Restart on error instead of stopping

diff --git a/module/elmcan.c b/module/elmcan.c
index 3d35821fae7d34e0b707d96d8f80146af942ba55..66cc3706f752bbf8fab4b86c39f620032cca8eb6 100644 (file)
--- a/module/elmcan.c
+++ b/module/elmcan.c
@@ -96,11 +96,6 @@ struct elmcan {
         */
        atomic_t                refcount;
 
-       /* Stop the channel on hardware failure.
-        * Once this is true, nothing will be sent to the TTY.
-        */
-       bool                    hw_failure;
-
        /* TTY TX helpers */
        struct work_struct      tx_work;        /* Flushes TTY TX buffer   */
        unsigned char           *txbuf;
@@ -149,9 +144,6 @@ static void elm327_send(struct elmcan *elm, const void *buf, size_t len)
 {
        int actual;
 
-       if (elm->hw_failure)
-               return;
-
        memcpy(elm->txbuf, buf, len);
 
        /* Order of next two lines is *very* important.
@@ -168,7 +160,6 @@ 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);
                return;
        }
 
@@ -321,17 +312,16 @@ static inline void elm327_hw_failure(struct elmcan *elm)
        struct can_frame frame;
 
        memset(&frame, 0, sizeof(frame));
-       frame.can_id = CAN_ERR_FLAG;
+       frame.can_id = CAN_ERR_FLAG | CAN_ERR_RESTARTED;
        frame.can_dlc = CAN_ERR_DLC;
        frame.data[5] = 'R';
        frame.data[6] = 'I';
        frame.data[7] = 'P';
        elm327_feed_frame_to_netdev(elm, &frame);
 
-       netdev_err(elm->dev, "ELM327 misbehaved. Blocking further communication.\n");
+       netdev_err(elm->dev, "ELM327 misbehaved. Restarting. Watch for error CAN frames.\n");
 
-       elm->hw_failure = true;
-       can_bus_off(elm->dev);
+       elm327_init(elm);
 }
 
 /* Compare a buffer to a fixed string */
@@ -769,11 +759,6 @@ static int elmcan_netdev_open(struct net_device *dev)
        int err;
 
        spin_lock_bh(&elm->lock);
-       if (elm->hw_failure) {
-               netdev_err(elm->dev, "Refusing to open interface after a hardware fault has been detected.\n");
-               spin_unlock_bh(&elm->lock);
-               return -EIO;
-       }
 
        if (!elm->tty) {
                spin_unlock_bh(&elm->lock);
@@ -858,13 +843,7 @@ static netdev_tx_t elmcan_netdev_start_xmit(struct sk_buff *skb,
         */
        spin_lock(&elm->lock);
 
-       /* We shouldn't get here after a hardware fault:
-        * can_bus_off() calls netif_carrier_off()
-        */
-       WARN_ON_ONCE(elm->hw_failure);
-
        if (!elm->tty ||
-           elm->hw_failure ||
            elm->can.ctrlmode & CAN_CTRLMODE_LISTENONLY) {
                spin_unlock(&elm->lock);
                goto out;
@@ -960,9 +939,6 @@ static void elmcan_ldisc_rx(struct tty_struct *tty,
 
        spin_lock_bh(&elm->lock);
 
-       if (elm->hw_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.");
@@ -1023,10 +999,6 @@ static void elmcan_ldisc_tx_worker(struct work_struct *work)
        ssize_t actual;
 
        spin_lock_bh(&elm->lock);
-       if (elm->hw_failure) {
-               spin_unlock_bh(&elm->lock);
-               return;
-       }
 
        if (!elm->tty || !netif_running(elm->dev)) {
                spin_unlock_bh(&elm->lock);