On Wed, 16 Aug 2023, Jiri Slaby (SUSE) wrote:
> 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@kernel.org>
> ---
> 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;
Type might be better but these two don't look like a major improvement...
To me it seems obvious there exists some variable name that is better than
c or retval for this purpose. ;-)
--
i.