[PATCH 03/14] tty: n_tty: use 'retval' for writes' retvals

[Jiri Slaby (SUSE)]

We have a separate misnomer 'c' to hold the retuned value from
tty->ops->write(). Instead, use already defined and properly typed
'retval'.

We have another variable 'num' to serve the same purpose in the OPOST
branch. We can use this 'retval' too. But just clear it in case of
EAGAIN.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@xxxxxxxxxx>
---
 drivers/tty/n_tty.c | 30 ++++++++++++++----------------
 1 file changed, 14 insertions(+), 16 deletions(-)

diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index f6fa4dbdf78f..e293d87b5362 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -2335,7 +2335,6 @@ static ssize_t n_tty_write(struct tty_struct *tty, struct file *file,
 {
 	const u8 *b = buf;
 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
-	int c;
 	ssize_t retval = 0;
 
 	/* Job control check -- must be done at start (POSIX.1 7.1.1.4). */
@@ -2362,15 +2361,16 @@ static ssize_t n_tty_write(struct tty_struct *tty, struct file *file,
 		}
 		if (O_OPOST(tty)) {
 			while (nr > 0) {
-				ssize_t num = process_output_block(tty, b, nr);
-				if (num < 0) {
-					if (num == -EAGAIN)
-						break;
-					retval = num;
-					goto break_out;
+				retval = process_output_block(tty, b, nr);
+				if (retval == -EAGAIN) {
+					retval = 0;
+					break;
 				}
-				b += num;
-				nr -= num;
+				if (retval < 0)
+					goto break_out;
+
+				b += retval;
+				nr -= retval;
 				if (nr == 0)
 					break;
 				if (process_output(*b, tty) < 0)
@@ -2384,16 +2384,14 @@ static ssize_t n_tty_write(struct tty_struct *tty, struct file *file,
 
 			while (nr > 0) {
 				mutex_lock(&ldata->output_lock);
-				c = tty->ops->write(tty, b, nr);
+				retval = tty->ops->write(tty, b, nr);
 				mutex_unlock(&ldata->output_lock);
-				if (c < 0) {
-					retval = c;
+				if (retval < 0)
 					goto break_out;
-				}
-				if (!c)
+				if (!retval)
 					break;
-				b += c;
-				nr -= c;
+				b += retval;
+				nr -= retval;
 			}
 		}
 		if (!nr)
-- 
2.41.0