From 44763d3d301a13523186731b4797b181c78fe8b4 Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Fri, 24 Jun 2016 16:59:13 +0200 Subject: [PATCH] serial: sh-sci: Do not start transfers from sci_startup() FIFO reset is done in sci_reset(), called from sci_set_termios(), while sci_start_tx() and sci_start_rx() are called before, from sci_startup(). However, starting transfers before the UART's FIFOs have been reset may cause reading of stale data. Remove the calls to sci_start_tx() and sci_start_rx() from sci_startup() to fix this. Transfers are still started when needed: - sci_start_rx() is called from sci_set_termios() after FIFO reset, if the CREAD flag is set, - sci_start_tx() is called from uart_change_speed() immediately thereafter, if transmission is enabled. Signed-off-by: Geert Uytterhoeven Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/sh-sci.c | 6 ------ 1 file changed, 6 deletions(-) diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index d9cb0d70fcee..d88c84cd88a4 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -1972,7 +1972,6 @@ static void sci_break_ctl(struct uart_port *port, int break_state) static int sci_startup(struct uart_port *port) { struct sci_port *s = to_sci_port(port); - unsigned long flags; int ret; dev_dbg(port->dev, "%s(%d)\n", __func__, port->line); @@ -1983,11 +1982,6 @@ static int sci_startup(struct uart_port *port) sci_request_dma(port); - spin_lock_irqsave(&port->lock, flags); - sci_start_tx(port); - sci_start_rx(port); - spin_unlock_irqrestore(&port->lock, flags); - return 0; }