From: Kazuhiro Fujita kazuhiro.fujita.jg@renesas.com
commit 3dc4db3662366306e54ddcbda4804acb1258e4ba upstream.
For SCIF and HSCIF interfaces the SCxSR register holds the status of data that is to be read next from SCxRDR register, But where as for SCIFA and SCIFB interfaces SCxSR register holds status of data that is previously read from SCxRDR register.
This patch makes sure the status register is read depending on the port types so that errors are caught accordingly.
Cc: stable@vger.kernel.org Signed-off-by: Kazuhiro Fujita kazuhiro.fujita.jg@renesas.com Signed-off-by: Hao Bui hao.bui.yg@renesas.com Signed-off-by: KAZUMI HARADA kazumi.harada.rh@renesas.com Signed-off-by: Lad Prabhakar prabhakar.mahadev-lad.rj@bp.renesas.com Tested-by: Geert Uytterhoeven geert+renesas@glider.be Link: https://lore.kernel.org/r/1585333048-31828-1-git-send-email-kazuhiro.fujita.... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/tty/serial/sh-sci.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)
--- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -841,9 +841,16 @@ static void sci_receive_chars(struct uar tty_insert_flip_char(tport, c, TTY_NORMAL); } else { for (i = 0; i < count; i++) { - char c = serial_port_in(port, SCxRDR); + char c;
- status = serial_port_in(port, SCxSR); + if (port->type == PORT_SCIF || + port->type == PORT_HSCIF) { + status = serial_port_in(port, SCxSR); + c = serial_port_in(port, SCxRDR); + } else { + c = serial_port_in(port, SCxRDR); + status = serial_port_in(port, SCxSR); + } if (uart_handle_sysrq_char(port, c)) { count--; i--; continue;