[PATCH net] net: dsa: microchip: Fix Wake-on-LAN check to not return an error

[PATCH net] net: dsa: microchip: Fix Wake-on-LAN check to not return an error

[Tristram.Ha]

From: Tristram Ha <tristram.ha@microchip.com>

The wol variable in ksz_port_set_mac_address() is declared with random
data, but the code in ksz_get_wol call may not be executed so the
WAKE_MAGIC check may be invalid resulting in an error message when
setting a MAC address after starting the DSA driver.

Fixes: 3b454b6390c3 ("net: dsa: microchip: ksz9477: Add Wake on Magic Packet support")
Signed-off-by: Tristram Ha <tristram.ha@microchip.com>
---
 drivers/net/dsa/microchip/ksz_common.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c
index b074b4bb0629..2725c5bc311c 100644
--- a/drivers/net/dsa/microchip/ksz_common.c
+++ b/drivers/net/dsa/microchip/ksz_common.c
@@ -3764,6 +3764,12 @@ static int ksz_port_set_mac_address(struct dsa_switch *ds, int port,
 		return -EBUSY;
 	}
 
+	/* Need to initialize variable as the code to fill in settings may
+	 * not be executed.
+	 */
+	wol.supported = 0;
+	wol.wolopts = 0;
+
 	ksz_get_wol(ds, dp->index, &wol);
 	if (wol.wolopts & WAKE_MAGIC) {
 		dev_err(ds->dev,
-- 
2.34.1

Re: [PATCH net] net: dsa: microchip: Fix Wake-on-LAN check to not return an error

[Oleksij Rempel]

On Thu, Aug 01, 2024 at 05:05:10PM -0700, Tristram.Ha@microchip.com wrote:
> From: Tristram Ha <tristram.ha@microchip.com>
> 
> The wol variable in ksz_port_set_mac_address() is declared with random
> data, but the code in ksz_get_wol call may not be executed so the
> WAKE_MAGIC check may be invalid resulting in an error message when
> setting a MAC address after starting the DSA driver.
> 
> Fixes: 3b454b6390c3 ("net: dsa: microchip: ksz9477: Add Wake on Magic Packet support")
> Signed-off-by: Tristram Ha <tristram.ha@microchip.com>
> ---
>  drivers/net/dsa/microchip/ksz_common.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c
> index b074b4bb0629..2725c5bc311c 100644
> --- a/drivers/net/dsa/microchip/ksz_common.c
> +++ b/drivers/net/dsa/microchip/ksz_common.c
> @@ -3764,6 +3764,12 @@ static int ksz_port_set_mac_address(struct dsa_switch *ds, int port,
>  		return -EBUSY;
>  	}
>  
> +	/* Need to initialize variable as the code to fill in settings may
> +	 * not be executed.
> +	 */
> +	wol.supported = 0;
> +	wol.wolopts = 0;
> +
>  	ksz_get_wol(ds, dp->index, &wol);
>  	if (wol.wolopts & WAKE_MAGIC) {
>  		dev_err(ds->dev,

Only wol.wolopts need to be cleared. wol.supported can be dropped.

With this change:
Reviewed-by: Oleksij Rempel <o.rempel@pengutronix.de>

Regards,
Oleksij
-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |