[PATCH v1 net-next] net: dsa: Allow only up to two HSR HW offloaded ports for KSZ9477

[Lukasz Majewski]

The KSZ9477 allows HSR in-HW offloading for any of two selected ports.
This patch adds check if one tries to use more than two ports with
HSR offloading enabled.

Signed-off-by: Lukasz Majewski <lukma@xxxxxxx>
---
 drivers/net/dsa/microchip/ksz_common.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c
index 2818e24e2a51..0d68f0a5bf19 100644
--- a/drivers/net/dsa/microchip/ksz_common.c
+++ b/drivers/net/dsa/microchip/ksz_common.c
@@ -3913,6 +3913,9 @@ static int ksz_hsr_join(struct dsa_switch *ds, int port, struct net_device *hsr,
 	if (ret)
 		return ret;
 
+	if (dev->chip_id == KSZ9477_CHIP_ID && hweight8(dev->hsr_ports) > 1)
+		return -EOPNOTSUPP;
+
 	ksz9477_hsr_join(ds, port, hsr);
 	dev->hsr_dev = hsr;
 	dev->hsr_ports |= BIT(port);
-- 
2.20.1