This is a note to let you know that I've just added the patch titled
serial: sh-sci: Make sure status register SCxSR is read in correct
to my tty git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git in the tty-linus branch.
The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.
If you have any questions about this process, please let me know.
From 3dc4db3662366306e54ddcbda4804acb1258e4ba Mon Sep 17 00:00:00 2001
From: Kazuhiro Fujita kazuhiro.fujita.jg@renesas.com Date: Fri, 27 Mar 2020 18:17:28 +0000 Subject: serial: sh-sci: Make sure status register SCxSR is read in correct sequence
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 | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index c073aa7001c4..e1179e74a2b8 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -870,9 +870,16 @@ static void sci_receive_chars(struct uart_port *port) tty_insert_flip_char(tport, c, TTY_NORMAL); } else { for (i = 0; i < count; i++) { - char c = serial_port_in(port, SCxRDR); - - status = serial_port_in(port, SCxSR); + char c; + + 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;