sunsab: Fix detection of BREAK on sunsab serial console

Fix detection of BREAK on sunsab serial console: BREAK detection was only
performed when there were also serial characters received simultaneously.
To handle all BREAKs correctly, the check for BREAK and the corresponding
call to uart_handle_break() must also be done if count == 0, therefore
duplicate this code fragment and pull it out of the loop over the received
characters.

Patch applies to 3.16-rc6.

Signed-off-by: Christopher Alexander Tobias Schulze <cat.schulze@alice-dsl.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 0 deletions

diff --git a/drivers/tty/serial/sunsab.c b/drivers/tty/serial/sunsab.c
index 2f57df9a71d9..a1e09c0d46f2 100644
--- a/drivers/tty/serial/sunsab.c
+++ b/drivers/tty/serial/sunsab.c
@@ -157,6 +157,15 @@ receive_chars(struct uart_sunsab_port *up,
             (up->port.line == up->port.cons->index))
                 saw_console_brk = 1;
 
+        if (count == 0) {
+                if (unlikely(stat->sreg.isr1 & SAB82532_ISR1_BRK)) {
+                        stat->sreg.isr0 &= ~(SAB82532_ISR0_PERR |
+                                             SAB82532_ISR0_FERR);
+                        up->port.icount.brk++;
+                        uart_handle_break(&up->port);
+                }
+        }
+
         for (i = 0; i < count; i++) {
                 unsigned char ch = buf[i], flag;