[PATCH 03/35] n_tty: remove n_tty_receive_char_fast

From: Jiri Slaby
Date: Wed May 05 2021 - 05:19:42 EST


n_tty_receive_char_fast is a copy of n_tty_receive_char with one
exception: PARMRK is not doubled in the former. Unify these two and
double PARMRK depending on a newly added parameter (bool parmrk_dbl).

I don't think the theoretical speedup is worth the code duplication.
Which is directly connected with maintenance burden.

Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
drivers/tty/n_tty.c | 32 ++++++--------------------------
1 file changed, 6 insertions(+), 26 deletions(-)

diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index 0a8c9440f5d2..0adc79bae839 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -1400,8 +1400,8 @@ n_tty_receive_char_special(struct tty_struct *tty, unsigned char c)
return 0;
}

-static inline void
-n_tty_receive_char(struct tty_struct *tty, unsigned char c)
+static void n_tty_receive_char(struct tty_struct *tty, unsigned char c,
+ bool parmrk_dbl)
{
struct n_tty_data *ldata = tty->disc_data;

@@ -1418,31 +1418,11 @@ n_tty_receive_char(struct tty_struct *tty, unsigned char c)
commit_echoes(tty);
}
/* PARMRK doubling check */
- if (c == (unsigned char) '\377' && I_PARMRK(tty))
+ if (parmrk_dbl && c == (unsigned char) '\377' && I_PARMRK(tty))
put_tty_queue(c, ldata);
put_tty_queue(c, ldata);
}

-static inline void
-n_tty_receive_char_fast(struct tty_struct *tty, unsigned char c)
-{
- struct n_tty_data *ldata = tty->disc_data;
-
- if (tty->stopped && !tty->flow_stopped && I_IXON(tty) && I_IXANY(tty)) {
- start_tty(tty);
- process_echoes(tty);
- }
- if (L_ECHO(tty)) {
- finish_erasing(ldata);
- /* Record the column of first canon char. */
- if (ldata->canon_head == ldata->read_head)
- echo_set_canon_col(ldata);
- echo_char(c, tty);
- commit_echoes(tty);
- }
- put_tty_queue(c, ldata);
-}
-
static void n_tty_receive_char_closing(struct tty_struct *tty, unsigned char c)
{
if (I_ISTRIP(tty))
@@ -1494,7 +1474,7 @@ n_tty_receive_char_lnext(struct tty_struct *tty, unsigned char c, char flag)
c &= 0x7f;
if (I_IUCLC(tty) && L_IEXTEN(tty))
c = tolower(c);
- n_tty_receive_char(tty, c);
+ n_tty_receive_char(tty, c, true);
} else
n_tty_receive_char_flagged(tty, c, flag);
}
@@ -1572,7 +1552,7 @@ n_tty_receive_buf_standard(struct tty_struct *tty, const unsigned char *cp,
continue;
}
if (!test_bit(c, ldata->char_map))
- n_tty_receive_char(tty, c);
+ n_tty_receive_char(tty, c, true);
else if (n_tty_receive_char_special(tty, c) && count) {
if (fp)
flag = *fp++;
@@ -1598,7 +1578,7 @@ n_tty_receive_buf_fast(struct tty_struct *tty, const unsigned char *cp,
unsigned char c = *cp++;

if (!test_bit(c, ldata->char_map))
- n_tty_receive_char_fast(tty, c);
+ n_tty_receive_char(tty, c, false);
else if (n_tty_receive_char_special(tty, c) && count) {
if (fp)
flag = *fp++;
--
2.31.1