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authorKazuhiro Fujita <kazuhiro.fujita.jg@renesas.com>2020-03-27 18:17:28 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-04-16 16:16:52 +0200
commit3dc4db3662366306e54ddcbda4804acb1258e4ba (patch)
tree688fd4a8b7e5f6220c23b1f5d89ffb31ed266878 /drivers/tty
parent0f87aa66e8c314f95c00eeff978c8a0b41e05d50 (diff)
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.jg@renesas.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
-rw-r--r--drivers/tty/serial/sh-sci.c13
1 files 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;