Commit 73276e3a authored by Jiri Slaby (SUSE)'s avatar Jiri Slaby (SUSE) Committed by Greg Kroah-Hartman
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tty: n_tty: use time_is_before_jiffies() in n_tty_receive_overrun() 



The jiffies tests in n_tty_receive_overrun() are simplified ratelimiting
(without locking). We could use struct ratelimit_state and the helpers,
but to me, it occurs to be too complex for this use case.

But the code currently tests both if the time passed (the first
time_after()) and if jiffies wrapped around (the second time_after()).
time_is_before_jiffies() takes care of both, provided overrun_time is
initialized at the allocation time.

So switch to time_is_before_jiffies(), the same what ratelimiting does.

Signed-off-by: default avatar"Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20230827074147.2287-5-jirislaby@kernel.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 68d90d5f

drivers/tty/n_tty.c

+1 −2
Original line number Diff line number Diff line
@@ -1173,8 +1173,7 @@ static void n_tty_receive_overrun(const struct tty_struct *tty) 
	struct n_tty_data *ldata = tty->disc_data;



	ldata->num_overrun++;

	if (time_after(jiffies, ldata->overrun_time + HZ) ||

	    time_after(ldata->overrun_time, jiffies)) {

	if (time_is_before_jiffies(ldata->overrun_time + HZ)) {

		tty_warn(tty, "%d input overrun(s)\n", ldata->num_overrun);

		ldata->overrun_time = jiffies;

		ldata->num_overrun = 0;