/* Per-channel lock */
spinlock_t lock;
- /* Stop the channel on hardware failure.
+ /* Stop the channel on UART side hardware failure, e.g. stray
+ * characters or neverending lines. This may be caused by bad
+ * UART wiring, a bad ELM327, a bad UART bridge...
* Once this is true, nothing will be sent to the TTY.
*/
- bool hw_failure;
+ bool uart_side_failure;
/* TTY TX helpers */
struct work_struct tx_work; /* Flushes TTY TX buffer */
unsigned long cmds_todo;
};
-static inline void elm327_hw_failure(struct elmcan *elm);
+static inline void elm327_uart_side_failure(struct elmcan *elm);
static void elm327_send(struct elmcan *elm, const void *buf, size_t len)
{
lockdep_assert_held(elm->lock);
- if (elm->hw_failure)
+ if (elm->uart_side_failure)
return;
memcpy(elm->txbuf, buf, len);
netdev_err(elm->dev,
"Failed to write to tty %s.\n",
elm->tty->name);
- elm327_hw_failure(elm);
+ elm327_uart_side_failure(elm);
return;
}
}
/* Called when we're out of ideas and just want it all to end. */
-static inline void elm327_hw_failure(struct elmcan *elm)
+static inline void elm327_uart_side_failure(struct elmcan *elm)
{
struct can_frame *frame;
struct sk_buff *skb;
lockdep_assert_held(elm->lock);
- elm->hw_failure = true;
+ elm->uart_side_failure = true;
elm->can.can_stats.bus_off++;
netif_stop_queue(elm->dev);
*/
netdev_err(elm->dev,
"RX buffer overflow. Faulty ELM327 or UART?\n");
- elm327_hw_failure(elm);
+ elm327_uart_side_failure(elm);
break;
} else if (len == elm->rxfill) {
if (elm327_is_ready_char(elm->rxbuf[elm->rxfill - 1])) {
int err;
spin_lock_bh(&elm->lock);
- if (elm->hw_failure) {
+ if (elm->uart_side_failure) {
netdev_err(elm->dev, "Refusing to open interface after a hardware fault has been detected.\n");
spin_unlock_bh(&elm->lock);
return -EIO;
/* We shouldn't get here after a hardware fault:
* can_bus_off() calls netif_carrier_off()
*/
- WARN_ON_ONCE(elm->hw_failure);
+ WARN_ON_ONCE(elm->uart_side_failure);
if (!elm->tty ||
- elm->hw_failure ||
+ elm->uart_side_failure ||
elm->can.ctrlmode & CAN_CTRLMODE_LISTENONLY) {
spin_unlock(&elm->lock);
goto out;
spin_lock_bh(&elm->lock);
- if (elm->hw_failure)
+ if (elm->uart_side_failure)
goto out;
while (count-- && elm->rxfill < ELM327_SIZE_RXBUF) {
if (fp && *fp++) {
netdev_err(elm->dev, "Error in received character stream. Check your wiring.");
- elm327_hw_failure(elm);
+ elm327_uart_side_failure(elm);
goto out;
}
netdev_err(elm->dev,
"Received illegal character %02x.\n",
*cp);
- elm327_hw_failure(elm);
+ elm327_uart_side_failure(elm);
goto out;
}
if (count >= 0) {
netdev_err(elm->dev, "Receive buffer overflowed. Bad chip or wiring?");
- elm327_hw_failure(elm);
+ elm327_uart_side_failure(elm);
goto out;
}
struct elmcan *elm = container_of(work, struct elmcan, tx_work);
ssize_t written;
- if (elm->hw_failure)
+ if (elm->uart_side_failure)
return;
spin_lock_bh(&elm->lock);
netdev_err(elm->dev,
"Failed to write to tty %s.\n",
elm->tty->name);
- elm327_hw_failure(elm);
+ elm327_uart_side_failure(elm);
spin_unlock_bh(&elm->lock);
return;
} else {