From 9afd561acabe5059ff16d163a176e2350269aba5 Mon Sep 17 00:00:00 2001 From: Haavard Skinnemoen Date: Wed, 16 Jul 2008 21:52:46 +0100 Subject: [PATCH] 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 Acked-by: Alan Cox Signed-off-by: Linus Torvalds --- drivers/serial/atmel_serial.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/drivers/serial/atmel_serial.c b/drivers/serial/atmel_serial.c index 6aeef22bd2..c17fcd6085 100644 --- a/drivers/serial/atmel_serial.c +++ b/drivers/serial/atmel_serial.c @@ -955,6 +955,20 @@ static void atmel_shutdown(struct uart_port *port) atmel_close_hook(port); } +/* + * 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. */ @@ -1189,6 +1203,7 @@ static struct uart_ops atmel_pops = { .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, -- 2.39.5