It makes the code both more compact, and more understandable.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
---
 drivers/tty/tty_buffer.c | 13 +++----------
 1 file changed, 3 insertions(+), 10 deletions(-)

diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c
index 414bb7f9155f..44c0adaec850 100644
--- a/drivers/tty/tty_buffer.c
+++ b/drivers/tty/tty_buffer.c
@@ -262,17 +262,10 @@ static int __tty_buffer_request_room(struct tty_port *port, size_t size,
 				     bool flags)
 {
 	struct tty_bufhead *buf = &port->buf;
-	struct tty_buffer *b, *n;
-	size_t left;
-	bool change;
+	struct tty_buffer *n, *b = buf->tail;
+	size_t left = (b->flags ? 1 : 2) * b->size - b->used;
+	bool change = !b->flags && flags;
 
-	b = buf->tail;
-	if (!b->flags)
-		left = 2 * b->size - b->used;
-	else
-		left = b->size - b->used;
-
-	change = !b->flags && flags;
 	if (change || left < size) {
 		/* This is the slow path - looking for new buffers to use */
 		n = tty_buffer_alloc(port, size);
-- 
2.41.0

On Wed, Aug 16, 2023 at 12:55:29PM +0200, Jiri Slaby (SUSE) wrote:
> It makes the code both more compact, and more understandable.
> 
> Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
> ---
>  drivers/tty/tty_buffer.c | 13 +++----------
>  1 file changed, 3 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c
> index 414bb7f9155f..44c0adaec850 100644
> --- a/drivers/tty/tty_buffer.c
> +++ b/drivers/tty/tty_buffer.c
> @@ -262,17 +262,10 @@ static int __tty_buffer_request_room(struct tty_port *port, size_t size,
>  				     bool flags)
>  {
>  	struct tty_bufhead *buf = &port->buf;
> -	struct tty_buffer *b, *n;
> -	size_t left;
> -	bool change;
> +	struct tty_buffer *n, *b = buf->tail;
> +	size_t left = (b->flags ? 1 : 2) * b->size - b->used;

That's understandable?  Hah!

I'll take it, but ick, the original:

> +	bool change = !b->flags && flags;
>  
> -	b = buf->tail;
> -	if (!b->flags)
> -		left = 2 * b->size - b->used;
> -	else
> -		left = b->size - b->used;

Is much more readable.

Well kind of, it's all a mess :)

thanks,

greg k-h