Subject: [PATCH 2/2] atmel_serial: Implement flush_buffer() hook
Avoid dumping garbage to the serial port when the tty is flushed. This
tends to happen when rebooting from a serial console.
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/serial/atmel_serial.c b/drivers/serial/atmel_serial.c
index 6aeef22b..c17fcd6 100644
--- a/drivers/serial/atmel_serial.c
+++ b/drivers/serial/atmel_serial.c
@@ -956,6 +956,20 @@
}
/*
+ * Flush any TX data submitted for DMA. Called when the TX circular
+ * buffer is reset.
+ */
+static void atmel_flush_buffer(struct uart_port *port)
+{
+ struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+
+ if (atmel_use_dma_tx(port)) {
+ UART_PUT_TCR(port, 0);
+ atmel_port->pdc_tx.ofs = 0;
+ }
+}
+
+/*
* Power / Clock management.
*/
static void atmel_serial_pm(struct uart_port *port, unsigned int state,
@@ -1189,6 +1203,7 @@
.break_ctl = atmel_break_ctl,
.startup = atmel_startup,
.shutdown = atmel_shutdown,
+ .flush_buffer = atmel_flush_buffer,
.set_termios = atmel_set_termios,
.type = atmel_type,
.release_port = atmel_release_port,