1 files changed, 15 insertions, 0 deletions

diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index 0d934bfbdd9b..b4b39811b445 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -2083,6 +2083,20 @@ static int serial8250_startup(struct uart_port *port)
 
         serial8250_set_mctrl(&up->port, up->port.mctrl);
 
+        /* Serial over Lan (SoL) hack:
+           Intel 8257x Gigabit ethernet chips have a
+           16550 emulation, to be used for Serial Over Lan.
+           Those chips take a longer time than a normal
+           serial device to signalize that a transmission
+           data was queued. Due to that, the above test generally
+           fails. One solution would be to delay the reading of
+           iir. However, this is not reliable, since the timeout
+           is variable. So, let's just don't test if we receive
+           TX irq. This way, we'll never enable UART_BUG_TXEN.
+         */
+        if (up->port.flags & UPF_NO_TXEN_TEST)
+                goto dont_test_tx_en;
+
         /*
          * Do a quick test to see if we receive an
          * interrupt when we enable the TX irq.
@@ -2102,6 +2116,7 @@ static int serial8250_startup(struct uart_port *port)
                 up->bugs &= ~UART_BUG_TXEN;
         }
 
+dont_test_tx_en:
         spin_unlock_irqrestore(&up->port.lock, flags);
 
         /*