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Fix LPC17 CAN driver; TX must be interrupt driven

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git-svn-id: https://nuttx.svn.sourceforge.net/svnroot/nuttx/trunk@4290 7fd9a85b-ad96-42d3-883c-3090e2eb8679
This commit is contained in:
patacongo
2012-01-10 22:29:39 +00:00
parent 6cd77c1702
commit 1e16645fb4
4 changed files with 116 additions and 45 deletions
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nuttx/drivers/can.c
+15 -11
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@@ -375,9 +375,11 @@ static int can_xmit(FAR struct can_dev_s *dev)
canllvdbg("xmit head: %d tail: %d\n", dev->cd_xmit.cf_head, dev->cd_xmit.cf_tail);
/* Check if the xmit FIFO is empty */
/* Check if the xmit FIFO is not empty and the CAN hardware is ready to accept
* more data.
*/
if (dev->cd_xmit.cf_head != dev->cd_xmit.cf_tail)
if (dev->cd_xmit.cf_head != dev->cd_xmit.cf_tail && dev_txready(dev))
{
/* Send the next message at the head of the FIFO */
@@ -401,7 +403,7 @@ static ssize_t can_write(FAR struct file *filep, FAR const char *buffer, size_t
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 empty = false;
bool inactive;
ssize_t nsent = 0;
irqstate_t flags;
int nexttail;
@@ -414,11 +416,12 @@ static ssize_t can_write(FAR struct file *filep, FAR const char *buffer, size_t
flags = irqsave();
/* Check if the TX FIFO was empty when we started. That is a clue that we have
* to kick off a new TX sequence.
/* Check if the TX is inactive when we started. In certain race conditionas, there
* may be a pending interrupt to kick things back off, but we will here that there
* is not. That the hardware is IDLE and will need to be kick-started.
*/
empty = (fifo->cf_head == fifo->cf_tail);
inactive = dev_txempty(dev);
/* Add the messages to the FIFO. Ignore any trailing messages that are
* shorter than the minimum.
@@ -455,11 +458,12 @@ static ssize_t can_write(FAR struct file *filep, FAR const char *buffer, size_t
goto return_with_irqdisabled;
}
/* If the FIFO was empty when we started, then we will have
* start the XMIT sequence to clear the FIFO.
/* If the TX hardware was inactive when we started, then we will have
* start the XMIT sequence generate the TX done interrrupts needed
* to clear the FIFO.
*/
if (empty)
if (inactive)
{
can_xmit(dev);
}
@@ -483,7 +487,7 @@ static ssize_t can_write(FAR struct file *filep, FAR const char *buffer, size_t
/* Re-check the FIFO state */
empty = (fifo->cf_head == fifo->cf_tail);
inactive = dev_txempty(dev);
}
/* We get here if there is space at the end of the FIFO. Add the new
@@ -507,7 +511,7 @@ static ssize_t can_write(FAR struct file *filep, FAR const char *buffer, size_t
* we need to kick of the XMIT sequence.
*/
if (empty)
if (inactive)
{
can_xmit(dev);
}