= CAN_CTRLMODE_LISTENONLY;
>> +
>> +	netdev->flags |= IFF_ECHO;
>> +
>> +	netdev->netdev_ops = &kvaser_usb_netdev_ops;
>> +
>> +	SET_NETDEV_DEV(netdev, &intf->dev);
>> +
>> +	dev->nets[channel] = priv;
>> +
>> +	err = register_candev(netdev);
>> +	if (err) {
>> +		dev_err(&intf->dev, "Failed to register can device\n");
>> +		free_candev(netdev);
>> +		return err;
>> +	}
>> +
>> +	netdev_dbg(netdev, "device registered\n");
>> +
>> +	return 0;
>> +}
>> +
>> +static void kvaser_usb_get_endpoints(const struct usb_interface *intf,
>> +				     struct usb_endpoint_descriptor **in,
>> +				     struct usb_endpoint_descriptor **out)
>> +{
>> +	const struct usb_host_interface *iface_desc;
>> +	struct usb_endpoint_descriptor *endpoint;
>> +	int i;
>> +
>> +	iface_desc = &intf->altsetting[0];
>> +
>> +	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
>> +		endpoint = &iface_desc->endpoint[i].desc;
>> +
>> +		if (usb_endpoint_is_bulk_in(endpoint))
>> +			*in = endpoint;
>> +
>> +		if (usb_endpoint_is_bulk_out(endpoint))
>> +			*out = endpoint;
>> +	}
>> +}
>> +
>> +static int kvaser_usb_probe(struct usb_interface *intf,
>> +			    const struct usb_device_id *id)
>> +{
>> +	struct kvaser_usb *dev;
>> +	int err = -ENOMEM;
>> +	int i;
>> +
>> +	dev = devm_kzalloc(&intf->dev, sizeof(*dev), GFP_KERNEL);
>> +	if (!dev)
>> +		return -ENOMEM;
>> +
>> +	kvaser_usb_get_endpoints(intf, &dev->bulk_in, &dev->bulk_out);
>> +	if (!dev->bulk_in || !dev->bulk_out) {
>> +		dev_err(&intf->dev, "Cannot get usb endpoint(s)");
>> +		return err;
>> +	}
>> +
>> +	dev->udev = interface_to_usbdev(intf);
>> +
>> +	init_usb_anchor(&dev->rx_submitted);
>> +
>> +	usb_set_intfdata(intf, dev);
>> +
>> +	for (i = 0; i < MAX_NET_DEVICES; i++)
>> +		kvaser_usb_send_simple_msg(dev, CMD_RESET_CHIP, i);
>> +
>> +	err = kvaser_usb_get_software_info(dev);
>> +	if (err) {
>> +		dev_err(&intf->dev,
>> +			"Cannot get software infos, error %d\n", err);
>> +		return err;
>> +	}
>> +
>> +	err = kvaser_usb_get_card_info(dev);
>> +	if (err) {
>> +		dev_err(&intf->dev,
>> +			"Cannot get card infos, error %d\n", err);
>> +		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++)
>> +		kvaser_usb_init_one(intf, id, i);

Error checking is not needed?

>> +
>> +	return 0;
>> +}
>> +
>> +static void kvaser_usb_disconnect(struct usb_interface *intf)
>> +{
>> +	struct kvaser_usb *dev = usb_get_intfdata(intf);
>> +	int i;
>> +
>> +	usb_set_intfdata(intf, NULL);
>> +
>> +	if (!dev)
>> +		return;
>> +
>> +	for (i = 0; i < dev->nchannels; i++) {
>> +		if (!dev->nets[i])
>> +			continue;
>> +
>> +		unregister_netdev(dev->nets[i]->netdev);
>> +	}
>> +
>> +	kvaser_usb_unlink_all_urbs(dev);
>> +
>> +	for (i = 0; i < dev->nchannels; i++)
>> +		free_candev(dev->nets[i]->netdev);
>> +}
>> +
>> +static struct usb_driver kvaser_usb_driver = {
>> +	.name = "kvaser_usb",
>> +	.probe = kvaser_usb_probe,
>> +	.disconnect = kvaser_usb_disconnect,
>> +	.id_table = kvaser_usb_table
>> +};
>> +
>> +module_usb_driver(kvaser_usb_driver);
>> +
>> +MODULE_AUTHOR("Olivier Sobrie <[email-masked]>");
>> +MODULE_DESCRIPTION("CAN driver for Kvaser CAN/USB devices");
>> +MODULE_LICENSE("GPL v2");

Wolfgang.