[PATCH v3 1/5] tty: Add function for handling flow control chars

From: Ilpo Järvinen
Date: Mon Apr 11 2022 - 05:50:18 EST


Move receive path flow control character handling to own function.

No functional changes.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
---
drivers/tty/n_tty.c | 29 ++++++++++++++++++-----------
1 file changed, 18 insertions(+), 11 deletions(-)

diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index efc72104c840..c7edfc001fd0 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -1220,21 +1220,28 @@ n_tty_receive_signal_char(struct tty_struct *tty, int signal, unsigned char c)
process_echoes(tty);
}

+/* Returns true if c is consumed as flow-control character */
+static bool n_tty_receive_char_flow_ctrl(struct tty_struct *tty, unsigned char c)
+{
+ if (c == START_CHAR(tty)) {
+ start_tty(tty);
+ process_echoes(tty);
+ return true;
+ }
+ if (c == STOP_CHAR(tty)) {
+ stop_tty(tty);
+ return true;
+ }
+
+ return false;
+}
+
static void n_tty_receive_char_special(struct tty_struct *tty, unsigned char c)
{
struct n_tty_data *ldata = tty->disc_data;

- if (I_IXON(tty)) {
- if (c == START_CHAR(tty)) {
- start_tty(tty);
- process_echoes(tty);
- return;
- }
- if (c == STOP_CHAR(tty)) {
- stop_tty(tty);
- return;
- }
- }
+ if (I_IXON(tty) && n_tty_receive_char_flow_ctrl(tty, c))
+ return;

if (L_ISIG(tty)) {
if (c == INTR_CHAR(tty)) {
--
2.30.2