From 73c3d53f38e0a8e6c67b0d12d77a8e77c082cd03 Mon Sep 17 00:00:00 2001 From: Paul Mundt Date: Fri, 2 Dec 2011 19:02:06 +0900 Subject: [PATCH] serial: sh-sci: Avoid FIFO clear for MCE toggle. When toggling the MCE support we don't want to concern ourselves with the FIFO state, so ensure that the clearing bits are masked out when updating the MCE state. Signed-off-by: Paul Mundt --- drivers/tty/serial/sh-sci.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index fd60d72eac89..761a800cb483 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -1771,18 +1771,25 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios, sci_init_pins(port, termios->c_cflag); - if (s->cfg->capabilities & SCIx_HAVE_RTSCTS) { - reg = sci_getreg(port, SCFCR); - if (reg->size) { - unsigned short ctrl; + reg = sci_getreg(port, SCFCR); + if (reg->size) { + unsigned short ctrl = sci_in(port, SCFCR); - ctrl = sci_in(port, SCFCR); + if (s->cfg->capabilities & SCIx_HAVE_RTSCTS) { if (termios->c_cflag & CRTSCTS) ctrl |= SCFCR_MCE; else ctrl &= ~SCFCR_MCE; - sci_out(port, SCFCR, ctrl); } + + /* + * As we've done a sci_reset() above, ensure we don't + * interfere with the FIFOs while toggling MCE. As the + * reset values could still be set, simply mask them out. + */ + ctrl &= ~(SCFCR_RFRST | SCFCR_TFRST); + + sci_out(port, SCFCR, ctrl); } sci_out(port, SCSCR, s->cfg->scscr); -- 2.20.1