[PATCH 5.11 279/601] serial: core: return early on unsupported ioctls

[Greg Kroah-Hartman]

From: Johan Hovold <johan@xxxxxxxxxx>

[ Upstream commit 79c5966cec7b148199386ef9933c31b999379065 ]

Drivers can return -ENOIOCTLCMD when an ioctl is not recognised to tell
the upper layers to continue looking for a handler.

This is not the case for the RS485 and ISO7816 ioctls whose handlers
should return -ENOTTY directly in case a serial driver does not
implement the corresponding methods.

Fixes: a5f276f10ff7 ("serial_core: Handle TIOC[GS]RS485 ioctls.")
Fixes: ad8c0eaa0a41 ("tty/serial_core: add ISO7816 infrastructure")
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20210407095208.31838-9-johan@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/tty/serial/serial_core.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 828f9ad1be49..c6cbaccc19b0 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -1306,7 +1306,7 @@ static int uart_set_rs485_config(struct uart_port *port,
 	unsigned long flags;
 
 	if (!port->rs485_config)
-		return -ENOIOCTLCMD;
+		return -ENOTTY;
 
 	if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user)))
 		return -EFAULT;
@@ -1330,7 +1330,7 @@ static int uart_get_iso7816_config(struct uart_port *port,
 	struct serial_iso7816 aux;
 
 	if (!port->iso7816_config)
-		return -ENOIOCTLCMD;
+		return -ENOTTY;
 
 	spin_lock_irqsave(&port->lock, flags);
 	aux = port->iso7816;
@@ -1350,7 +1350,7 @@ static int uart_set_iso7816_config(struct uart_port *port,
 	unsigned long flags;
 
 	if (!port->iso7816_config)
-		return -ENOIOCTLCMD;
+		return -ENOTTY;
 
 	if (copy_from_user(&iso7816, iso7816_user, sizeof(*iso7816_user)))
 		return -EFAULT;
-- 
2.30.2