Rename hw_failure to uart_side_failure for easier understanding

diff --git a/module/elmcan.c b/module/elmcan.c
index 9c19d76e141606ad8e52c4e56843d973f2fd9e05..6a7b95127bb828fcb861e8b0bd45ac6db742958d 100644 (file)
--- 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 {