[PATCH net-next v4 09/14] net: dsa: b53: prevent DIS_LEARNING access on BCM5325

["Álvaro Fernández Rojas" <noltari@gmail.com>]

BCM5325 doesn't implement DIS_LEARNING register so we should avoid reading
or writing it.

Fixes: f9b3827ee66c ("net: dsa: b53: Support setting learning on port")
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
---
 drivers/net/dsa/b53/b53_common.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

 v4: no changes

 v3: no changes

 v2: add changes proposed by Vladimir:
  - Disallow BR_LEARNING on b53_br_flags_pre() for BCM5325.

diff --git a/drivers/net/dsa/b53/b53_common.c b/drivers/net/dsa/b53/b53_common.c
index c7c950127448..daf7c1906711 100644
--- a/drivers/net/dsa/b53/b53_common.c
+++ b/drivers/net/dsa/b53/b53_common.c
@@ -593,6 +593,9 @@ static void b53_port_set_learning(struct b53_device *dev, int port,
 {
 	u16 reg;
 
+	if (is5325(dev))
+		return;
+
 	b53_read16(dev, B53_CTRL_PAGE, B53_DIS_LEARNING, &reg);
 	if (learning)
 		reg &= ~BIT(port);
@@ -2243,7 +2246,13 @@ int b53_br_flags_pre(struct dsa_switch *ds, int port,
 		     struct switchdev_brport_flags flags,
 		     struct netlink_ext_ack *extack)
 {
-	if (flags.mask & ~(BR_FLOOD | BR_MCAST_FLOOD | BR_LEARNING))
+	struct b53_device *dev = ds->priv;
+	unsigned long mask = (BR_FLOOD | BR_MCAST_FLOOD);
+
+	if (!is5325(dev))
+		mask |= BR_LEARNING;
+
+	if (flags.mask & ~mask)
 		return -EINVAL;
 
 	return 0;
-- 
2.39.5