1 files changed, 30 insertions, 2 deletions

diff --git a/drivers/serial/atmel_serial.c b/drivers/serial/atmel_serial.c
index 3320bcd92c0a..4d6b3c56d20e 100644
--- a/drivers/serial/atmel_serial.c
+++ b/drivers/serial/atmel_serial.c
@@ -114,6 +114,7 @@ struct atmel_uart_port {
         struct uart_port        uart;           /* uart */
         struct clk              *clk;           /* uart clock */
         unsigned short          suspended;      /* is port suspended? */
+        int                     break_active;   /* break being received */
 };
 
 static struct atmel_uart_port atmel_ports[ATMEL_MAX_UART];
@@ -252,6 +253,7 @@ static void atmel_break_ctl(struct uart_port *port, int break_state)
  */
 static void atmel_rx_chars(struct uart_port *port)
 {
+        struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;
         struct tty_struct *tty = port->info->tty;
         unsigned int status, ch, flg;
 
@@ -267,13 +269,29 @@ static void atmel_rx_chars(struct uart_port *port)
                  * note that the error handling code is
                  * out of the main execution path
                  */
-                if (unlikely(status & (ATMEL_US_PARE | ATMEL_US_FRAME | ATMEL_US_OVRE | ATMEL_US_RXBRK))) {
+                if (unlikely(status & (ATMEL_US_PARE | ATMEL_US_FRAME
+                                       | ATMEL_US_OVRE | ATMEL_US_RXBRK)
+                             || atmel_port->break_active)) {
                         UART_PUT_CR(port, ATMEL_US_RSTSTA);     /* clear error */
-                        if (status & ATMEL_US_RXBRK) {
+                        if (status & ATMEL_US_RXBRK
+                            && !atmel_port->break_active) {
                                 status &= ~(ATMEL_US_PARE | ATMEL_US_FRAME);    /* ignore side-effect */
                                 port->icount.brk++;
+                                atmel_port->break_active = 1;
+                                UART_PUT_IER(port, ATMEL_US_RXBRK);
                                 if (uart_handle_break(port))
                                         goto ignore_char;
+                        } else {
+                                /*
+                                 * This is either the end-of-break
+                                 * condition or we've received at
+                                 * least one character without RXBRK
+                                 * being set. In both cases, the next
+                                 * RXBRK will indicate start-of-break.
+                                 */
+                                UART_PUT_IDR(port, ATMEL_US_RXBRK);
+                                status &= ~ATMEL_US_RXBRK;
+                                atmel_port->break_active = 0;
                         }
                         if (status & ATMEL_US_PARE)
                                 port->icount.parity++;
@@ -352,6 +370,16 @@ static irqreturn_t atmel_interrupt(int irq, void *dev_id)
                 /* Interrupt receive */
                 if (pending & ATMEL_US_RXRDY)
                         atmel_rx_chars(port);
+                else if (pending & ATMEL_US_RXBRK) {
+                        /*
+                         * End of break detected. If it came along
+                         * with a character, atmel_rx_chars will
+                         * handle it.
+                         */
+                        UART_PUT_CR(port, ATMEL_US_RSTSTA);
+                        UART_PUT_IDR(port, ATMEL_US_RXBRK);
+                        atmel_port->break_active = 0;
+                }
 
                 // TODO: All reads to CSR will clear these interrupts!
                 if (pending & ATMEL_US_RIIC) port->icount.rng++;