linux-kernel - [PATCH 5.12 016/677] tty: mxser: fix TIOCSSERIAL jiffies conversions

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Date:   Wed, 12 May 2021 16:41:02 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Johan Hovold <johan@...nel.org>
Subject: [PATCH 5.12 016/677] tty: mxser: fix TIOCSSERIAL jiffies conversions

From: Johan Hovold <johan@...nel.org>

commit be6cf583d24dfe87324dd2830d90fc056e0a6648 upstream.

The port close_delay and closing wait parameters set by TIOCSSERIAL are
specified in jiffies, while the values returned by TIOCGSERIAL are
specified in centiseconds.

Add the missing conversions so that TIOCSSERIAL works as expected also
when HZ is not 100.

Cc: stable@...r.kernel.org
Signed-off-by: Johan Hovold <johan@...nel.org>
Link: https://lore.kernel.org/r/20210407102334.32361-14-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 drivers/tty/mxser.c |   24 ++++++++++++++++++------
 1 file changed, 18 insertions(+), 6 deletions(-)

--- a/drivers/tty/mxser.c
+++ b/drivers/tty/mxser.c
@@ -1208,19 +1208,26 @@ static int mxser_get_serial_info(struct
 {
 	struct mxser_port *info = tty->driver_data;
 	struct tty_port *port = &info->port;
+	unsigned int closing_wait, close_delay;
 
 	if (tty->index == MXSER_PORTS)
 		return -ENOTTY;
 
 	mutex_lock(&port->mutex);
+
+	close_delay = jiffies_to_msecs(info->port.close_delay) / 10;
+	closing_wait = info->port.closing_wait;
+	if (closing_wait != ASYNC_CLOSING_WAIT_NONE)
+		closing_wait = jiffies_to_msecs(closing_wait) / 10;
+
 	ss->type = info->type,
 	ss->line = tty->index,
 	ss->port = info->ioaddr,
 	ss->irq = info->board->irq,
 	ss->flags = info->port.flags,
 	ss->baud_base = info->baud_base,
-	ss->close_delay = info->port.close_delay,
-	ss->closing_wait = info->port.closing_wait,
+	ss->close_delay = close_delay;
+	ss->closing_wait = closing_wait;
 	ss->custom_divisor = info->custom_divisor,
 	mutex_unlock(&port->mutex);
 	return 0;
@@ -1233,7 +1240,7 @@ static int mxser_set_serial_info(struct
 	struct tty_port *port = &info->port;
 	speed_t baud;
 	unsigned long sl_flags;
-	unsigned int flags;
+	unsigned int flags, close_delay, closing_wait;
 	int retval = 0;
 
 	if (tty->index == MXSER_PORTS)
@@ -1255,9 +1262,14 @@ static int mxser_set_serial_info(struct
 
 	flags = port->flags & ASYNC_SPD_MASK;
 
+	close_delay = msecs_to_jiffies(ss->close_delay * 10);
+	closing_wait = ss->closing_wait;
+	if (closing_wait != ASYNC_CLOSING_WAIT_NONE)
+		closing_wait = msecs_to_jiffies(closing_wait * 10);
+
 	if (!capable(CAP_SYS_ADMIN)) {
 		if ((ss->baud_base != info->baud_base) ||
-				(ss->close_delay != info->port.close_delay) ||
+				(close_delay != info->port.close_delay) ||
 				((ss->flags & ~ASYNC_USR_MASK) != (info->port.flags & ~ASYNC_USR_MASK))) {
 			mutex_unlock(&port->mutex);
 			return -EPERM;
@@ -1271,8 +1283,8 @@ static int mxser_set_serial_info(struct
 		 */
 		port->flags = ((port->flags & ~ASYNC_FLAGS) |
 				(ss->flags & ASYNC_FLAGS));
-		port->close_delay = ss->close_delay * HZ / 100;
-		port->closing_wait = ss->closing_wait * HZ / 100;
+		port->close_delay = close_delay;
+		port->closing_wait = closing_wait;
 		if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST &&
 				(ss->baud_base != info->baud_base ||
 				ss->custom_divisor !=