linux-kernel - [PATCH 35/36] tty: hso: simplify hso_serial

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Message-ID: <20230810091510.13006-36-jirislaby@kernel.org>
Date:   Thu, 10 Aug 2023 11:15:09 +0200
From:   "Jiri Slaby (SUSE)" <jirislaby@...nel.org>
To:     gregkh@...uxfoundation.org
Cc:     linux-serial@...r.kernel.org, linux-kernel@...r.kernel.org,
        "Jiri Slaby (SUSE)" <jirislaby@...nel.org>,
        "David S. Miller" <davem@...emloft.net>,
        Eric Dumazet <edumazet@...gle.com>,
        Jakub Kicinski <kuba@...nel.org>,
        Paolo Abeni <pabeni@...hat.com>
Subject: [PATCH 35/36] tty: hso: simplify hso_serial_write()

There is no need for two more variables in hso_serial_write(). Switch to
min_t() and eliminate those.

Furthermore, the 'if-goto' is superfluous as memcpy() of zero count is a
nop. So is addition of zero. So remove the 'if-goto' completely.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@...nel.org>
Cc: "David S. Miller" <davem@...emloft.net>
Cc: Eric Dumazet <edumazet@...gle.com>
Cc: Jakub Kicinski <kuba@...nel.org>
Cc: Paolo Abeni <pabeni@...hat.com>
---
 drivers/net/usb/hso.c | 16 +++++-----------
 1 file changed, 5 insertions(+), 11 deletions(-)

diff --git a/drivers/net/usb/hso.c b/drivers/net/usb/hso.c
index 3f424da87bf4..83b8452220ec 100644
--- a/drivers/net/usb/hso.c
+++ b/drivers/net/usb/hso.c
@@ -1326,7 +1326,6 @@ static ssize_t hso_serial_write(struct tty_struct *tty, const u8 *buf,
 				size_t count)
 {
 	struct hso_serial *serial = tty->driver_data;
-	int space, tx_bytes;
 	unsigned long flags;
 
 	/* sanity check */
@@ -1337,21 +1336,16 @@ static ssize_t hso_serial_write(struct tty_struct *tty, const u8 *buf,
 
 	spin_lock_irqsave(&serial->serial_lock, flags);
 
-	space = serial->tx_data_length - serial->tx_buffer_count;
-	tx_bytes = (count < space) ? count : space;
+	count = min_t(size_t, serial->tx_data_length - serial->tx_buffer_count,
+		      count);
+	memcpy(serial->tx_buffer + serial->tx_buffer_count, buf, count);
+	serial->tx_buffer_count += count;
 
-	if (!tx_bytes)
-		goto out;
-
-	memcpy(serial->tx_buffer + serial->tx_buffer_count, buf, tx_bytes);
-	serial->tx_buffer_count += tx_bytes;
-
-out:
 	spin_unlock_irqrestore(&serial->serial_lock, flags);
 
 	hso_kick_transmit(serial);
 	/* done */
-	return tx_bytes;
+	return count;
 }
 
 /* how much room is there for writing */
-- 
2.41.0