[PATCH v2 14/14] tty: n_tty: deduplicate copy code in n_tty_receive_buf_real_raw()

From: Jiri Slaby (SUSE)
Date: Sun Aug 27 2023 - 03:44:40 EST


The code is duplicated to perform the copy twice -- to handle buffer
wrap-around. Instead of the duplication, roll this into the loop.

(And add some blank lines around to have the code a bit more readable.)

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@xxxxxxxxxx>
---
drivers/tty/n_tty.c | 25 ++++++++++++-------------
1 file changed, 12 insertions(+), 13 deletions(-)

diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index edf59f6fc669..6c9a408d67cd 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -1528,19 +1528,18 @@ n_tty_receive_buf_real_raw(const struct tty_struct *tty, const u8 *cp,
size_t count)
{
struct n_tty_data *ldata = tty->disc_data;
- size_t n, head;
-
- head = MASK(ldata->read_head);
- n = min(count, N_TTY_BUF_SIZE - head);
- memcpy(read_buf_addr(ldata, head), cp, n);
- ldata->read_head += n;
- cp += n;
- count -= n;
-
- head = MASK(ldata->read_head);
- n = min(count, N_TTY_BUF_SIZE - head);
- memcpy(read_buf_addr(ldata, head), cp, n);
- ldata->read_head += n;
+
+ /* handle buffer wrap-around by a loop */
+ for (unsigned int i = 0; i < 2; i++) {
+ size_t head = MASK(ldata->read_head);
+ size_t n = min(count, N_TTY_BUF_SIZE - head);
+
+ memcpy(read_buf_addr(ldata, head), cp, n);
+
+ ldata->read_head += n;
+ cp += n;
+ count -= n;
+ }
}

static void
--
2.42.0