diff options
Diffstat (limited to 'nuttx/drivers/can.c')
| -rw-r--r-- | nuttx/drivers/can.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/nuttx/drivers/can.c b/nuttx/drivers/can.c index accafce3c..fc70678a7 100644 --- a/nuttx/drivers/can.c +++ b/nuttx/drivers/can.c @@ -50,6 +50,7 @@ #include <string.h> #include <semaphore.h> #include <fcntl.h> +#include <assert.h> #include <errno.h> #include <debug.h> @@ -443,7 +444,11 @@ static ssize_t can_write(FAR struct file *filep, FAR const char *buffer, size_t do { + DEBUGASSERT(dev->cd_ntxwaiters < 255); + dev->cd_ntxwaiters++; ret = sem_wait(&fifo->cf_sem); + dev->cd_ntxwaiters--; + if (ret < 0 && errno != EINTR) { ret = -errno; @@ -750,9 +755,12 @@ int can_txdone(FAR struct can_dev_s *dev) /* Send the next message in the FIFO */ ret = can_xmit(dev); - if (ret == OK) + + /* Are there any threads waiting for space in the TX FIFO? */ + + if (ret == OK && dev->cd_ntxwaiters > 0) { - /* Inform any waiting threads that new xmit space is available */ + /* Yes.. Inform them that new xmit space is available */ ret = sem_post(&dev->cd_xmit.cf_sem); } |