diff options
| -rw-r--r-- | drivers/staging/axis-fifo/axis-fifo.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/drivers/staging/axis-fifo/axis-fifo.c b/drivers/staging/axis-fifo/axis-fifo.c index 57ed58065eba..8d5bbe81b499 100644 --- a/drivers/staging/axis-fifo/axis-fifo.c +++ b/drivers/staging/axis-fifo/axis-fifo.c @@ -322,11 +322,17 @@ static ssize_t axis_fifo_write(struct file *f, const char __user *buf, return -EINVAL; } - if (words_to_write > fifo->tx_fifo_depth) { - dev_err(fifo->dt_device, "tried to write more words [%u] than slots in the fifo buffer [%u]\n", - words_to_write, fifo->tx_fifo_depth); + /* + * In 'Store-and-Forward' mode, the maximum packet that can be + * transmitted is limited by the size of the FIFO, which is + * (C_TX_FIFO_DEPTH–4)*(data interface width/8) bytes. + * + * Do not attempt to send a packet larger than 'tx_fifo_depth - 4', + * otherwise a 'Transmit Packet Overrun Error' interrupt will be + * raised, which requires a reset of the TX circuit to recover. + */ + if (words_to_write > (fifo->tx_fifo_depth - 4)) return -EINVAL; - } if (fifo->write_flags & O_NONBLOCK) { /* |