serial: sunsab: Don't enable tx if tx stopped
The serial core may call the UART driver's start_tx() even if
tx is stopped; the UART driver must verify tx should be enabled
before transmitting.
Reported-by: Sam Ravnborg <sam@ravnborg.org>
cc: David S. Miller <davem@davemloft.net>
cc: <sparclinux@vger.kernel.org>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/serial/sunsab.c b/drivers/tty/serial/sunsab.c
index 0af75f8..b339fe4 100644
--- a/drivers/tty/serial/sunsab.c
+++ b/drivers/tty/serial/sunsab.c
@@ -436,7 +436,7 @@
struct circ_buf *xmit = &up->port.state->xmit;
int i;
- if (uart_circ_empty(xmit))
+ if (uart_circ_empty(xmit) || uart_tx_stopped(port))
return;
up->interrupt_mask1 &= ~(SAB82532_IMR1_ALLS|SAB82532_IMR1_XPR);