diff options
| -rw-r--r-- | module/elmcan.c | 36 |
1 files changed, 19 insertions, 17 deletions
diff --git a/module/elmcan.c b/module/elmcan.c index 9c19d76..6a7b951 100644 --- a/module/elmcan.c +++ b/module/elmcan.c @@ -96,10 +96,12 @@ struct elmcan { /* 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 */ @@ -133,7 +135,7 @@ struct elmcan { 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) { @@ -141,7 +143,7 @@ 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); @@ -151,7 +153,7 @@ static void elm327_send(struct elmcan *elm, const void *buf, size_t 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; } @@ -294,14 +296,14 @@ static void elm327_feed_frame_to_netdev(struct elmcan *elm, } /* 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); @@ -719,7 +721,7 @@ static void elm327_parse_rxbuf(struct elmcan *elm) */ 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])) { @@ -769,7 +771,7 @@ static int elmcan_netdev_open(struct net_device *dev) 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; @@ -860,10 +862,10 @@ static netdev_tx_t elmcan_netdev_start_xmit(struct sk_buff *skb, /* 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; @@ -923,14 +925,14 @@ static void elmcan_ldisc_rx(struct tty_struct *tty, 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; } @@ -948,7 +950,7 @@ static void elmcan_ldisc_rx(struct tty_struct *tty, netdev_err(elm->dev, "Received illegal character %02x.\n", *cp); - elm327_hw_failure(elm); + elm327_uart_side_failure(elm); goto out; } @@ -962,7 +964,7 @@ static void elmcan_ldisc_rx(struct tty_struct *tty, 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; } @@ -981,7 +983,7 @@ static void elmcan_ldisc_tx_worker(struct work_struct *work) 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); @@ -992,7 +994,7 @@ static void elmcan_ldisc_tx_worker(struct work_struct *work) 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 { |