Only netif_wake_queue() when ELM327 is really idle

That is, when it is receiving, as that's the default state the driver
tries its best to keep it in.

diff --git a/module/elmcan.c b/module/elmcan.c
index 85c656585f1551bea4328b16a8f1fcc7021dfe3e..3afbbc4d4989fd85842078a7a13fb607c7ec1c3b 100644 (file)
--- a/module/elmcan.c
+++ b/module/elmcan.c
@@ -161,9 +161,7 @@ static void elm327_send(struct elmcan *elm, const void *buf, size_t len)
        elm->txleft = len - written;
        elm->txhead = elm->txbuf + written;
 
-       if (!elm->txleft)
-               netif_wake_queue(elm->dev);
-       else
+       if (elm->txleft)
                set_bit(TTY_DO_WRITE_WAKEUP, &elm->tty->flags);
 }
 
@@ -573,6 +571,11 @@ static void elm327_handle_prompt(struct elmcan *elm)
                elm327_send(elm, "ATMA\r", 5);
                elm->state = ELM327_STATE_RECEIVING;
 
+               /* We will be in the default state once this command is
+                * send, so enable the TX packet queue.
+                */
+               netif_wake_queue(elm->dev);
+
                return;
        }
 
@@ -646,6 +649,11 @@ static void elm327_handle_prompt(struct elmcan *elm)
 
                elm->drop_next_line = 1;
                elm->state = ELM327_STATE_RECEIVING;
+
+               /* We will be in the default state once this command is
+                * send, so enable the TX packet queue.
+                */
+               netif_wake_queue(elm->dev);
        }
 
        elm327_send(elm, local_txbuf, strlen(local_txbuf));
@@ -824,15 +832,12 @@ static int elmcan_netdev_close(struct net_device *dev)
        elm327_send(elm, ELM327_DUMMY_STRING, 1);
        spin_unlock_bh(&elm->lock);
 
-       /* Give UART one final chance to flush.
-        * This may netif_wake_queue(), so don't netif_stop_queue()
-        * before flushing the worker.
-        */
+       netif_stop_queue(dev);
+
+       /* Give UART one final chance to flush. */
        clear_bit(TTY_DO_WRITE_WAKEUP, &elm->tty->flags);
        flush_work(&elm->tx_work);
 
-       netif_stop_queue(dev);
-
        can_rx_offload_disable(&elm->offload);
        elm->can.state = CAN_STATE_STOPPED;
        can_rx_offload_del(&elm->offload);
@@ -1004,7 +1009,6 @@ static void elmcan_ldisc_tx_worker(struct work_struct *work)
        if (!elm->txleft)  {
                clear_bit(TTY_DO_WRITE_WAKEUP, &elm->tty->flags);
                spin_unlock_bh(&elm->lock);
-               netif_wake_queue(elm->dev);
        } else {
                spin_unlock_bh(&elm->lock);
        }