lkml.org 
[lkml]   [2022]   [Apr]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2 1/3] tty: Add functions for handling flow control chars
Date
Move receive path flow control character handling to own function
and a helper.

This seems cleanest approach especially once skipping due to lookahead
is added. Its downside is the duplicated START_CHAR and STOP_CHAR
checks.

No functional changes.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---
drivers/tty/n_tty.c | 34 +++++++++++++++++++++++-----------
1 file changed, 23 insertions(+), 11 deletions(-)

diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index efc72104c840..90b3e06cbeb1 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -1220,21 +1220,33 @@ n_tty_receive_signal_char(struct tty_struct *tty, int signal, unsigned char c)
process_echoes(tty);
}

+static bool n_tty_is_char_flow_ctrl(struct tty_struct *tty, unsigned char c)
+{
+ return c == START_CHAR(tty) || c == STOP_CHAR(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 (!n_tty_is_char_flow_ctrl(tty, c))
+ return false;
+
+ if (c == START_CHAR(tty)) {
+ start_tty(tty);
+ process_echoes(tty);
+ } else if (c == STOP_CHAR(tty)) {
+ stop_tty(tty);
+ }
+
+ return true;
+}
+
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
\
 
 \ /
  Last update: 2022-04-08 13:41    [W:0.080 / U:1.260 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site