]> rtime.felk.cvut.cz Git - lincan.git/blobdiff - lincan/src/usbcan.c
Added initialization of struct usbcan_message flags when receiving and transmitting...
[lincan.git] / lincan / src / usbcan.c
index f29e549b496cc87dd28891a23f0a0e0aad0041d4..70e0a84609f068999affc6a7e3654e9bc6d4e425 100644 (file)
 #include "../include/devcommon.h"
 #include "../include/setup.h"
 #include "../include/usbcan.h"
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,20))
+ #include <linux/freezer.h>
+#endif
+#include <linux/smp_lock.h>
 
 static int usbcan_probe(struct usb_interface *interface, const struct usb_device_id *id);
 static void usbcan_disconnect(struct usb_interface *interface);
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,10))
+void release_device(struct kref *refcount);
+#else
+void release_device(struct candevice_t *candev);
+#endif
 
 volatile int usbcan_chip_count=0;
 
@@ -156,7 +165,6 @@ int usbcan_program_irq(struct candevice_t *candev)
        return 0;
 }
 
-/* !!! Don't change this function !!! */
 int usbcan_register(struct hwspecops_t *hwspecops)
 {
        hwspecops->request_io = usbcan_request_io;
@@ -168,17 +176,21 @@ int usbcan_register(struct hwspecops_t *hwspecops)
        hwspecops->write_register = NULL;
        hwspecops->read_register = NULL;
        hwspecops->program_irq = usbcan_program_irq;
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,10))
+       hwspecops->release_device = release_device;
+#endif
        return 0;
 }
 
 // static int sja1000_report_error_limit_counter;
 
-static void sja1000_report_error(struct canchip_t *chip,
+static void usbcan_report_error(struct canchip_t *chip,
                                unsigned sr, unsigned ir, unsigned ecc)
 {
        /*TODO : Error reporting from device */
 
-/*     if(sja1000_report_error_limit_counter>=100)
+#if 0
+       if(sja1000_report_error_limit_counter>=100)
                return;
 
        CANMSG("Error: status register: 0x%x irq_register: 0x%02x error: 0x%02x\n",
@@ -211,6 +223,7 @@ static void sja1000_report_error(struct canchip_t *chip,
                      );
        }
 #endif /*CONFIG_OC_LINCAN_DETAILED_ERRORS*/
+#endif
 }
 
 
@@ -263,7 +276,7 @@ int usbcan_extended_mask(struct canchip_t *chip, unsigned long code, unsigned  l
        int retval;
        struct usbcan_usb *dev=(struct usbcan_usb*)chip->chip_data;
 
-       u8 usbbuf[16];
+       u8 usbbuf[USBCAN_TRANSFER_SIZE];
 
        if (!dev)
                return -ENODEV;
@@ -276,7 +289,7 @@ int usbcan_extended_mask(struct canchip_t *chip, unsigned long code, unsigned  l
                USBCAN_VENDOR_EXT_MASK_SET,
                USB_TYPE_VENDOR,
                cpu_to_le16(0), cpu_to_le16(chip->chip_idx),
-               &usbbuf, 16,
+               &usbbuf, USBCAN_TRANSFER_SIZE,
                10000);
        if (retval<0)
                return -ENODEV;
@@ -286,7 +299,7 @@ int usbcan_extended_mask(struct canchip_t *chip, unsigned long code, unsigned  l
                USBCAN_VENDOR_EXT_MASK_STATUS,
                USB_TYPE_VENDOR,
                cpu_to_le16(0), cpu_to_le16(chip->chip_idx),
-               &usbbuf, 16,
+               &usbbuf, USBCAN_TRANSFER_SIZE,
                10000);
 
        if (retval==1){
@@ -319,7 +332,7 @@ int usbcan_baud_rate(struct canchip_t *chip, int rate, int clock, int sjw,
        int retval;
        struct usbcan_usb *dev=(struct usbcan_usb*)chip->chip_data;
 
-       u8 usbbuf[16];
+       u8 usbbuf[USBCAN_TRANSFER_SIZE];
 
        if (!dev)
                return -ENODEV;
@@ -334,7 +347,7 @@ int usbcan_baud_rate(struct canchip_t *chip, int rate, int clock, int sjw,
                USBCAN_VENDOR_BAUD_RATE_SET,
                USB_TYPE_VENDOR,
                cpu_to_le16(0), cpu_to_le16(chip->chip_idx),
-               &usbbuf, 16,
+               &usbbuf, USBCAN_TRANSFER_SIZE,
                10000);
        if (retval<0)
                return -ENODEV;
@@ -344,7 +357,7 @@ int usbcan_baud_rate(struct canchip_t *chip, int rate, int clock, int sjw,
                USBCAN_VENDOR_BAUD_RATE_STATUS,
                USB_TYPE_VENDOR,
                cpu_to_le16(0), cpu_to_le16(chip->chip_idx),
-               usbbuf, 16,
+               usbbuf, USBCAN_TRANSFER_SIZE,
                10000);
 
        if (retval==1){
@@ -388,38 +401,6 @@ int usbcan_pre_read_config(struct canchip_t *chip, struct msgobj_t *obj)
 int usbcan_pre_write_config(struct canchip_t *chip, struct msgobj_t *obj,
                                                        struct canmsg_t *msg)
 {
-       struct usbcan_usb *dev=(struct usbcan_usb*)chip->chip_data;
-       int i=0;
-       int len;
-       u8 *ptr;
-
-       if (!dev)
-               return -ENODEV;
-       /* Wait until Transmit Buffer Status is released */
-       while ( usbcan_chip_queue_status(chip) &&
-                                               i++<MAX_TRANSMIT_WAIT_LOOPS) {
-               udelay(i);
-       }
-       if (usbcan_chip_queue_status(chip)){
-               CANMSG("Buffer full, cannot send message\n");
-               return -EIO;
-       }
-
-       *(uint8_t *)(dev->tx_msg)=chip->chip_idx & 0xFF;
-
-       len = msg->length;
-       if(len > CAN_MSG_LENGTH) len = CAN_MSG_LENGTH;
-
-       *(uint8_t *)(dev->tx_msg+1)=len & 0xFF;
-       *(uint16_t *)(dev->tx_msg+2)=cpu_to_le16(msg->flags);
-       *(uint32_t *)(dev->tx_msg+4)=cpu_to_le32(msg->id);
-
-       for(ptr=dev->tx_msg+8,i=0; i < len; ptr++,i++) {
-               *ptr=msg->data[i] & 0xFF;
-       }
-       for(; i < 8; ptr++,i++) {
-               *ptr=0;
-       }
        return 0;
 }
 
@@ -437,43 +418,6 @@ int usbcan_pre_write_config(struct canchip_t *chip, struct msgobj_t *obj,
 int usbcan_send_msg(struct canchip_t *chip, struct msgobj_t *obj,
                                                        struct canmsg_t *msg)
 {
-       struct usbcan_usb *dev=(struct usbcan_usb*)chip->chip_data;
-       int len,retval;
-
-       if (!dev)
-               return -ENODEV;
-
-       set_bit(USBCAN_TX_PENDING,&dev->flags);
-       retval=usb_bulk_msg(dev->udev,
-                       usb_sndbulkpipe(dev->udev, dev->bulk_out_endpointAddr),
-                       &dev->tx_msg, 16,
-                       &len,10000);
-       clear_bit(USBCAN_TX_PENDING,&dev->flags);
-       if (retval){
-               CANMSG("URB error %d\n",retval);
-               return -EIO;
-       }
-       if (len!=16){
-               CANMSG("CAN message not sent\n");
-               return -EIO;
-       }
-       CANMSG("Message sent\n");
-
-       if(obj->tx_slot){
-               // Do local transmitted message distribution if enabled
-               if (processlocal){
-                       // fill CAN message timestamp
-                       can_filltimestamp(&obj->tx_slot->msg.timestamp);
-
-                       obj->tx_slot->msg.flags |= MSG_LOCAL;
-                       canque_filter_msg2edges(obj->qends, &obj->tx_slot->msg);
-               }
-               // Free transmitted slot
-               canque_free_outslot(obj->qends, obj->tx_qedge, obj->tx_slot);
-               obj->tx_slot=NULL;
-       }
-
-       can_msgobj_clear_fl(obj,TX_PENDING);
        return 0;
 }
 
@@ -509,7 +453,7 @@ int usbcan_set_btregs(struct canchip_t *chip, unsigned short btr0,
                                                        unsigned short btr1)
 {
        int retval;
-       u8      buf[16];
+       u8      buf[USBCAN_TRANSFER_SIZE];
        struct usbcan_usb *dev=(struct usbcan_usb*)chip->chip_data;
        uint16_t value=(btr1&0xFF)<<8 | (btr0&0xFF);
 
@@ -521,7 +465,7 @@ int usbcan_set_btregs(struct canchip_t *chip, unsigned short btr0,
        USBCAN_VENDOR_SET_BTREGS,
        USB_TYPE_VENDOR,
        cpu_to_le16(value), cpu_to_le16(chip->chip_idx),
-       &buf, 16,
+       &buf, USBCAN_TRANSFER_SIZE,
        10000);
 
        if (retval==1){
@@ -541,7 +485,7 @@ int usbcan_set_btregs(struct canchip_t *chip, unsigned short btr0,
 int usbcan_start_chip(struct canchip_t *chip)
 {
        int retval;
-       u8      buf[16];
+       u8      buf[USBCAN_TRANSFER_SIZE];
        struct usbcan_usb *dev=(struct usbcan_usb*)chip->chip_data;
 
        if (!dev)
@@ -552,7 +496,7 @@ int usbcan_start_chip(struct canchip_t *chip)
        USBCAN_VENDOR_START_CHIP,
        USB_TYPE_VENDOR,
        cpu_to_le16(0), cpu_to_le16(chip->chip_idx),
-       &buf, 16,
+       &buf, USBCAN_TRANSFER_SIZE,
        10000);
 
        if (retval==1){
@@ -574,7 +518,7 @@ int usbcan_start_chip(struct canchip_t *chip)
 int usbcan_chip_queue_status(struct canchip_t *chip)
 {
        int retval;
-       u8      buf[16];
+       u8      buf[USBCAN_TRANSFER_SIZE];
        struct usbcan_usb *dev=(struct usbcan_usb*)chip->chip_data;
 
        if (!dev)
@@ -584,11 +528,11 @@ int usbcan_chip_queue_status(struct canchip_t *chip)
        USBCAN_VENDOR_CHECK_TX_STAT,
        USB_TYPE_VENDOR,
        cpu_to_le16(0), cpu_to_le16(chip->chip_idx),
-       &buf, 16,
+       &buf, USBCAN_TRANSFER_SIZE,
        10000);
 
        if (retval==1){
-               CANMSG("Chip_queue_status: %d\n",buf[0]);
+               DEBUGMSG("Chip_queue_status: %d\n",buf[0]);
                if(buf[0]==1)
                        return 0;
                if(buf[0]==0)
@@ -608,7 +552,7 @@ int usbcan_chip_queue_status(struct canchip_t *chip)
 int usbcan_stop_chip(struct canchip_t *chip)
 {
        int retval;
-       u8      buf[16];
+       u8      buf[USBCAN_TRANSFER_SIZE];
        struct usbcan_usb *dev=(struct usbcan_usb*)chip->chip_data;
 
        if (!dev)
@@ -619,7 +563,7 @@ int usbcan_stop_chip(struct canchip_t *chip)
        USBCAN_VENDOR_STOP_CHIP,
        USB_TYPE_VENDOR,
        cpu_to_le16(0), cpu_to_le16(chip->chip_idx),
-       &buf, 16,
+       &buf, USBCAN_TRANSFER_SIZE,
        10000);
 
        if (retval==1){
@@ -636,19 +580,20 @@ int usbcan_stop_chip(struct canchip_t *chip)
  *
  * File: src/usbcan.c
  */
-void usbcan_register_devs(struct canchip_t *chip,void *data){
+int usbcan_register_devs(struct canchip_t *chip,void *data){
        struct usbcan_devs *usbdevs=(struct usbcan_devs *)data;
        if (!usbdevs){
            CANMSG("Bad structure given\n");
-           return;
+           return -1;
        }
        if (chip->chip_idx>=usbdevs->count) {
            CANMSG("Requested chip number is bigger than chip count\n");
-           return;
+           return -1;
        }
 
        usbdevs->devs[chip->chip_idx]->chip=chip;
        chip->chip_data=(void *)usbdevs->devs[chip->chip_idx];
+       return 0;
 }
 
 /**
@@ -663,7 +608,7 @@ int usbcan_attach_to_chip(struct canchip_t *chip)
        struct usbcan_usb *dev = (struct usbcan_usb *)chip->chip_data;
 
        /* start kernel thread */
-       dev->comthread=can_kthread_run(usbcan_read_kthread, (void *)dev, "usbcan_%d",chip->chip_idx);
+       dev->comthread=can_kthread_run(usbcan_kthread, (void *)dev, "usbcan_%d",chip->chip_idx);
 
        return 0;
 }
@@ -682,7 +627,9 @@ int usbcan_release_chip(struct canchip_t *chip)
        usbcan_stop_chip(chip);
 
        /* terminate the kernel thread */
-       can_kthread_stop(dev->comthread);
+       set_bit(USBCAN_TERMINATE,&dev->flags);
+//     wake_up_process(dev->comthread);
+       can_kthread_stop(dev->comthread);
 
        return 0;
 }
@@ -744,54 +691,183 @@ int usbcan_config_irqs(struct canchip_t *chip, short irqs)
        return -ENOSYS;
 }
 
+
+static void usbcan_usb_message_move_list(struct usbcan_usb *dev,
+                       struct usbcan_message *m, struct list_head *head)
+{
+       can_spin_irqflags_t flags;
+       can_spin_lock_irqsave(&dev->list_lock, flags);
+       list_del(&m->list_node);
+       list_add_tail(&m->list_node, head);
+       can_spin_unlock_irqrestore(&dev->list_lock, flags);
+}
+
+
 /**
- * usbcan_irq_write_handler: - part of ISR code responsible for transmit events
- * @chip: pointer to chip state structure
- * @obj: pointer to attached queue description
+ * usbcan_kthread_read_handler: - part of kthread code responsible for receive completed events
+ * @dev: pointer to usb device related structure
+ * @obj: pointer to attached message object description
  *
- * The main purpose of this function is to read message from attached queues
- * and transfer message contents into CAN controller chip.
+ * The main purpose of this function is to read message from usb urb
+ * and transfer message contents to CAN queue ends.
  * This subroutine is called by
- * usbcan_irq_write_handler() for transmit events.
+ * usbcan_kthread().
  * File: src/usbcan.c
  */
-void usbcan_irq_write_handler(struct canchip_t *chip, struct msgobj_t *obj)
+void usbcan_kthread_read_handler(struct usbcan_usb *dev, struct usbcan_message *m,
+                               struct msgobj_t *obj)
 {
-       int cmd;
+       int i, len, retval;
+       u8 *ptr;
+
+       DEBUGMSG("USBCAN RX handler\n");
+
+       if (!test_and_clear_bit(USBCAN_MESSAGE_DATA_OK,&m->flags)) {
+               CANMSG("Strange, Rx handler USBCAN_MESSAGE_DATA_OK not set\n");
+               goto skip_msg;
+       }
+
+       if (!(dev->chip)||!(dev->chip->flags & CHIP_CONFIGURED)) {
+               CANMSG("Destination chip not found\n");
+               goto skip_msg;
+       }
+
+
+       DEBUGMSG("USBCAN Thread has received a message\n");
+
+       len=*(u8 *)(m->msg+1);
+       if(len > CAN_MSG_LENGTH) len = CAN_MSG_LENGTH;
+       obj->rx_msg.length = len;
+
+       obj->rx_msg.flags=le16_to_cpu(*(u16 *)(m->msg+2));
+       obj->rx_msg.id=le32_to_cpu((*(u32 *)(m->msg+4)));
+
+       for(ptr=m->msg+8,i=0; i < len; ptr++,i++) {
+               obj->rx_msg.data[i]=*ptr;
+       }
 
-       if(obj->tx_slot){
+       // fill CAN message timestamp
+       can_filltimestamp(&obj->rx_msg.timestamp);
+       canque_filter_msg2edges(obj->qends, &obj->rx_msg);
+
+skip_msg:
+       DEBUGMSG("Renewing RX urb\n");
+
+       usbcan_usb_message_move_list(dev, m, &dev->rx_pend_list);
+       retval = usb_submit_urb (m->u, GFP_KERNEL);
+       if (retval<0) {
+               CANMSG("URB error %d\n", retval);
+               set_bit(USBCAN_ERROR,&dev->flags);
+       }
+}
+
+/**
+ * usbcan_kthread_write_handler: - part of kthread code responsible for transmit done events
+ * @dev: pointer to usb device related structure
+ * @obj: pointer to attached message object description
+ *
+ * The main purpose of this function is to free allocated resources on transmit done event
+ * This subroutine is called by
+ * usbcan_kthread().
+ * File: src/usbcan.c
+ */
+void usbcan_kthread_write_handler(struct usbcan_usb *dev, struct usbcan_message *m,
+                               struct msgobj_t *obj)
+{
+       if (!test_and_clear_bit(USBCAN_MESSAGE_DATA_OK,&m->flags)) {
+               CANMSG("Strange, Tx handler USBCAN_MESSAGE_DATA_OK not set\n");
+               goto skip_msg;
+       }
+
+       DEBUGMSG("USBCAN Message successfully sent\n");
+
+       if(m->slot){
                // Do local transmitted message distribution if enabled
                if (processlocal){
                        // fill CAN message timestamp
-                       can_filltimestamp(&obj->tx_slot->msg.timestamp);
+                       can_filltimestamp(&m->slot->msg.timestamp);
 
-                       obj->tx_slot->msg.flags |= MSG_LOCAL;
-                       canque_filter_msg2edges(obj->qends, &obj->tx_slot->msg);
+                       m->slot->msg.flags |= MSG_LOCAL;
+                       canque_filter_msg2edges(obj->qends, &m->slot->msg);
                }
                // Free transmitted slot
-               canque_free_outslot(obj->qends, obj->tx_qedge, obj->tx_slot);
-               obj->tx_slot=NULL;
+               canque_free_outslot(obj->qends, m->qedge, m->slot);
+               m->slot=NULL;
        }
 
+       /*FIXME - why there*/
        can_msgobj_clear_fl(obj,TX_PENDING);
-       cmd=canque_test_outslot(obj->qends, &obj->tx_qedge, &obj->tx_slot);
-       if(cmd<0)
-               return;
-       can_msgobj_set_fl(obj,TX_PENDING);
 
-       if (chip->chipspecops->pre_write_config(chip, obj, &obj->tx_slot->msg)) {
-               obj->ret = -1;
-               canque_notify_inends(obj->tx_qedge, CANQUEUE_NOTIFY_ERRTX_PREP);
-               canque_free_outslot(obj->qends, obj->tx_qedge, obj->tx_slot);
-               obj->tx_slot=NULL;
+skip_msg:
+       set_bit(USBCAN_FREE_TX_URB,&dev->flags);
+
+       set_bit(USBCAN_TX_PENDING,&dev->flags);
+
+       usbcan_usb_message_move_list(dev, m, &dev->tx_idle_list);
+}
+
+/**
+ * usbcan_kthread_write_request_handler: - part of kthread code responsible for sending transmit urbs
+ * @dev: pointer to usb device related structure
+ * @obj: pointer to attached message object description
+ *
+ * The main purpose of this function is to create a usb transmit safe object
+ * and send it via free transmit usb urb
+ * This subroutine is called by
+ * usbcan_kthread().
+ * File: src/usbcan.c
+ */
+void usbcan_kthread_write_request_handler(struct usbcan_usb *dev, struct msgobj_t *obj){
+       int i, cmd, len, retval;
+       u8 *ptr;
+       struct usbcan_message *m;
+
+       if(list_empty(&dev->tx_idle_list)) {
+               clear_bit(USBCAN_FREE_TX_URB,&dev->flags);
                return;
        }
-       if (chip->chipspecops->send_msg(chip, obj, &obj->tx_slot->msg)) {
-               obj->ret = -1;
-               canque_notify_inends(obj->tx_qedge, CANQUEUE_NOTIFY_ERRTX_SEND);
-               canque_free_outslot(obj->qends, obj->tx_qedge, obj->tx_slot);
-               obj->tx_slot=NULL;
-               return;
+
+       m = list_first_entry(&dev->tx_idle_list, typeof(*m), list_node);
+
+       cmd=canque_test_outslot(obj->qends, &m->qedge, &m->slot);
+       if(cmd>=0){
+               DEBUGMSG("USBCAN Sending a message\n");
+
+               can_msgobj_set_fl(obj,TX_PENDING);
+               clear_bit(USBCAN_FREE_TX_URB,&dev->flags);
+
+               *(u8 *)(m->msg)=0;
+               len = m->slot->msg.length;
+               if(len > CAN_MSG_LENGTH)
+               len = CAN_MSG_LENGTH;
+               *(u8 *)(m->msg+1)=len & 0xFF;
+               *(u16 *)(m->msg+2)=cpu_to_le16(m->slot->msg.flags);
+               *(u32 *)(m->msg+4)=cpu_to_le32(m->slot->msg.id);
+
+               for(ptr=m->msg+8, i=0; i < len; ptr++,i++) {
+                       *ptr=m->slot->msg.data[i] & 0xFF;
+               }
+               for(; i < 8; ptr++,i++) {
+                       *ptr=0;
+               }
+
+
+               usbcan_usb_message_move_list(dev, m, &dev->tx_pend_list);
+
+               retval = usb_submit_urb (m->u, GFP_KERNEL);
+               if (retval){
+                       CANMSG("%d. URB error %d\n",i,retval);
+                       set_bit(USBCAN_FREE_TX_URB,&dev->flags);
+                       obj->ret = -1;
+                       canque_notify_inends(m->qedge, CANQUEUE_NOTIFY_ERRTX_SEND);
+                       canque_free_outslot(obj->qends, m->qedge, m->slot);
+                       m->slot=NULL;
+                       usbcan_usb_message_move_list(dev, m, &dev->tx_idle_list);
+               } else {
+                       set_bit(USBCAN_TX_PENDING,&dev->flags);
+               }
+       } else {
+               set_bit(USBCAN_FREE_TX_URB,&dev->flags);
        }
 }
 
@@ -811,95 +887,6 @@ void usbcan_irq_write_handler(struct canchip_t *chip, struct msgobj_t *obj)
  */
 int usbcan_irq_handler(int irq, struct canchip_t *chip)
 {
-/*     int irq_register, status, error_code;
-       struct msgobj_t *obj=chip->msgobj[0];
-       int loop_cnt=CHIP_MAX_IRQLOOP;
-
-       irq_register=can_read_reg(chip,SJAIR);
-//     DEBUGMSG("sja1000_irq_handler: SJAIR:%02x\n",irq_register);
-//     DEBUGMSG("sja1000_irq_handler: SJASR:%02x\n",
-//                                     can_read_reg(chip,SJASR));
-
-       if ((irq_register & (sjaIR_BEI|sjaIR_EPI|sjaIR_DOI|sjaIR_EI|sjaIR_TI|sjaIR_RI)) == 0)
-               return CANCHIP_IRQ_NONE;
-
-       if(!(chip->flags&CHIP_CONFIGURED)) {
-               CANMSG("usbcan_irq_handler: called for non-configured device, irq_register 0x%02x\n", irq_register);
-               return CANCHIP_IRQ_NONE;
-       }
-
-       status=can_read_reg(chip,SJASR);
-
-       do {
-
-               if(!loop_cnt--) {
-                       CANMSG("usbcan_irq_handler IRQ %d stuck\n",irq);
-                       return CANCHIP_IRQ_STUCK;
-               }
-
-               // (irq_register & sjaIR_TI)
-               //      old variant using SJAIR, collides with intended use with irq_accept
-               if (((status & sjaSR_TBS) && can_msgobj_test_fl(obj,TX_PENDING))||
-                   (can_msgobj_test_fl(obj,TX_REQUEST))) {
-                       DEBUGMSG("sja1000_irq_handler: TI or TX_PENDING and TBS\n");
-                       obj->ret = 0;
-                       can_msgobj_set_fl(obj,TX_REQUEST);
-                       while(!can_msgobj_test_and_set_fl(obj,TX_LOCK)){
-                               can_msgobj_clear_fl(obj,TX_REQUEST);
-
-                               if (can_read_reg(chip, SJASR) & sjaSR_TBS)
-                                       usbcan_irq_write_handler(chip, obj);
-
-                               can_msgobj_clear_fl(obj,TX_LOCK);
-                               if(!can_msgobj_test_fl(obj,TX_REQUEST)) break;
-                               DEBUGMSG("TX looping in sja1000_irq_handler\n");
-                       }
-               }
-               if ((irq_register & (sjaIR_EI|sjaIR_BEI|sjaIR_EPI|sjaIR_DOI)) != 0) {
-                       // Some error happened
-                       error_code=can_read_reg(chip,SJAECC);
-                       sja1000_report_error(chip, status, irq_register, error_code);
-// FIXME: chip should be brought to usable state. Transmission cancelled if in progress.
-// Reset flag set to 0 if chip is already off the bus. Full state report
-                       obj->ret=-1;
-
-                       if(error_code == 0xd9) {
-                               obj->ret= -ENXIO;
-                               // no such device or address - no ACK received
-                       }
-                       if(obj->tx_retry_cnt++>MAX_RETR) {
-                               can_write_reg(chip, sjaCMR_AT, SJACMR); // cancel any transmition
-                               obj->tx_retry_cnt = 0;
-                       }
-                       if(status&sjaSR_BS) {
-                               CANMSG("bus-off, resetting usbcan\n");
-                               can_write_reg(chip, 0, SJAMOD);
-                       }
-
-                       if(obj->tx_slot){
-                               canque_notify_inends(obj->tx_qedge, CANQUEUE_NOTIFY_ERRTX_BUS);
-                               //canque_free_outslot(obj->qends, obj->tx_qedge, obj->tx_slot);
-                               //obj->tx_slot=NULL;
-                       }
-
-               } else {
-                       if(sja1000_report_error_limit_counter)
-                               sja1000_report_error_limit_counter--;
-                       obj->tx_retry_cnt=0;
-               }
-
-               irq_register=can_read_reg(chip,SJAIR);
-
-               status=can_read_reg(chip,SJASR);
-
-               if(((status & sjaSR_TBS) && can_msgobj_test_fl(obj,TX_PENDING)) ||
-                  (irq_register & sjaIR_TI))
-                        can_msgobj_set_fl(obj,TX_REQUEST);
-
-       } while((irq_register & (sjaIR_BEI|sjaIR_EPI|sjaIR_DOI|sjaIR_EI|sjaIR_RI)) ||
-               (can_msgobj_test_fl(obj,TX_REQUEST) && !can_msgobj_test_fl(obj,TX_LOCK)) ||
-               (status & sjaSR_RBS));
-*/
        return CANCHIP_IRQ_HANDLED;
 }
 
@@ -916,7 +903,9 @@ int usbcan_irq_handler(int irq, struct canchip_t *chip)
  */
 int usbcan_wakeup_tx(struct canchip_t *chip, struct msgobj_t *obj)
 {
-       CANMSG("Trying to send message\n");
+       struct usbcan_usb *dev=(struct usbcan_usb *)chip->chip_data;
+
+       DEBUGMSG("Trying to send message\n");
        can_preempt_disable();
 
        can_msgobj_set_fl(obj,TX_PENDING);
@@ -924,14 +913,16 @@ int usbcan_wakeup_tx(struct canchip_t *chip, struct msgobj_t *obj)
        while(!can_msgobj_test_and_set_fl(obj,TX_LOCK)){
                can_msgobj_clear_fl(obj,TX_REQUEST);
 
-               if (!usbcan_chip_queue_status(chip)){
+               if (test_and_clear_bit(USBCAN_FREE_TX_URB,&dev->flags)){
                        obj->tx_retry_cnt=0;
-                       usbcan_irq_write_handler(chip, obj);
+                       set_bit(USBCAN_TX_PENDING,&dev->flags);
+                       if (test_bit(USBCAN_THREAD_RUNNING,&dev->flags))
+                               wake_up_process(dev->comthread);
                }
 
                can_msgobj_clear_fl(obj,TX_LOCK);
                if(!can_msgobj_test_fl(obj,TX_REQUEST)) break;
-               DEBUGMSG("TX looping in usbcan_wakeup_tx\n");
+               CANMSG("TX looping in usbcan_wakeup_tx\n");
        }
 
        can_preempt_enable();
@@ -1020,7 +1011,7 @@ int usbcan_init_chip_data(struct candevice_t *candev, int chipnr)
 
        usbcan_fill_chipspecops(chip);
 
-       candev->chip[chipnr]->flags|=CHIP_IRQ_CUSTOM;
+       candev->chip[chipnr]->flags|=CHIP_IRQ_CUSTOM|CHIP_KEEP_DATA;
        candev->chip[chipnr]->chip_base_addr=0;
        candev->chip[chipnr]->clock = 0;
 
@@ -1028,8 +1019,10 @@ int usbcan_init_chip_data(struct candevice_t *candev, int chipnr)
 }
 
 
+/** *********************************
+ *    USB related functions
+ *  ********************************* */
 
-/* --------------------------------------------------------------------------------------------------- */
 static int usbcan_sleep_thread(struct usbcan_usb *dev)
 {
        int     rc = 0;
@@ -1044,7 +1037,8 @@ static int usbcan_sleep_thread(struct usbcan_usb *dev)
                }
                if (
                        can_kthread_should_stop() ||
-                       test_bit(USBCAN_DATA_READ,&dev->flags) ||
+                       test_bit(USBCAN_DATA_OK,&dev->flags) ||
+                       test_bit(USBCAN_TX_PENDING,&dev->flags) ||
                        test_bit(USBCAN_TERMINATE,&dev->flags) ||
                        test_bit(USBCAN_ERROR,&dev->flags)
                )
@@ -1055,137 +1049,288 @@ static int usbcan_sleep_thread(struct usbcan_usb *dev)
        return rc;
 }
 
-static void usbcan_rcv(struct urb *urb)
+static void usbcan_tx_callback(struct urb *urb)
 {
-       struct usbcan_usb *dev = urb->context;
+       struct usbcan_message *m = urb->context;
        int retval;
 
-       if (!test_bit(USBCAN_THREAD_RUNNING,&dev->flags))
+       if (!test_bit(USBCAN_THREAD_RUNNING,&m->dev->flags))
+               return;
+       if (test_bit(USBCAN_MESSAGE_TERMINATE,&m->flags))
                return;
 
        switch (urb->status) {
        case 0:
                /* success */
-               set_bit(USBCAN_DATA_READ,&dev->flags);
-               CANMSG("Message received\n");
-               if (test_bit(USBCAN_THREAD_RUNNING,&dev->flags))
-                       wake_up_process(dev->comthread);
+               DEBUGMSG("%s > Message OK\n", __FUNCTION__);
+               set_bit(USBCAN_DATA_OK,&m->dev->flags);
+               set_bit(USBCAN_MESSAGE_DATA_OK,&m->flags);
+               DEBUGMSG("%s > TX flag set\n", __FUNCTION__);
+               set_bit(USBCAN_DATA_TX,&m->dev->flags);
+               usbcan_usb_message_move_list(m->dev, m, &m->dev->tx_ready_list);
+               if (test_bit(USBCAN_THREAD_RUNNING,&m->dev->flags))
+                       wake_up_process(m->dev->comthread);
+               else
+                       CANMSG("%s > USBCAN thread not running\n", __FUNCTION__);
                return;
        case -ECONNRESET:
        case -ENOENT:
        case -ESHUTDOWN:
                /* this urb is terminated, clean up */
-               CANMSG("%s - urb shutting down with status: %d\n", __FUNCTION__, urb->status);
-               set_bit(USBCAN_TERMINATE,&dev->flags);
+               CANMSG("%s > Urb shutting down with status: %d\n", __FUNCTION__, urb->status);
+//             set_bit(USBCAN_TERMINATE,&m->dev->flags);
+               set_bit(USBCAN_MESSAGE_TERMINATE,&m->flags);
                return;
        default:
-//             CANMSG("%s - nonzero urb status received: %d\n", __FUNCTION__, urb->status);
+               //CANMSG("%s > Nonzero status received: %d\n", __FUNCTION__, urb->status);
                break;
        }
 
+       // Try to send urb again on non significant errors
        retval = usb_submit_urb (urb, GFP_ATOMIC);
        if (retval<0){
-               CANMSG("%s - usb_submit_urb failed with result %d ... retrying\n",
-                    __FUNCTION__, retval);
-               set_bit(USBCAN_ERROR,&dev->flags);
-               if (test_bit(USBCAN_THREAD_RUNNING,&dev->flags))
-                       wake_up_process(dev->comthread);
+               CANMSG("%s > Retrying urb failed with result %d\n", __FUNCTION__, retval);
+               set_bit(USBCAN_ERROR,&m->dev->flags);
+               usbcan_usb_message_move_list(m->dev, m, &m->dev->tx_ready_list);
+               if (test_bit(USBCAN_THREAD_RUNNING,&m->dev->flags))
+                       wake_up_process(m->dev->comthread);
+       }
+}
+
+static void usbcan_rx_callback(struct urb *urb)
+{
+       struct usbcan_message *m = urb->context;
+       int retval;
+
+       if (!test_bit(USBCAN_THREAD_RUNNING,&m->dev->flags))    
+               return;
+       if (test_bit(USBCAN_MESSAGE_TERMINATE,&m->flags))
+               return;
+
+       switch (urb->status) {
+       case 0:
+               /* success */
+               DEBUGMSG("%s > Message OK\n", __FUNCTION__);
+               set_bit(USBCAN_DATA_OK,&m->dev->flags);
+               set_bit(USBCAN_MESSAGE_DATA_OK,&m->flags);
+               DEBUGMSG("%s > RX flag set\n", __FUNCTION__);
+               set_bit(USBCAN_DATA_RX,&m->dev->flags);
+               usbcan_usb_message_move_list(m->dev, m, &m->dev->rx_ready_list);
+               if (test_bit(USBCAN_THREAD_RUNNING,&m->dev->flags))
+                       wake_up_process(m->dev->comthread);
+               else
+                       CANMSG("%s > USBCAN thread not running\n", __FUNCTION__);
+               return;
+       case -ECONNRESET:
+       case -ENOENT:
+       case -ESHUTDOWN:
+               /* this urb is terminated, clean up */
+               CANMSG("%s > Urb shutting down with status: %d\n", __FUNCTION__, urb->status);
+//             set_bit(USBCAN_TERMINATE,&m->dev->flags);
+               set_bit(USBCAN_MESSAGE_TERMINATE,&m->flags);
+               return;
+       default:
+               //CANMSG("%s > Nonzero status received: %d\n", __FUNCTION__, urb->status);
+               break;
+       }
+
+       // Try to send urb again on non significant errors
+       retval = usb_submit_urb (urb, GFP_ATOMIC);
+       if (retval<0){
+               CANMSG("%s > Retrying urb failed with result %d\n", __FUNCTION__, retval);
+               set_bit(USBCAN_ERROR,&m->dev->flags);
+               usbcan_usb_message_move_list(m->dev, m, &m->dev->rx_ready_list);
+               if (test_bit(USBCAN_THREAD_RUNNING,&m->dev->flags))
+                       wake_up_process(m->dev->comthread);
+       }
+}
+
+
+static void usbcan_kthread_free_urbs(struct usbcan_usb *dev)
+{
+       while(!list_empty(&dev->rx_pend_list)) {
+               struct usbcan_message *m;
+               m = list_first_entry(&dev->rx_pend_list, typeof(*m), list_node);
+               set_bit(USBCAN_MESSAGE_TERMINATE,&m->flags);
+               usb_kill_urb(m->u);
+               usbcan_usb_message_move_list(dev, m, &dev->rx_ready_list);
+       }
+
+       while(!list_empty(&dev->tx_pend_list)) {
+               struct usbcan_message *m;
+               m = list_first_entry(&dev->tx_pend_list, typeof(*m), list_node);
+               set_bit(USBCAN_MESSAGE_TERMINATE,&m->flags);
+               usb_kill_urb(m->u);
+               usbcan_usb_message_move_list(dev, m, &dev->tx_idle_list);
+       }
+
+       while(!list_empty(&dev->rx_ready_list)) {
+               struct usbcan_message *m;
+               m = list_first_entry(&dev->rx_ready_list, typeof(*m), list_node);
+               list_del(&m->list_node);
+               usb_free_urb(m->u);
+               kfree(m);
        }
+
+       while(!list_empty(&dev->tx_ready_list)) {
+               struct usbcan_message *m;
+               m = list_first_entry(&dev->tx_ready_list, typeof(*m), list_node);
+               list_del(&m->list_node);
+               usb_free_urb(m->u);
+               kfree(m);
+       }
+
+       while(!list_empty(&dev->tx_idle_list)) {
+               struct usbcan_message *m;
+               m = list_first_entry(&dev->tx_idle_list, typeof(*m), list_node);
+               list_del(&m->list_node);
+               usb_free_urb(m->u);
+               kfree(m);
+       }
+
 }
 
-int usbcan_read_kthread(void *data)
+int usbcan_kthread(void *data)
 {
-       int retval=0;
+       int i,retval=0;
        struct usbcan_usb *dev=(struct usbcan_usb *)data;
        struct msgobj_t *obj;
 
-  /* this is normal work to do */
-  CANMSG ("usbcan thread started!\n");
+       CANMSG("Usbcan thread started...\n");
 
-       dev->rx = usb_alloc_urb(0, GFP_KERNEL);
-       if (!dev->rx){
-               CANMSG("Error allocating usb urb\n");
+       if (!dev->chip)
                goto error;
+       obj=dev->chip->msgobj[0];
+
+       INIT_LIST_HEAD(&dev->rx_pend_list);
+       INIT_LIST_HEAD(&dev->rx_ready_list);
+       INIT_LIST_HEAD(&dev->tx_idle_list);
+       INIT_LIST_HEAD(&dev->tx_pend_list);
+       INIT_LIST_HEAD(&dev->tx_ready_list);
+
+       if (1) {
+               struct sched_param param = { .sched_priority = 1 };
+               sched_setscheduler(current, SCHED_FIFO, &param);
+       }
+
+
+       /* Prepare receive urbs  */
+       for (i=0;i<USBCAN_TOT_RX_URBS;i++){
+               struct usbcan_message *m;
+               struct urb *u = usb_alloc_urb(0, GFP_KERNEL);
+               if (!u){
+                       CANMSG("Error allocating %d. usb receive urb\n",i);
+                       goto error;
+               }
+               m = kzalloc(sizeof(struct usbcan_message), GFP_KERNEL);
+               if(!m) {
+                       usb_free_urb(u);
+                       CANMSG("Error allocating %d. receive usbcan_message\n",i);
+                       goto error;
+               }
+               m->u = u;
+               u->dev = dev->udev;
+               m->dev = dev;
+               usb_fill_bulk_urb(u, dev->udev,
+                       usb_rcvbulkpipe(dev->udev, dev->bulk_in_endpointAddr),
+                       m->msg, USBCAN_TRANSFER_SIZE, usbcan_rx_callback, m);
+
+               list_add_tail(&m->list_node, &dev->rx_ready_list);
+       }
+
+       /* Prepare transmit urbs  */
+       for (i=0;i<USBCAN_TOT_TX_URBS;i++){
+               struct usbcan_message *m;
+               struct urb *u = usb_alloc_urb(0, GFP_KERNEL);
+               if (!u){
+                       CANMSG("Error allocating %d. usb transmit urb\n",i);
+                       goto error;
+               }
+               m = kzalloc(sizeof(struct usbcan_message), GFP_KERNEL);
+               if(!m) {
+                       usb_free_urb(u);
+                       CANMSG("Error allocating %d. transmit usbcan_message\n",i);
+                       goto error;
+               }
+               m->u = u;
+               u->dev = dev->udev;
+               m->dev = dev;
+               usb_fill_bulk_urb(u, dev->udev,
+                       usb_sndbulkpipe(dev->udev, dev->bulk_out_endpointAddr),
+                       m->msg, USBCAN_TRANSFER_SIZE, usbcan_tx_callback, m);
+
+               list_add_tail(&m->list_node, &dev->tx_idle_list);
+
        }
-       dev->rx->dev = dev->udev;
-       usb_fill_bulk_urb(dev->rx, dev->udev,
-                        usb_rcvbulkpipe(dev->udev, dev->bulk_in_endpointAddr),
-                        &dev->rx_msg, 16,
-                        usbcan_rcv, dev);
 
        set_bit(USBCAN_THREAD_RUNNING,&dev->flags);
-  /* an endless loop in which we are doing our work */
-  for(;;)
-  {
-               retval=usb_submit_urb(dev->rx, GFP_ATOMIC);
+       set_bit(USBCAN_FREE_TX_URB,&dev->flags);
+
+       for (i=0;i<USBCAN_TOT_RX_URBS;i++){
+               struct usbcan_message *m;
+               m = list_first_entry(&dev->rx_ready_list, typeof(*m), list_node);
+               usbcan_usb_message_move_list(dev, m, &dev->rx_pend_list);
+
+               retval=usb_submit_urb(m->u, GFP_KERNEL);
                if (retval){
-                       CANMSG("URB error %d\n",retval);
+                       CANMSG("%d. URB error %d\n",i,retval);
                        set_bit(USBCAN_ERROR,&dev->flags);
-                       break;
+                       usbcan_usb_message_move_list(dev, m, &dev->rx_ready_list);
+                       goto exit;
                }
+       }
+       /* an endless loop in which we are doing our work */
+       for(;;)
+       {
                /* We need to do a memory barrier here to be sure that
                the flags are visible on all CPUs. */
                mb();
                /* fall asleep */
-               usbcan_sleep_thread(dev);
-               /* We need to do a memory barrier here to be sure that
-               the flags are visible on all CPUs. */
+               if (!can_kthread_should_stop() && !test_bit(USBCAN_TERMINATE,&dev->flags) && (usbcan_sleep_thread(dev)<0)){
+                       break;
+               }
+               /* We need to do a memory barrier here to be sure that the flags are visible on all CPUs. */
                mb();
 
-               /* here we are back from sleep because we caught a signal. */
-               if (can_kthread_should_stop())
-               {
-                       /* we received a request to terminate ourself */
+               if (can_kthread_should_stop() || test_bit(USBCAN_TERMINATE,&dev->flags)){
                        break;
                }
 
-               { /* Normal work to do */
-                       if (test_bit(USBCAN_DATA_READ,&dev->flags)){
-                               int i, len;
-                               clear_bit(USBCAN_DATA_READ,&dev->flags);
-                               CANMSG("Thread got received message\n");
+               clear_bit(USBCAN_DATA_OK,&dev->flags);
 
-                               if ((dev->chip)&&
-                                       (dev->chip->flags & CHIP_CONFIGURED)
-                               ){
-                                       u8 *ptr;
+               mb();
 
-                                       obj=dev->chip->msgobj[0];
+               while(!list_empty(&dev->rx_ready_list)) {
+                       struct usbcan_message *m;
+                       m = list_first_entry(&dev->rx_ready_list, typeof(*m), list_node);
+                       usbcan_kthread_read_handler(dev, m, obj);
+               }
 
-                                       len=*(uint8_t *)(dev->rx_msg+1);
-                                       if(len > CAN_MSG_LENGTH) len = CAN_MSG_LENGTH;
-                                       obj->rx_msg.length = len;
+               while(!list_empty(&dev->tx_ready_list)) {
+                       struct usbcan_message *m;
+                       m = list_first_entry(&dev->tx_ready_list, typeof(*m), list_node);
+                       usbcan_kthread_write_handler(dev, m, obj);
+               }
 
-                                       obj->rx_msg.flags=le16_to_cpu(*(uint16_t *)(dev->rx_msg+2));
-                                       obj->rx_msg.id=le32_to_cpu((*(uint32_t *)(dev->rx_msg+4)));
+               if (test_and_clear_bit(USBCAN_TX_PENDING,&dev->flags)) {
+                       usbcan_kthread_write_request_handler(dev, obj);
+               }
+       }
 
-                                       for(ptr=dev->rx_msg+8,i=0; i < len; ptr++,i++) {
-                                               obj->rx_msg.data[i]=*ptr;
-                                       }
+       set_bit(USBCAN_TERMINATE,&dev->flags);
+exit:
 
-                                       // fill CAN message timestamp
-                                       can_filltimestamp(&obj->rx_msg.timestamp);
-                                       canque_filter_msg2edges(obj->qends, &obj->rx_msg);
-                               }
-                               else
-                                       CANMSG("Destination chip not found\n");
-                       }
-    }
-  }
+       usbcan_kthread_free_urbs(dev);
        clear_bit(USBCAN_THREAD_RUNNING,&dev->flags);
 
-  /* here we go only in case of termination of the thread */
-       if (dev->rx){
-               usb_kill_urb(dev->rx);
-               usb_free_urb(dev->rx);
-       }
-
-  CANMSG ("usbcan thread finished!\n");
-  return 0;
+       CANMSG ("usbcan thread finished!\n");
+       return 0;
 error:
-  /* cleanup the thread, leave */
-  CANMSG ("kernel thread terminated!\n");
-  return -ENOMEM;
+       /* cleanup the thread, leave */
+       usbcan_kthread_free_urbs(dev);
+
+       CANMSG ("kernel thread terminated!\n");
+       return -ENOMEM;
 }
 
 static int usbcan_probe(struct usb_interface *interface, const struct usb_device_id *id)
@@ -1199,7 +1344,7 @@ static int usbcan_probe(struct usb_interface *interface, const struct usb_device
 
        iface_desc = interface->cur_altsetting;
        if (iface_desc->desc.bNumEndpoints % 2){
-               err("Endpoint count must be even");
+               CANMSG("Endpoint count must be even");
                goto noalloc;
        }
 
@@ -1207,16 +1352,15 @@ static int usbcan_probe(struct usb_interface *interface, const struct usb_device
 
        usbdevs = (struct usbcan_devs *) can_checked_malloc(sizeof(struct usbcan_devs));
        if (!usbdevs) {
-               err("Out of memory");
-               goto error;
+               goto noalloc;
        }
        memset(usbdevs, 0, sizeof(struct usbcan_devs));
 
-       usbdevs->count=usbcan_chip_count;
+       usbdevs->count = usbcan_chip_count;
+       usbdevs->udev = interface_to_usbdev(interface);
 
        usbdevs->devs = (struct usbcan_usb **) can_checked_malloc(usbcan_chip_count * sizeof(struct usbcan_usb *));
        if (!usbdevs->devs) {
-               err("Out of memory");
                goto error;
        }
        memset(usbdevs->devs, 0, usbcan_chip_count * sizeof(struct usbcan_usb *));
@@ -1228,14 +1372,15 @@ static int usbcan_probe(struct usb_interface *interface, const struct usb_device
                /* allocate memory for our device state and initialize it */
                usbdevs->devs[j] = (struct usbcan_usb *) can_checked_malloc(sizeof(struct usbcan_usb));
                if (!usbdevs->devs[j]) {
-                       err("Out of memory");
                        goto error;
                }
                memset(usbdevs->devs[j], 0, sizeof(struct usbcan_usb));
                dev=usbdevs->devs[j];
+               spin_lock_init(&dev->list_lock);
 
                mutex_init(&dev->io_mutex);
-               dev->udev = interface_to_usbdev(interface);
+               init_waitqueue_head(&dev->queue);
+               dev->udev = usbdevs->udev;
                dev->interface = interface;
 
                /* set up the endpoint information */
@@ -1261,7 +1406,7 @@ static int usbcan_probe(struct usb_interface *interface, const struct usb_device
                                        dev->bulk_in_endpointAddr = endpoint->bEndpointAddress;
                                        dev->bulk_in_buffer = can_checked_malloc(buffer_size);
                                        if (!dev->bulk_in_buffer) {
-                                               err("Could not allocate bulk_in_buffer");
+                                               CANMSG("Could not allocate bulk_in_buffer");
                                                goto error;
                                        }
                                }
@@ -1277,28 +1422,32 @@ static int usbcan_probe(struct usb_interface *interface, const struct usb_device
 
                }
                if (!(dev->bulk_in_endpointAddr && dev->bulk_out_endpointAddr)) {
-                       err("Could not find all bulk-in and bulk-out endpoints for chip %d",j);
+                       CANMSG("Could not find all bulk-in and bulk-out endpoints for chip %d",j);
                        goto error;
                }
        }
+
+       usb_get_dev(usbdevs->udev);
+
        /* save our data pointer in this interface device */
        usb_set_intfdata(interface, usbdevs);
 
-       if (!(usbdevs->candev=register_usbdev("usbcan",(void *) usbdevs, usbcan_register_devs)))
+       usbdevs->candev=register_hotplug_dev("usbcan", usbcan_register_devs,(void *) usbdevs);
+       if (!(usbdevs->candev)){
+               CANMSG("register_hotplug_dev() failed\n");
                goto register_error;
+       }
 
        /* let the user know what node this device is now attached to */
-       DEBUGMSG("USBCAN device now attached");
+       CANMSG("USBCAN device now attached\n");
        return 0;
 
 register_error:
-       cleanup_usbdev(usbdevs->candev);
+//     cleanup_hotplug_dev(usbdevs->candev);
+       usb_put_dev(usbdevs->udev);
 error:
        if (usbdevs){
                if (usbdevs->devs){
-                       if (usbdevs->devs[0]){
-                               usb_put_dev(usbdevs->devs[0]->udev);
-                       }
                        for (j=0;j<usbdevs->count;j++){
                                if (!usbdevs->devs[j])  continue;
 
@@ -1317,36 +1466,31 @@ noalloc:
        return retval;
 }
 
-// Physically disconnected device
-static void usbcan_disconnect(struct usb_interface *interface)
-{
-       struct usbcan_devs *usbdevs;
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,10))
+void release_device(struct kref *refcount){
+       struct candevice_t *candev = container_of(refcount,struct candevice_t,refcount);
+#else
+void release_device(struct candevice_t *candev){
+#endif
+       struct usbcan_devs *usbdevs = (struct usbcan_devs *)candev->sysdevptr.anydev;
        int j;
-       usbdevs = usb_get_intfdata(interface);
-       if (usbdevs==NULL){
-               CANMSG("USBCAN device seems to be removed\n");
+
+       if (!usbdevs)
                return;
-       }
-       usb_set_intfdata(interface, NULL);
+
+       cleanup_hotplug_dev(usbdevs->candev);
 
        if (usbdevs->devs){
-               usb_put_dev((*usbdevs->devs)->udev);
-       }
-       cleanup_usbdev(usbdevs->candev);
-       if (usbdevs->devs){
+               /* Finally, release all structures in USB subsystem */
+               if (!usbdevs->udev)
+                       panic("udev is already null on device release");
+               usb_put_dev(usbdevs->udev);
+
                for (j=0;j<usbdevs->count;j++){
                        if (!usbdevs->devs[j])  continue;
 
-                       /* prevent more I/O from starting */
-                       mutex_lock(&usbdevs->devs[j]->io_mutex);
-                       usbdevs->devs[j]->interface = NULL;
-                       mutex_unlock(&usbdevs->devs[j]->io_mutex);
-
                        if (usbdevs->devs[j]->bulk_in_buffer)
                                can_checked_free(usbdevs->devs[j]->bulk_in_buffer);
-                       // if (usbdevs->devs[j]->chip){
-                       //      usbdevs->devs[j]->chip->chip_data=NULL;
-                       // }
                        can_checked_free(usbdevs->devs[j]);
                        usbdevs->devs[j]=NULL;
                }
@@ -1354,7 +1498,41 @@ static void usbcan_disconnect(struct usb_interface *interface)
        }
        can_checked_free(usbdevs);
 
-       DEBUGMSG("USBCAN now disconnected");
+       CANMSG("USBCAN now disconnected\n");
+}
+
+// Physically disconnected device
+static void usbcan_disconnect(struct usb_interface *interface)
+{
+       struct usbcan_devs *usbdevs;
+       int j;
+
+       /* prevent more I/O from starting */
+       lock_kernel();
+
+       usbdevs = usb_get_intfdata(interface);
+       if (usbdevs==NULL){
+               CANMSG("USBCAN device seems to be already removed\n");
+               unlock_kernel();
+               return;
+       }
+       usb_set_intfdata(interface, NULL);
+       deregister_hotplug_dev(usbdevs->candev);
+
+       for (j=0;j<usbdevs->count;j++){
+               if (!usbdevs->devs[j])  continue;
+               mutex_lock(&usbdevs->devs[j]->io_mutex);
+               usbdevs->devs[j]->interface = NULL;
+               mutex_unlock(&usbdevs->devs[j]->io_mutex);
+       }
+
+       unlock_kernel();
+
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,10))
+       kref_put(&usbdevs->candev->refcount,release_device);
+#else
+       release_device(&usbdevs->candev);
+#endif
 }
 
 int usbcan_init(void){