tty: n_tty: simplify chars_in_buffer()

Jiri Slaby (SUSE) · gregkh · commit d88c3c2675f9 · 2023-08-27T11:46:52.000+02:00
The 'if' in chars_in_buffer() is misleadingly inverted. And since the only difference is the head used for computation, cache the head using ternary operator. And use that in return directly. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20230827074147.2287-11-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
@@ -219,13 +219,9 @@ static void n_tty_kick_worker(const struct tty_struct *tty)
 static ssize_t chars_in_buffer(const struct tty_struct *tty)
 {
 	const struct n_tty_data *ldata = tty->disc_data;
-	ssize_t n = 0;
+	size_t head = ldata->icanon ? ldata->canon_head : ldata->commit_head;
 
-	if (!ldata->icanon)
-		n = ldata->commit_head - ldata->read_tail;
-	else
-		n = ldata->canon_head - ldata->read_tail;
-	return n;
+	return head - ldata->read_tail;
 }
 
 /**

Original file line number	Diff line number	Diff line change
`@@ -219,13 +219,9 @@ static void n_tty_kick_worker(const struct tty_struct *tty)`
`219`	`219`	`static ssize_t chars_in_buffer(const struct tty_struct *tty)`
`220`	`220`	`{`
`221`	`221`	`const struct n_tty_data *ldata = tty->disc_data;`
`222`		`- ssize_t n = 0;`
	`222`	`+ size_t head = ldata->icanon ? ldata->canon_head : ldata->commit_head;`
`223`	`223`
`224`		`- if (!ldata->icanon)`
`225`		`- n = ldata->commit_head - ldata->read_tail;`
`226`		`- else`
`227`		`- n = ldata->canon_head - ldata->read_tail;`
`228`		`- return n;`
	`224`	`+ return head - ldata->read_tail;`
`229`	`225`	`}`
`230`	`226`
`231`	`227`	`/**`