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author | patacongo <patacongo@42af7a65-404d-4744-a932-0658087f49c3> | 2012-01-11 05:03:51 +0000 |
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committer | patacongo <patacongo@42af7a65-404d-4744-a932-0658087f49c3> | 2012-01-11 05:03:51 +0000 |
commit | 297039ce52f88f041ad2111bc04ec5559ac185af (patch) | |
tree | 158a05d5cc83449c29199620e872f4f6a4a2b9ab /nuttx/drivers/can.c | |
parent | dadcb8540ae070f09279d9dcebb7ed7b3ce55a6f (diff) | |
download | px4-nuttx-297039ce52f88f041ad2111bc04ec5559ac185af.tar.gz px4-nuttx-297039ce52f88f041ad2111bc04ec5559ac185af.tar.bz2 px4-nuttx-297039ce52f88f041ad2111bc04ec5559ac185af.zip |
Fix last change; the change was good but will prevent queuing multiple outgoing CAN packets
git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@4293 42af7a65-404d-4744-a932-0658087f49c3
Diffstat (limited to 'nuttx/drivers/can.c')
-rw-r--r-- | nuttx/drivers/can.c | 150 |
1 files changed, 95 insertions, 55 deletions
diff --git a/nuttx/drivers/can.c b/nuttx/drivers/can.c index 6928fbd1f..ec61fef17 100644 --- a/nuttx/drivers/can.c +++ b/nuttx/drivers/can.c @@ -169,10 +169,11 @@ static int can_open(FAR struct file *filep) { /* Mark the FIFOs empty */ - dev->cd_xmit.cf_head = 0; - dev->cd_xmit.cf_tail = 0; - dev->cd_recv.cf_head = 0; - dev->cd_recv.cf_tail = 0; + dev->cd_xmit.tx_head = 0; + dev->cd_xmit.tx_queue = 0; + dev->cd_xmit.tx_tail = 0; + dev->cd_recv.rx_head = 0; + dev->cd_recv.rx_tail = 0; /* Finally, Enable the CAN RX interrupt */ @@ -235,7 +236,7 @@ static int can_close(FAR struct file *filep) /* Now we wait for the transmit FIFO to clear */ - while (dev->cd_xmit.cf_head != dev->cd_xmit.cf_tail) + while (dev->cd_xmit.tx_head != dev->cd_xmit.tx_tail) { #ifndef CONFIG_DISABLE_SIGNALS usleep(HALF_SECOND_USEC); @@ -294,7 +295,7 @@ static ssize_t can_read(FAR struct file *filep, FAR char *buffer, size_t buflen) /* Interrupts must be disabled while accessing the cd_recv FIFO */ flags = irqsave(); - while (dev->cd_recv.cf_head == dev->cd_recv.cf_tail) + while (dev->cd_recv.rx_head == dev->cd_recv.rx_tail) { /* The receive FIFO is empty -- was non-blocking mode selected? */ @@ -306,7 +307,7 @@ static ssize_t can_read(FAR struct file *filep, FAR char *buffer, size_t buflen) /* Wait for a message to be received */ - ret = sem_wait(&dev->cd_recv.cf_sem); + ret = sem_wait(&dev->cd_recv.rx_sem); if (ret < 0) { ret = -errno; @@ -323,7 +324,7 @@ static ssize_t can_read(FAR struct file *filep, FAR char *buffer, size_t buflen) { /* Will the next message in the FIFO fit into the user buffer? */ - FAR struct can_msg_s *msg = &dev->cd_recv.cf_buffer[dev->cd_recv.cf_head]; + FAR struct can_msg_s *msg = &dev->cd_recv.rx_buffer[dev->cd_recv.rx_head]; int msglen = CAN_MSGLEN(msg->cm_hdr); if (nread + msglen > buflen) @@ -338,12 +339,12 @@ static ssize_t can_read(FAR struct file *filep, FAR char *buffer, size_t buflen) /* Increment the head of the circular message buffer */ - if (++dev->cd_recv.cf_head >= CONFIG_CAN_FIFOSIZE) + if (++dev->cd_recv.rx_head >= CONFIG_CAN_FIFOSIZE) { - dev->cd_recv.cf_head = 0; + dev->cd_recv.rx_head = 0; } } - while (dev->cd_recv.cf_head != dev->cd_recv.cf_tail); + while (dev->cd_recv.rx_head != dev->cd_recv.rx_tail); /* All on the messages have bee transferred. Return the number of bytes * that were read. @@ -370,26 +371,62 @@ return_with_irqdisabled: static int can_xmit(FAR struct can_dev_s *dev) { - bool enable = false; - int ret = OK; + int tmpndx; + int ret = -EBUSY; - canllvdbg("xmit head: %d tail: %d\n", dev->cd_xmit.cf_head, dev->cd_xmit.cf_tail); + canllvdbg("xmit head: %d queue: %d tail: %d\n", + dev->cd_xmit.tx_head, dev->cd_xmit.tx_queue, dev->cd_xmit.tx_tail); - /* Check if the xmit FIFO is not empty and the CAN hardware is ready to accept - * more data. + /* If there is nothing to send, then just disable interrupts and return */ + + if (dev->cd_xmit.tx_head == dev->cd_xmit.tx_tail) + { + DEBUGASSERT(dev->cd_xmit.tx_queue == dev->cd_xmit.tx_head); + dev_txint(dev, false); + return -EIO; + } + + /* Check if we have already queued all of the data in the TX fifo. + * + * tx_tail: Incremented in can_write each time a message is queued in the FIFO + * tx_head: Incremented in can_txdone each time a message completes + * tx_queue: Incremented each time that a message is sent to the hardware. + * + * Logically (ignoring buffer wrap-around): tx_head <= tx_queue <= tx_tail + * tx_head == tx_queue == tx_tail means that the FIFO is empty + * tx_head < tx_queue == tx_tail means that all data has been queued, but + * we are still waiting for transmissions to complete. */ - if (dev->cd_xmit.cf_head != dev->cd_xmit.cf_tail && dev_txready(dev)) + while (dev->cd_xmit.tx_queue != dev->cd_xmit.tx_tail && dev_txready(dev)) { - /* Send the next message at the head of the FIFO */ + /* No.. The fifo should not be empty in this case */ - ret = dev_send(dev, &dev->cd_xmit.cf_buffer[dev->cd_xmit.cf_head]); + DEBUGASSERT(dev->cd_xmit.tx_head != dev->cd_xmit.tx_tail); - /* Make sure the TX done interrupts are enabled */ + /* Increment the FIFO queue index before sending (because dev_send() + * might call can_txdone(). + */ + + tmpndx = dev->cd_xmit.tx_queue; + if (++dev->cd_xmit.tx_queue >= CONFIG_CAN_FIFOSIZE) + { + dev->cd_xmit.tx_queue = 0; + } - enable = (ret == OK ? true : false); + /* Send the next message at the FIFO queue index */ + + ret = dev_send(dev, &dev->cd_xmit.tx_buffer[tmpndx]); + if (ret != OK) + { + candbg("dev_send failed: %d\n", ret); + break; + } } - dev_txint(dev, enable); + + /* Make sure that TX interrupts are enabled */ + + dev_txint(dev, true); return ret; } @@ -399,16 +436,16 @@ static int can_xmit(FAR struct can_dev_s *dev) static ssize_t can_write(FAR struct file *filep, FAR const char *buffer, size_t buflen) { - FAR struct inode *inode = filep->f_inode; - FAR struct can_dev_s *dev = inode->i_private; - FAR struct can_fifo_s *fifo = &dev->cd_xmit; - FAR struct can_msg_s *msg; - bool inactive; - ssize_t nsent = 0; - irqstate_t flags; - int nexttail; - int msglen; - int ret = 0; + FAR struct inode *inode = filep->f_inode; + FAR struct can_dev_s *dev = inode->i_private; + FAR struct can_txfifo_s *fifo = &dev->cd_xmit; + FAR struct can_msg_s *msg; + bool inactive; + ssize_t nsent = 0; + irqstate_t flags; + int nexttail; + int msglen; + int ret = 0; canvdbg("buflen: %d\n", buflen); @@ -433,7 +470,7 @@ static ssize_t can_write(FAR struct file *filep, FAR const char *buffer, size_t * xmit data. */ - nexttail = fifo->cf_tail + 1; + nexttail = fifo->tx_tail + 1; if (nexttail >= CONFIG_CAN_FIFOSIZE) { nexttail = 0; @@ -441,7 +478,7 @@ static ssize_t can_write(FAR struct file *filep, FAR const char *buffer, size_t /* If the XMIT fifo becomes full, then wait for space to become available */ - while (nexttail == fifo->cf_head) + while (nexttail == fifo->tx_head) { /* The transmit FIFO is full -- was non-blocking mode selected? */ @@ -474,7 +511,7 @@ static ssize_t can_write(FAR struct file *filep, FAR const char *buffer, size_t { DEBUGASSERT(dev->cd_ntxwaiters < 255); dev->cd_ntxwaiters++; - ret = sem_wait(&fifo->cf_sem); + ret = sem_wait(&fifo->tx_sem); dev->cd_ntxwaiters--; if (ret < 0 && errno != EINTR) @@ -496,11 +533,11 @@ static ssize_t can_write(FAR struct file *filep, FAR const char *buffer, size_t msg = (FAR struct can_msg_s *)&buffer[nsent]; msglen = CAN_MSGLEN(msg->cm_hdr); - memcpy(&fifo->cf_buffer[fifo->cf_tail], msg, msglen); + memcpy(&fifo->tx_buffer[fifo->tx_tail], msg, msglen); /* Increment the tail of the circular buffer */ - fifo->cf_tail = nexttail; + fifo->tx_tail = nexttail; /* Increment the number of bytes that were sent */ @@ -632,8 +669,8 @@ int can_register(FAR const char *path, FAR struct can_dev_s *dev) dev->cd_ocount = 0; - sem_init(&dev->cd_xmit.cf_sem, 0, 0); - sem_init(&dev->cd_recv.cf_sem, 0, 0); + sem_init(&dev->cd_xmit.tx_sem, 0, 0); + sem_init(&dev->cd_recv.rx_sem, 0, 0); sem_init(&dev->cd_closesem, 0, 1); for (i = 0; i < CONFIG_CAN_NPENDINGRTR; i++) @@ -671,11 +708,11 @@ int can_register(FAR const char *path, FAR struct can_dev_s *dev) int can_receive(FAR struct can_dev_s *dev, uint16_t hdr, FAR uint8_t *data) { - FAR struct can_fifo_s *fifo = &dev->cd_recv; - FAR uint8_t *dest; - int nexttail; - int err = -ENOMEM; - int i; + FAR struct can_rxfifo_s *fifo = &dev->cd_recv; + FAR uint8_t *dest; + int nexttail; + int err = -ENOMEM; + int i; canllvdbg("ID: %d DLC: %d\n", CAN_ID(hdr), CAN_DLC(hdr)); @@ -683,7 +720,7 @@ int can_receive(FAR struct can_dev_s *dev, uint16_t hdr, FAR uint8_t *data) * read data. */ - nexttail = fifo->cf_tail + 1; + nexttail = fifo->rx_tail + 1; if (nexttail >= CONFIG_CAN_FIFOSIZE) { nexttail = 0; @@ -729,25 +766,25 @@ int can_receive(FAR struct can_dev_s *dev, uint16_t hdr, FAR uint8_t *data) /* Refuse the new data if the FIFO is full */ - if (nexttail != fifo->cf_head) + if (nexttail != fifo->rx_head) { /* Add the new, decoded CAN message at the tail of the FIFO */ - fifo->cf_buffer[fifo->cf_tail].cm_hdr = hdr; - for (i = 0, dest = fifo->cf_buffer[fifo->cf_tail].cm_data; i < CAN_DLC(hdr); i++) + fifo->rx_buffer[fifo->rx_tail].cm_hdr = hdr; + for (i = 0, dest = fifo->rx_buffer[fifo->rx_tail].cm_data; i < CAN_DLC(hdr); i++) { *dest++ = *data++; } /* Increment the tail of the circular buffer */ - fifo->cf_tail = nexttail; + fifo->rx_tail = nexttail; /* The increment the counting semaphore. The maximum value should be * CONFIG_CAN_FIFOSIZE -- one possible count for each allocated message buffer. */ - sem_post(&fifo->cf_sem); + sem_post(&fifo->rx_sem); err = OK; } return err; @@ -773,17 +810,20 @@ int can_txdone(FAR struct can_dev_s *dev) { int ret = -ENOENT; - canllvdbg("xmit head: %d tail: %d\n", dev->cd_xmit.cf_head, dev->cd_xmit.cf_tail); + canllvdbg("xmit head: %d queue: %d tail: %d\n", + dev->cd_xmit.tx_head, dev->cd_xmit.tx_queue, dev->cd_xmit.tx_tail); /* Verify that the xmit FIFO is not empty */ - if (dev->cd_xmit.cf_head != dev->cd_xmit.cf_tail) + if (dev->cd_xmit.tx_head != dev->cd_xmit.tx_tail) { + DEBUGASSERT(dev->cd_xmit.tx_head != dev->cd_xmit.tx_queue); + /* Remove the message at the head of the xmit FIFO */ - if (++dev->cd_xmit.cf_head >= CONFIG_CAN_FIFOSIZE) + if (++dev->cd_xmit.tx_head >= CONFIG_CAN_FIFOSIZE) { - dev->cd_xmit.cf_head = 0; + dev->cd_xmit.tx_head = 0; } /* Send the next message in the FIFO */ @@ -796,7 +836,7 @@ int can_txdone(FAR struct can_dev_s *dev) { /* Yes.. Inform them that new xmit space is available */ - ret = sem_post(&dev->cd_xmit.cf_sem); + ret = sem_post(&dev->cd_xmit.tx_sem); } } return ret; |