Re: [PATCH] can: kvaser_usb: Add support for the Usbcan-II family

Ahmed S. Darwish
2014-12-24T15:04:31Z

Hi Olivier,

On Wed, Dec 24, 2014 at 01:36:27PM +0100, Olivier Sobrie wrote:
> Hello Ahmed,
>
> On Tue, Dec 23, 2014 at 05:53:11PM +0200, Ahmed S. Darwish wrote:
> > From: Ahmed S. Darwish <ahmed.darwish@valeo.com>
> >
> > CAN to USB interfaces sold by the Swedish manufacturer Kvaser are
> > divided into two major families: 'Leaf', and 'UsbcanII'. From an
> > Operating System perspective, the firmware of both families behave
> > in a not too drastically different fashion.
> >
> > This patch adds support for the UsbcanII family of devices to the
> > current Kvaser Leaf-only driver.
> >
> > CAN frames sending, receiving, and error handling paths has been
> > tested using the dual-channel "Kvaser USBcan II HS/LS" dongle. It
> > should also work nicely with other products in the same category.
> >
>
> Good, thank you :-) I'll try to test the patch during the next
> week-end. Small remarks below.
>

Great! thanks and Merry Christmas :-)

> > Signed-off-by: Ahmed S. Darwish <ahmed.darwish@valeo.com>
> > ---
> > drivers/net/can/usb/kvaser_usb.c | 630 +++++++++++++++++++++++++++++++--------
> > 1 file changed, 505 insertions(+), 125 deletions(-)
> >
> > (Generated over 3.19.0-rc1 + generic bugfix at
> > can-kvaser_usb-Don-t-free-packets-when-tight-on-URBs.patch)
> >
> > diff --git a/drivers/net/can/usb/kvaser_usb.c b/drivers/net/can/usb/kvaser_usb.c
> > index 34c35d8..e7076da 100644
> > --- a/drivers/net/can/usb/kvaser_usb.c
> > +++ b/drivers/net/can/usb/kvaser_usb.c
> > @@ -6,12 +6,15 @@
> > * Parts of this driver are based on the following:
> > * - Kvaser linux leaf driver (version 4.78)
> > * - CAN driver for esd CAN-USB/2
> > + * - Kvaser linux usbcanII driver (version 5.3)
> > *
> > * Copyright (C) 2002-2006 KVASER AB, Sweden. All rights reserved.
> > * Copyright (C) 2010 Matthias Fuchs <matthias.fuchs@esd.eu>, esd gmbh
> > * Copyright (C) 2012 Olivier Sobrie <olivier@sobrie.be>
> > + * Copyright (C) 2014 Valeo Corporation
> > */
> >
> > +#include <linux/kernel.h>
> > #include <linux/completion.h>
> > #include <linux/module.h>
> > #include <linux/netdevice.h>
> > @@ -21,6 +24,18 @@
> > #include <linux/can/dev.h>
> > #include <linux/can/error.h>
> >
> > +#define MAX(a, b) ((a) > (b) ? (a) : (b))
>
> There is a max(a, b) macro in <linux/kernel.h>.
>

Quite true, but it unfortunately fails when the symbol is
used in array size declaration as in below:

struct kvaser_usb {
...
struct kvaser_usb_net_priv *nets[MAX_NET_DEVICES];
...
}

include/linux/kernel.h:713:19: error: braced-group within
expression allowed only inside a function
#define max(x, y) ({ \
^

> > +
> > +/*
> > + * Kvaser USB CAN dongles are divided into two major families:
> > + * - Leaf: Based on Renesas M32C, running firmware labeled as 'filo'
> > + * - UsbcanII: Based on Renesas M16C, running firmware labeled as 'helios'
> > + */
> > +enum kvaser_usb_family {
> > + KVASER_LEAF,
> > + KVASER_USBCAN,
> > +};
> > +
> > #define MAX_TX_URBS 16
> > #define MAX_RX_URBS 4
> > #define START_TIMEOUT 1000 /* msecs */
> > @@ -29,9 +44,12 @@
> > #define USB_RECV_TIMEOUT 1000 /* msecs */
> > #define RX_BUFFER_SIZE 3072
> > #define CAN_USB_CLOCK 8000000
> > -#define MAX_NET_DEVICES 3
> > +#define LEAF_MAX_NET_DEVICES 3
> > +#define USBCAN_MAX_NET_DEVICES 2
> > +#define MAX_NET_DEVICES MAX(LEAF_MAX_NET_DEVICES, \
> > + USBCAN_MAX_NET_DEVICES)
> >
> > -/* Kvaser USB devices */
> > +/* Leaf USB devices */
> > #define KVASER_VENDOR_ID 0x0bfd
> > #define USB_LEAF_DEVEL_PRODUCT_ID 10
> > #define USB_LEAF_LITE_PRODUCT_ID 11
> > @@ -55,6 +73,16 @@
> > #define USB_CAN_R_PRODUCT_ID 39
> > #define USB_LEAF_LITE_V2_PRODUCT_ID 288
> > #define USB_MINI_PCIE_HS_PRODUCT_ID 289
> > +#define LEAF_PRODUCT_ID(id) (id >= USB_LEAF_DEVEL_PRODUCT_ID && \
> > + id <= USB_MINI_PCIE_HS_PRODUCT_ID)
> > +
> > +/* USBCANII devices */
> > +#define USB_USBCAN_REVB_PRODUCT_ID 2
> > +#define USB_VCI2_PRODUCT_ID 3
> > +#define USB_USBCAN2_PRODUCT_ID 4
> > +#define USB_MEMORATOR_PRODUCT_ID 5
> > +#define USBCAN_PRODUCT_ID(id) (id >= USB_USBCAN_REVB_PRODUCT_ID && \
> > + id <= USB_MEMORATOR_PRODUCT_ID)
> >
> > /* USB devices features */
> > #define KVASER_HAS_SILENT_MODE BIT(0)
> > @@ -73,7 +101,7 @@
> > #define MSG_FLAG_TX_ACK BIT(6)
> > #define MSG_FLAG_TX_REQUEST BIT(7)
> >
> > -/* Can states */
> > +/* Can states (M16C CxSTRH register) */
> > #define M16C_STATE_BUS_RESET BIT(0)
> > #define M16C_STATE_BUS_ERROR BIT(4)
> > #define M16C_STATE_BUS_PASSIVE BIT(5)
> > @@ -98,7 +126,13 @@
> > #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_READ_CLOCK 30
> > +#define CMD_READ_CLOCK_REPLY 31
> > +
> > +#define LEAF_CMD_GET_CARD_INFO2 32
> > +#define USBCAN_CMD_RESET_CLOCK 32
> > +#define USBCAN_CMD_CLOCK_OVERFLOW_EVENT 33
> > +
> > #define CMD_GET_CARD_INFO 34
> > #define CMD_GET_CARD_INFO_REPLY 35
> > #define CMD_GET_SOFTWARE_INFO 38
> > @@ -108,8 +142,9 @@
> > #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
> > +
> > +#define LEAF_CMD_USB_THROTTLE 77
> > +#define LEAF_CMD_LOG_MESSAGE 106
> >
> > /* error factors */
> > #define M16C_EF_ACKE BIT(0)
> > @@ -121,6 +156,13 @@
> > #define M16C_EF_RCVE BIT(6)
> > #define M16C_EF_TRE BIT(7)
> >
> > +/* Only Leaf-based devices can report M16C error factors,
> > + * thus define our own error status flags for USBCAN */
> > +#define USBCAN_ERROR_STATE_NONE 0
> > +#define USBCAN_ERROR_STATE_TX_ERROR BIT(0)
> > +#define USBCAN_ERROR_STATE_RX_ERROR BIT(1)
> > +#define USBCAN_ERROR_STATE_BUSERROR BIT(2)
> > +
> > /* bittiming parameters */
> > #define KVASER_USB_TSEG1_MIN 1
> > #define KVASER_USB_TSEG1_MAX 16
> > @@ -137,7 +179,7 @@
> > #define KVASER_CTRL_MODE_SELFRECEPTION 3
> > #define KVASER_CTRL_MODE_OFF 4
> >
> > -/* log message */
> > +/* Extended CAN identifier flag */
> > #define KVASER_EXTENDED_FRAME BIT(31)
> >
> > struct kvaser_msg_simple {
> > @@ -148,30 +190,55 @@ struct kvaser_msg_simple {
> > struct kvaser_msg_cardinfo {
> > u8 tid;
> > u8 nchannels;
> > - __le32 serial_number;
> > - __le32 padding;
> > + union {
> > + struct {
> > + __le32 serial_number;
> > + __le32 padding;
> > + } __packed leaf0;
> > + struct {
> > + __le32 serial_number_low;
> > + __le32 serial_number_high;
> > + } __packed usbcan0;
> > + } __packed;
> > __le32 clock_resolution;
> > __le32 mfgdate;
> > u8 ean[8];
> > u8 hw_revision;
> > - u8 usb_hs_mode;
> > - __le16 padding2;
> > + union {
> > + struct {
> > + u8 usb_hs_mode;
> > + } __packed leaf1;
> > + struct {
> > + u8 padding;
> > + } __packed usbcan1;
> > + } __packed;
> > + __le16 padding;
> > } __packed;
> >
> > struct kvaser_msg_cardinfo2 {
> > u8 tid;
> > - u8 channel;
> > + u8 reserved;
> > u8 pcb_id[24];
> > __le32 oem_unlock_code;
> > } __packed;
> >
> > -struct kvaser_msg_softinfo {
> > +struct leaf_msg_softinfo {
> > u8 tid;
> > - u8 channel;
> > + u8 padding0;
> > __le32 sw_options;
> > __le32 fw_version;
> > __le16 max_outstanding_tx;
> > - __le16 padding[9];
> > + __le16 padding1[9];
> > +} __packed;
> > +
> > +struct usbcan_msg_softinfo {
> > + u8 tid;
> > + u8 fw_name[5];
> > + __le16 max_outstanding_tx;
> > + u8 padding[6];
> > + __le32 fw_version;
> > + __le16 checksum;
> > + __le16 sw_options;
> > } __packed;
> >
> > struct kvaser_msg_busparams {
> > @@ -188,36 +255,86 @@ struct kvaser_msg_tx_can {
> > u8 channel;
> > u8 tid;
> > u8 msg[14];
> > - u8 padding;
> > - u8 flags;
> > + union {
> > + struct {
> > + u8 padding;
> > + u8 flags;
> > + } __packed leaf;
> > + struct {
> > + u8 flags;
> > + u8 padding;
> > + } __packed usbcan;
> > + } __packed;
> > +} __packed;
> > +
> > +struct kvaser_msg_rx_can_header {
> > + u8 channel;
> > + u8 flag;
> > } __packed;
> >
> > -struct kvaser_msg_rx_can {
> > +struct leaf_msg_rx_can {
> > u8 channel;
> > u8 flag;
> > +
> > __le16 time[3];
> > u8 msg[14];
> > } __packed;
> >
> > -struct kvaser_msg_chip_state_event {
> > +struct usbcan_msg_rx_can {
> > + u8 channel;
> > + u8 flag;
> > +
> > + u8 msg[14];
> > + __le16 time;
> > +} __packed;
> > +
> > +struct leaf_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 {
> > +struct usbcan_msg_chip_state_event {
> > + u8 tid;
> > + u8 channel;
> > +
> > + u8 tx_errors_count;
> > + u8 rx_errors_count;
> > + __le16 time;
> > +
> > + u8 status;
> > + u8 padding[3];
> > +} __packed;
> > +
> > +struct kvaser_msg_tx_acknowledge_header {
> > + u8 channel;
> > + u8 tid;
> > +};
> > +
> > +struct leaf_msg_tx_acknowledge {
> > u8 channel;
> > u8 tid;
> > +
> > __le16 time[3];
> > u8 flags;
> > u8 time_offset;
> > } __packed;
> >
> > -struct kvaser_msg_error_event {
> > +struct usbcan_msg_tx_acknowledge {
> > + u8 channel;
> > + u8 tid;
> > +
> > + __le16 time;
> > + __le16 padding;
> > +} __packed;
> > +
> > +struct leaf_msg_error_event {
> > u8 tid;
> > u8 flags;
> > __le16 time[3];
> > @@ -229,6 +346,18 @@ struct kvaser_msg_error_event {
> > u8 error_factor;
> > } __packed;
> >
> > +struct usbcan_msg_error_event {
> > + u8 tid;
> > + u8 padding;
> > + u8 tx_errors_count_ch0;
> > + u8 rx_errors_count_ch0;
> > + u8 tx_errors_count_ch1;
> > + u8 rx_errors_count_ch1;
> > + u8 status_ch0;
> > + u8 status_ch1;
> > + __le16 time;
> > +} __packed;
> > +
> > struct kvaser_msg_ctrl_mode {
> > u8 tid;
> > u8 channel;
> > @@ -243,7 +372,7 @@ struct kvaser_msg_flush_queue {
> > u8 padding[3];
> > } __packed;
> >
> > -struct kvaser_msg_log_message {
> > +struct leaf_msg_log_message {
> > u8 channel;
> > u8 flags;
> > __le16 time[3];
> > @@ -260,19 +389,49 @@ struct kvaser_msg {
> > 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_rx_can_header rx_can_header;
> > + struct kvaser_msg_tx_acknowledge_header tx_acknowledge_header;
> > +
> > + union {
> > + struct leaf_msg_softinfo softinfo;
> > + struct leaf_msg_rx_can rx_can;
> > + struct leaf_msg_chip_state_event chip_state_event;
> > + struct leaf_msg_tx_acknowledge tx_acknowledge;
> > + struct leaf_msg_error_event error_event;
> > + struct leaf_msg_log_message log_message;
> > + } __packed leaf;
> > +
> > + union {
> > + struct usbcan_msg_softinfo softinfo;
> > + struct usbcan_msg_rx_can rx_can;
> > + struct usbcan_msg_chip_state_event chip_state_event;
> > + struct usbcan_msg_tx_acknowledge tx_acknowledge;
> > + struct usbcan_msg_error_event error_event;
> > + } __packed usbcan;
> > +
> > 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;
> >
> > +/* Leaf/USBCAN-agnostic summary of an error event.
> > + * No M16C error factors for USBCAN-based devices. */
> > +struct kvaser_error_summary {
> > + u8 channel, status, txerr, rxerr;
> > + union {
> > + struct {
> > + u8 error_factor;
> > + } leaf;
> > + struct {
> > + u8 other_ch_status;
> > + u8 error_state;
> > + } usbcan;
> > + };
> > +};
> > +
> > struct kvaser_usb_tx_urb_context {
> > struct kvaser_usb_net_priv *priv;
> > u32 echo_index;
> > @@ -288,6 +447,8 @@ struct kvaser_usb {
> >
> > u32 fw_version;
> > unsigned int nchannels;
> > + enum kvaser_usb_family family;
> > + unsigned int max_channels;
> >
> > bool rxinitdone;
> > void *rxbuf[MAX_RX_URBS];
> > @@ -311,6 +472,7 @@ struct kvaser_usb_net_priv {
> > };
> >
> > static const struct usb_device_id kvaser_usb_table[] = {
> > + /* Leaf family IDs */
> > { 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),
> > @@ -360,6 +522,17 @@ static const struct usb_device_id kvaser_usb_table[] = {
> > .driver_info = KVASER_HAS_TXRX_ERRORS },
> > { USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_LITE_V2_PRODUCT_ID) },
> > { USB_DEVICE(KVASER_VENDOR_ID, USB_MINI_PCIE_HS_PRODUCT_ID) },
> > +
> > + /* USBCANII family IDs */
> > + { USB_DEVICE(KVASER_VENDOR_ID, USB_USBCAN2_PRODUCT_ID),
> > + .driver_info = KVASER_HAS_TXRX_ERRORS },
> > + { USB_DEVICE(KVASER_VENDOR_ID, USB_USBCAN_REVB_PRODUCT_ID),
> > + .driver_info = KVASER_HAS_TXRX_ERRORS },
> > + { USB_DEVICE(KVASER_VENDOR_ID, USB_MEMORATOR_PRODUCT_ID),
> > + .driver_info = KVASER_HAS_TXRX_ERRORS },
> > + { USB_DEVICE(KVASER_VENDOR_ID, USB_VCI2_PRODUCT_ID),
> > + .driver_info = KVASER_HAS_TXRX_ERRORS },
> > +
> > { }
> > };
> > MODULE_DEVICE_TABLE(usb, kvaser_usb_table);
> > @@ -463,7 +636,18 @@ static int kvaser_usb_get_software_info(struct kvaser_usb *dev)
> > if (err)
> > return err;
> >
> > - dev->fw_version = le32_to_cpu(msg.u.softinfo.fw_version);
> > + switch (dev->family) {
> > + case KVASER_LEAF:
> > + dev->fw_version = le32_to_cpu(msg.u.leaf.softinfo.fw_version);
> > + break;
> > + case KVASER_USBCAN:
> > + dev->fw_version = le32_to_cpu(msg.u.usbcan.softinfo.fw_version);
> > + break;
> > + default:
> > + dev_err(dev->udev->dev.parent,
> > + "Invalid device family (%d)\n", dev->family);
> > + return -EINVAL;
> > + }
> >
> > return 0;
> > }
> > @@ -482,7 +666,7 @@ static int kvaser_usb_get_card_info(struct kvaser_usb *dev)
> > return err;
> >
> > dev->nchannels = msg.u.cardinfo.nchannels;
> > - if (dev->nchannels > MAX_NET_DEVICES)
> > + if (dev->nchannels > dev->max_channels)
> > return -EINVAL;
>
> IMHO, you can keep MAX_NET_DEVICES here.
>

The UsbcanII firmware hardcodes a maximum of 2 channels in
its protocol. This is unfortunately due to its inability to
tell whether an error event is from CAN channel 0 or ch 1,
and also due to its error_event format:

struct usbcan_msg_error_event {
u8 tid;
u8 padding;
u8 tx_errors_count_ch0;
u8 rx_errors_count_ch0;
u8 tx_errors_count_ch1;
u8 rx_errors_count_ch1;
u8 status_ch0;
u8 status_ch1;
__le16 time;
} __packed;

But since we have MAX_NET_DEVICES = 3, and given the above,
if the UsbcanII firmware reported to us having more than 2
channels, then it's:

a) most probably a memory corruption bug either in the firmware
or in the driver
b) an updated device/firmware we cannot support yet, since
we cannot arbitrate the origin of error events quite correctly
(especially in the case of CAN_ERR_BUSERROR, where the error
counters stays the same and we have to resort to other hacks.
Kindly check usbcan_report_error_if_applicable().)

So allowing more than 2 channels given the current set of
affairs will really induce correctness problems :-(

> >
> > return 0;
> > @@ -496,8 +680,10 @@ static void kvaser_usb_tx_acknowledge(const struct kvaser_usb *dev,
> > 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;
> > + u8 channel, tid;
> > +
> > + channel = msg->u.tx_acknowledge_header.channel;
> > + tid = msg->u.tx_acknowledge_header.tid;
> >
> > if (channel >= dev->nchannels) {
> > dev_err(dev->udev->dev.parent,
> > @@ -615,37 +801,83 @@ static void kvaser_usb_unlink_tx_urbs(struct kvaser_usb_net_priv *priv)
> > 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)
> > +static void kvaser_report_error_event(const struct kvaser_usb *dev,
> > + struct kvaser_error_summary *es);
> > +
> > +/*
> > + * Report error to userspace iff the controller's errors counter has
> > + * increased, or we're the only channel seeing the bus error state.
> > + *
> > + * As reported by USBCAN sheets, "the CAN controller has difficulties
> > + * to tell whether an error frame arrived on channel 1 or on channel 2."
> > + * Thus, error counters are compared with their earlier values to
> > + * determine which channel was responsible for the error event.
> > + */
> > +static void usbcan_report_error_if_applicable(const struct kvaser_usb *dev,
> > + struct kvaser_error_summary *es)
> > {
> > - 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;
> > + int old_tx_err_count, old_rx_err_count, channel, report_error;
> > +
> > + channel = es->channel;
> > + if (channel >= dev->nchannels) {
> > + dev_err(dev->udev->dev.parent,
> > + "Invalid channel number (%d)\n", channel);
> > + return;
> > + }
> > +
> > + priv = dev->nets[channel];
> > + old_tx_err_count = priv->bec.txerr;
> > + old_rx_err_count = priv->bec.rxerr;
> > +
> > + report_error = 0;
> > + if (es->txerr > old_tx_err_count) {
> > + es->usbcan.error_state |= USBCAN_ERROR_STATE_TX_ERROR;
> > + report_error = 1;
> > + }
> > + if (es->rxerr > old_rx_err_count) {
> > + es->usbcan.error_state |= USBCAN_ERROR_STATE_RX_ERROR;
> > + report_error = 1;
> > + }
> > + if ((es->status & M16C_STATE_BUS_ERROR) &&
> > + !(es->usbcan.other_ch_status & M16C_STATE_BUS_ERROR)) {
> > + es->usbcan.error_state |= USBCAN_ERROR_STATE_BUSERROR;
> > + report_error = 1;
> > + }
> > +
> > + if (report_error)
> > + kvaser_report_error_event(dev, es);
> > +}
> > +
> > +/*
> > + * Extract error summary from a Leaf-based device error message
> > + */
> > +static void leaf_extract_error_from_msg(const struct kvaser_usb *dev,
> > + const struct kvaser_msg *msg)
> > +{
> > + struct kvaser_error_summary es = { 0, };
> >
> > 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;
> > + es.channel = msg->u.leaf.error_event.channel;
> > + es.status = msg->u.leaf.error_event.status;
> > + es.txerr = msg->u.leaf.error_event.tx_errors_count;
> > + es.rxerr = msg->u.leaf.error_event.rx_errors_count;
> > + es.leaf.error_factor = msg->u.leaf.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];
> > + case LEAF_CMD_LOG_MESSAGE:
> > + es.channel = msg->u.leaf.log_message.channel;
> > + es.status = msg->u.leaf.log_message.data[0];
> > + es.txerr = msg->u.leaf.log_message.data[2];
> > + es.rxerr = msg->u.leaf.log_message.data[3];
> > + es.leaf.error_factor = msg->u.leaf.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;
> > + es.channel = msg->u.leaf.chip_state_event.channel;
> > + es.status = msg->u.leaf.chip_state_event.status;
> > + es.txerr = msg->u.leaf.chip_state_event.tx_errors_count;
> > + es.rxerr = msg->u.leaf.chip_state_event.rx_errors_count;
> > + es.leaf.error_factor = 0;
> > break;
> > default:
> > dev_err(dev->udev->dev.parent, "Invalid msg id (%d)\n",
> > @@ -653,16 +885,92 @@ static void kvaser_usb_rx_error(const struct kvaser_usb *dev,
> > return;
> > }
> >
> > - if (channel >= dev->nchannels) {
> > + kvaser_report_error_event(dev, &es);
> > +}
> > +
> > +/*
> > + * Extract summary from a USBCANII-based device error message.
> > + */
> > +static void usbcan_extract_error_from_msg(const struct kvaser_usb *dev,
> > + const struct kvaser_msg *msg)
> > +{
> > + struct kvaser_error_summary es = { 0, };
> > +
> > + switch (msg->id) {
> > +
> > + /* Sometimes errors are sent as unsolicited chip state events */
> > + case CMD_CHIP_STATE_EVENT:
> > + es.channel = msg->u.usbcan.chip_state_event.channel;
> > + es.status = msg->u.usbcan.chip_state_event.status;
> > + es.txerr = msg->u.usbcan.chip_state_event.tx_errors_count;
> > + es.rxerr = msg->u.usbcan.chip_state_event.rx_errors_count;
> > + usbcan_report_error_if_applicable(dev, &es);
> > + break;
> > +
> > + case CMD_CAN_ERROR_EVENT:
> > + es.channel = 0;
> > + es.status = msg->u.usbcan.error_event.status_ch0;
> > + es.txerr = msg->u.usbcan.error_event.tx_errors_count_ch0;
> > + es.rxerr = msg->u.usbcan.error_event.rx_errors_count_ch0;
> > + es.usbcan.other_ch_status =
> > + msg->u.usbcan.error_event.status_ch1;
> > + usbcan_report_error_if_applicable(dev, &es);
> > +
> > + /* For error events, the USBCAN firmware does not support
> > + * more than 2 channels: ch0, and ch1. */
> > + if (dev->nchannels > 1) {
> > + es.channel = 1;
> > + es.status = msg->u.usbcan.error_event.status_ch1;
> > + es.txerr = msg->u.usbcan.error_event.tx_errors_count_ch1;
> > + es.rxerr = msg->u.usbcan.error_event.rx_errors_count_ch1;
> > + es.usbcan.other_ch_status =
> > + msg->u.usbcan.error_event.status_ch0;
> > + usbcan_report_error_if_applicable(dev, &es);
> > + }
> > + break;
> > +
> > + default:
> > + dev_err(dev->udev->dev.parent, "Invalid msg id (%d)\n",
> > + msg->id);
> > + }
> > +}
> > +
> > +static void kvaser_usb_rx_error(const struct kvaser_usb *dev,
> > + const struct kvaser_msg *msg)
> > +{
> > + switch (dev->family) {
> > + case KVASER_LEAF:
> > + leaf_extract_error_from_msg(dev, msg);
> > + break;
> > + case KVASER_USBCAN:
> > + usbcan_extract_error_from_msg(dev, msg);
> > + break;
> > + default:
> > dev_err(dev->udev->dev.parent,
> > - "Invalid channel number (%d)\n", channel);
> > + "Invalid device family (%d)\n", dev->family);
> > return;
> > }
> > +}
> >
> > - priv = dev->nets[channel];
> > +static void kvaser_report_error_event(const struct kvaser_usb *dev,
> > + struct kvaser_error_summary *es)
> > +{
> > + struct can_frame *cf;
> > + struct sk_buff *skb;
> > + struct net_device_stats *stats;
> > + struct kvaser_usb_net_priv *priv;
> > + unsigned int new_state;
> > +
> > + if (es->channel >= dev->nchannels) {
> > + dev_err(dev->udev->dev.parent,
> > + "Invalid channel number (%d)\n", es->channel);
> > + return;
> > + }
> > +
> > + priv = dev->nets[es->channel];
> > stats = &priv->netdev->stats;
> >
> > - if (status & M16C_STATE_BUS_RESET) {
> > + if (es->status & M16C_STATE_BUS_RESET) {
> > kvaser_usb_unlink_tx_urbs(priv);
> > return;
> > }
> > @@ -675,9 +983,9 @@ static void kvaser_usb_rx_error(const struct kvaser_usb *dev,
> >
> > new_state = priv->can.state;
> >
> > - netdev_dbg(priv->netdev, "Error status: 0x%02x\n", status);
> > + netdev_dbg(priv->netdev, "Error status: 0x%02x\n", es->status);
> >
> > - if (status & M16C_STATE_BUS_OFF) {
> > + if (es->status & M16C_STATE_BUS_OFF) {
> > cf->can_id |= CAN_ERR_BUSOFF;
> >
> > priv->can.can_stats.bus_off++;
> > @@ -687,12 +995,12 @@ static void kvaser_usb_rx_error(const struct kvaser_usb *dev,
> > netif_carrier_off(priv->netdev);
> >
> > new_state = CAN_STATE_BUS_OFF;
> > - } else if (status & M16C_STATE_BUS_PASSIVE) {
> > + } else if (es->status & M16C_STATE_BUS_PASSIVE) {
> > if (priv->can.state != CAN_STATE_ERROR_PASSIVE) {
> > cf->can_id |= CAN_ERR_CRTL;
> >
> > - if (txerr || rxerr)
> > - cf->data[1] = (txerr > rxerr)
> > + if (es->txerr || es->rxerr)
> > + cf->data[1] = (es->txerr > es->rxerr)
> > ? CAN_ERR_CRTL_TX_PASSIVE
> > : CAN_ERR_CRTL_RX_PASSIVE;
> > else
> > @@ -703,13 +1011,11 @@ static void kvaser_usb_rx_error(const struct kvaser_usb *dev,
> > }
> >
> > new_state = CAN_STATE_ERROR_PASSIVE;
> > - }
> > -
> > - if (status == M16C_STATE_BUS_ERROR) {
> > + } else if (es->status & M16C_STATE_BUS_ERROR) {
> > if ((priv->can.state < CAN_STATE_ERROR_WARNING) &&
> > - ((txerr >= 96) || (rxerr >= 96))) {
> > + ((es->txerr >= 96) || (es->rxerr >= 96))) {
> > cf->can_id |= CAN_ERR_CRTL;
> > - cf->data[1] = (txerr > rxerr)
> > + cf->data[1] = (es->txerr > es->rxerr)
> > ? CAN_ERR_CRTL_TX_WARNING
> > : CAN_ERR_CRTL_RX_WARNING;
> >
> > @@ -723,7 +1029,7 @@ static void kvaser_usb_rx_error(const struct kvaser_usb *dev,
> > }
> > }
> >
> > - if (!status) {
> > + if (!es->status) {
> > cf->can_id |= CAN_ERR_PROT;
> > cf->data[2] = CAN_ERR_PROT_ACTIVE;
> >
> > @@ -739,34 +1045,52 @@ static void kvaser_usb_rx_error(const struct kvaser_usb *dev,
> > priv->can.can_stats.restarts++;
> > }
> >
> > - if (error_factor) {
> > - priv->can.can_stats.bus_error++;
> > - stats->rx_errors++;
> > -
> > - cf->can_id |= CAN_ERR_BUSERROR | 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;
> > + switch (dev->family) {
> > + case KVASER_LEAF:
> > + if (es->leaf.error_factor) {
> > + priv->can.can_stats.bus_error++;
> > + stats->rx_errors++;
> > +
> > + cf->can_id |= CAN_ERR_BUSERROR | CAN_ERR_PROT;
> > +
> > + if (es->leaf.error_factor & M16C_EF_ACKE)
> > + cf->data[3] |= (CAN_ERR_PROT_LOC_ACK);
> > + if (es->leaf.error_factor & M16C_EF_CRCE)
> > + cf->data[3] |= (CAN_ERR_PROT_LOC_CRC_SEQ |
> > + CAN_ERR_PROT_LOC_CRC_DEL);
> > + if (es->leaf.error_factor & M16C_EF_FORME)
> > + cf->data[2] |= CAN_ERR_PROT_FORM;
> > + if (es->leaf.error_factor & M16C_EF_STFE)
> > + cf->data[2] |= CAN_ERR_PROT_STUFF;
> > + if (es->leaf.error_factor & M16C_EF_BITE0)
> > + cf->data[2] |= CAN_ERR_PROT_BIT0;
> > + if (es->leaf.error_factor & M16C_EF_BITE1)
> > + cf->data[2] |= CAN_ERR_PROT_BIT1;
> > + if (es->leaf.error_factor & M16C_EF_TRE)
> > + cf->data[2] |= CAN_ERR_PROT_TX;
> > + }
> > + break;
> > + case KVASER_USBCAN:
> > + if (es->usbcan.error_state & USBCAN_ERROR_STATE_TX_ERROR)
> > + stats->tx_errors++;
> > + if (es->usbcan.error_state & USBCAN_ERROR_STATE_RX_ERROR)
> > + stats->rx_errors++;
> > + if (es->usbcan.error_state & USBCAN_ERROR_STATE_BUSERROR) {
> > + priv->can.can_stats.bus_error++;
> > + cf->can_id |= CAN_ERR_BUSERROR;
> > + }
> > + break;
> > + default:
> > + dev_err(dev->udev->dev.parent,
> > + "Invalid device family (%d)\n", dev->family);
> > + goto err;
> > }
> >
> > - cf->data[6] = txerr;
> > - cf->data[7] = rxerr;
> > + cf->data[6] = es->txerr;
> > + cf->data[7] = es->rxerr;
> >
> > - priv->bec.txerr = txerr;
> > - priv->bec.rxerr = rxerr;
> > + priv->bec.txerr = es->txerr;
> > + priv->bec.rxerr = es->rxerr;
> >
> > priv->can.state = new_state;
> >
> > @@ -774,6 +1098,11 @@ static void kvaser_usb_rx_error(const struct kvaser_usb *dev,
> >
> > stats->rx_packets++;
> > stats->rx_bytes += cf->can_dlc;
> > +
> > + return;
> > +
> > +err:
> > + dev_kfree_skb(skb);
> > }
> >
> > static void kvaser_usb_rx_can_err(const struct kvaser_usb_net_priv *priv,
> > @@ -783,16 +1112,16 @@ static void kvaser_usb_rx_can_err(const struct kvaser_usb_net_priv *priv,
> > struct sk_buff *skb;
> > struct net_device_stats *stats = &priv->netdev->stats;
> >
> > - if (msg->u.rx_can.flag & (MSG_FLAG_ERROR_FRAME |
> > + if (msg->u.rx_can_header.flag & (MSG_FLAG_ERROR_FRAME |
> > MSG_FLAG_NERR)) {
> > netdev_err(priv->netdev, "Unknow error (flags: 0x%02x)\n",
> > - msg->u.rx_can.flag);
> > + msg->u.rx_can_header.flag);
> >
> > stats->rx_errors++;
> > return;
> > }
> >
> > - if (msg->u.rx_can.flag & MSG_FLAG_OVERRUN) {
> > + if (msg->u.rx_can_header.flag & MSG_FLAG_OVERRUN) {
> > skb = alloc_can_err_skb(priv->netdev, &cf);
> > if (!skb) {
> > stats->rx_dropped++;
> > @@ -819,7 +1148,8 @@ static void kvaser_usb_rx_can_msg(const struct kvaser_usb *dev,
> > struct can_frame *cf;
> > struct sk_buff *skb;
> > struct net_device_stats *stats;
> > - u8 channel = msg->u.rx_can.channel;
> > + u8 channel = msg->u.rx_can_header.channel;
> > + const u8 *rx_msg;
> >
> > if (channel >= dev->nchannels) {
> > dev_err(dev->udev->dev.parent,
> > @@ -830,19 +1160,32 @@ static void kvaser_usb_rx_can_msg(const struct kvaser_usb *dev,
> > priv = dev->nets[channel];
> > stats = &priv->netdev->stats;
> >
> > - if ((msg->u.rx_can.flag & MSG_FLAG_ERROR_FRAME) &&
> > - (msg->id == CMD_LOG_MESSAGE)) {
> > + if ((msg->u.rx_can_header.flag & MSG_FLAG_ERROR_FRAME) &&
> > + (dev->family == KVASER_LEAF && msg->id == LEAF_CMD_LOG_MESSAGE)) {
> > kvaser_usb_rx_error(dev, msg);
> > return;
> > - } else if (msg->u.rx_can.flag & (MSG_FLAG_ERROR_FRAME |
> > - MSG_FLAG_NERR |
> > - MSG_FLAG_OVERRUN)) {
> > + } else if (msg->u.rx_can_header.flag & (MSG_FLAG_ERROR_FRAME |
> > + MSG_FLAG_NERR |
> > + MSG_FLAG_OVERRUN)) {
> > kvaser_usb_rx_can_err(priv, msg);
> > return;
> > - } else if (msg->u.rx_can.flag & ~MSG_FLAG_REMOTE_FRAME) {
> > + } else if (msg->u.rx_can_header.flag & ~MSG_FLAG_REMOTE_FRAME) {
> > netdev_warn(priv->netdev,
> > "Unhandled frame (flags: 0x%02x)",
> > - msg->u.rx_can.flag);
> > + msg->u.rx_can_header.flag);
> > + return;
> > + }
> > +
> > + switch (dev->family) {
> > + case KVASER_LEAF:
> > + rx_msg = msg->u.leaf.rx_can.msg;
> > + break;
> > + case KVASER_USBCAN:
> > + rx_msg = msg->u.usbcan.rx_can.msg;
> > + break;
> > + default:
> > + dev_err(dev->udev->dev.parent,
> > + "Invalid device family (%d)\n", dev->family);
> > return;
> > }
> >
> > @@ -852,38 +1195,37 @@ static void kvaser_usb_rx_can_msg(const struct kvaser_usb *dev,
> > return;
> > }
> >
> > - if (msg->id == CMD_LOG_MESSAGE) {
> > - cf->can_id = le32_to_cpu(msg->u.log_message.id);
> > + if (dev->family == KVASER_LEAF && msg->id == LEAF_CMD_LOG_MESSAGE) {
> > + cf->can_id = le32_to_cpu(msg->u.leaf.log_message.id);
> > if (cf->can_id & KVASER_EXTENDED_FRAME)
> > cf->can_id &= CAN_EFF_MASK | CAN_EFF_FLAG;
> > else
> > cf->can_id &= CAN_SFF_MASK;
> >
> > - cf->can_dlc = get_can_dlc(msg->u.log_message.dlc);
> > + cf->can_dlc = get_can_dlc(msg->u.leaf.log_message.dlc);
> >
> > - if (msg->u.log_message.flags & MSG_FLAG_REMOTE_FRAME)
> > + if (msg->u.leaf.log_message.flags & MSG_FLAG_REMOTE_FRAME)
> > cf->can_id |= CAN_RTR_FLAG;
> > else
> > - memcpy(cf->data, &msg->u.log_message.data,
> > + memcpy(cf->data, &msg->u.leaf.log_message.data,
> > cf->can_dlc);
> > } else {
> > - cf->can_id = ((msg->u.rx_can.msg[0] & 0x1f) << 6) |
> > - (msg->u.rx_can.msg[1] & 0x3f);
> > + cf->can_id = ((rx_msg[0] & 0x1f) << 6) | (rx_msg[1] & 0x3f);
> >
> > 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 |= ((rx_msg[2] & 0x0f) << 14) |
> > + ((rx_msg[3] & 0xff) << 6) |
> > + (rx_msg[4] & 0x3f);
> > cf->can_id |= CAN_EFF_FLAG;
> > }
> >
> > - cf->can_dlc = get_can_dlc(msg->u.rx_can.msg[5]);
> > + cf->can_dlc = get_can_dlc(rx_msg[5]);
> >
> > - if (msg->u.rx_can.flag & MSG_FLAG_REMOTE_FRAME)
> > + if (msg->u.rx_can_header.flag & MSG_FLAG_REMOTE_FRAME)
> > cf->can_id |= CAN_RTR_FLAG;
> > else
> > - memcpy(cf->data, &msg->u.rx_can.msg[6],
> > + memcpy(cf->data, &rx_msg[6],
> > cf->can_dlc);
> > }
> >
> > @@ -947,7 +1289,12 @@ static void kvaser_usb_handle_message(const struct kvaser_usb *dev,
> >
> > case CMD_RX_STD_MESSAGE:
> > case CMD_RX_EXT_MESSAGE:
> > - case CMD_LOG_MESSAGE:
> > + kvaser_usb_rx_can_msg(dev, msg);
> > + break;
> > +
> > + case LEAF_CMD_LOG_MESSAGE:
> > + if (dev->family != KVASER_LEAF)
> > + goto warn;
> > kvaser_usb_rx_can_msg(dev, msg);
> > break;
> >
> > @@ -960,8 +1307,14 @@ static void kvaser_usb_handle_message(const struct kvaser_usb *dev,
> > kvaser_usb_tx_acknowledge(dev, msg);
> > break;
> >
> > + /* Ignored messages */
> > + case USBCAN_CMD_CLOCK_OVERFLOW_EVENT:
> > + if (dev->family != KVASER_USBCAN)
> > + goto warn;
> > + break;
> > +
> > default:
> > - dev_warn(dev->udev->dev.parent,
> > +warn: dev_warn(dev->udev->dev.parent,
> > "Unhandled message (%d)\n", msg->id);
> > break;
> > }
> > @@ -1181,7 +1534,7 @@ static void kvaser_usb_unlink_all_urbs(struct kvaser_usb *dev)
> > dev->rxbuf[i],
> > dev->rxbuf_dma[i]);
> >
> > - for (i = 0; i < MAX_NET_DEVICES; i++) {
> > + for (i = 0; i < dev->max_channels; i++) {
>
> here too... or replace it by nchannels.
>

Yes, indeed. nchannels is the correct choice here, especially since
kvaser_usb_init_one() is called "dev->nchannels" times too.

> > struct kvaser_usb_net_priv *priv = dev->nets[i];
> >
> > if (priv)
> > @@ -1286,6 +1639,7 @@ static netdev_tx_t kvaser_usb_start_xmit(struct sk_buff *skb,
> > struct kvaser_msg *msg;
> > int i, err;
> > int ret = NETDEV_TX_OK;
> > + uint8_t *msg_tx_can_flags;
> > bool kfree_skb_on_error = true;
> >
> > if (can_dropped_invalid_skb(netdev, skb))
> > @@ -1306,9 +1660,23 @@ static netdev_tx_t kvaser_usb_start_xmit(struct sk_buff *skb,
> >
> > msg = buf;
> > msg->len = MSG_HEADER_LEN + sizeof(struct kvaser_msg_tx_can);
> > - msg->u.tx_can.flags = 0;
> > msg->u.tx_can.channel = priv->channel;
> >
> > + switch (dev->family) {
> > + case KVASER_LEAF:
> > + msg_tx_can_flags = &msg->u.tx_can.leaf.flags;
> > + break;
> > + case KVASER_USBCAN:
> > + msg_tx_can_flags = &msg->u.tx_can.usbcan.flags;
> > + break;
> > + default:
> > + dev_err(dev->udev->dev.parent,
> > + "Invalid device family (%d)\n", dev->family);
> > + goto releasebuf;
> > + }
> > +
> > + *msg_tx_can_flags = 0;
> > +
> > if (cf->can_id & CAN_EFF_FLAG) {
> > msg->id = CMD_TX_EXT_MESSAGE;
> > msg->u.tx_can.msg[0] = (cf->can_id >> 24) & 0x1f;
> > @@ -1326,7 +1694,7 @@ static netdev_tx_t kvaser_usb_start_xmit(struct sk_buff *skb,
> > 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;
> > + *msg_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) {
> > @@ -1596,6 +1964,18 @@ static int kvaser_usb_probe(struct usb_interface *intf,
> > if (!dev)
> > return -ENOMEM;
> >
> > + if (LEAF_PRODUCT_ID(id->idProduct)) {
> > + dev->family = KVASER_LEAF;
> > + dev->max_channels = LEAF_MAX_NET_DEVICES;
> > + } else if (USBCAN_PRODUCT_ID(id->idProduct)) {
> > + dev->family = KVASER_USBCAN;
> > + dev->max_channels = USBCAN_MAX_NET_DEVICES;
> > + } else {
> > + dev_err(&intf->dev, "Product ID (%d) does not belong to any "
> > + "known Kvaser USB family", id->idProduct);
> > + return -ENODEV;
> > + }
> > +
>
> Is it really required to keep max_channels in the kvaser_usb structure?
> If I looked correctly, you use this variable as a replacement for
> MAX_NET_DEVICES in the code and MAX_NET_DEVICES is only used in probe
> and disconnect functions. I think it can even be replaced by nchannels
> in the disconnect path. So I also think that it don't need to be in the
> kvaser_usb structure.
>

hmmm.. given the current state of error arbitration explained
above, where I cannot accept a dev->nchannels > 2, I guess we
have two options:

a) Remove max_channels, and hardcode the channels count
correctness logic as follows:

dev->nchannels = msg.u.cardinfo.nchannels;
if ((dev->family == USBCAN && dev->nchannels > USBCAN_MAX_NET_DEVICES)
|| (dev->family == LEAF && dev->nchannels > LEAF_MAX_NET_DEVICES))
return -EINVAL

b) Leave max_channels in 'struct kvaser_usb' as is.

I personally prefer the solution at 'b)' but I can do it as
in 'a)' if you prefer :-)

> > err = kvaser_usb_get_endpoints(intf, &dev->bulk_in, &dev->bulk_out);
> > if (err) {
> > dev_err(&intf->dev, "Cannot get usb endpoint(s)");
> > @@ -1608,7 +1988,7 @@ static int kvaser_usb_probe(struct usb_interface *intf,
> >
> > usb_set_intfdata(intf, dev);
> >
> > - for (i = 0; i < MAX_NET_DEVICES; i++)
> > + for (i = 0; i < dev->max_channels; i++)
> > kvaser_usb_send_simple_msg(dev, CMD_RESET_CHIP, i);
>
> Someone reported me that recent leaf firmwares go in trouble when
> you send a command for a channel that does not exist. Instead of
> max_channels, you can use nchannels here and move the reset command
> in the kvaser_usb_init_one() function.
> I've a patch for this but It is not tested yet. I'll send it next week-end after
> I did some tests.
>

Great. I guess I can submit a 3-patch series now
(kfree_skb fix + the above fix + driver).

> >
> > err = kvaser_usb_get_software_info(dev);
>
> Thank you,
>

Thanks a lot for your review.

P.S. the Gmail mailer you've used messed badly with the patch
code identation; I had to manually restore it back to make the
discussion meaningful for others :-)

Regards,
--
Darwish