From dcec8d291da8813b5e1c7c0967ae63463a8521f6 Mon Sep 17 00:00:00 2001 From: Lukasz Majewski Date: Wed, 19 Jun 2024 16:58:09 +0200 Subject: net: dsa: ksz_common: Allow only up to two HSR HW offloaded ports for KSZ9477 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. The problem is with RedBox configuration (HSR-SAN) - when configuring: ip link add name hsr0 type hsr slave1 lan1 slave2 lan2 interlink lan3 \ supervision 45 version 1 The lan1 (port0) and lan2 (port1) are correctly configured as ports, which can use HSR offloading on ksz9477. However, when we do already have two bits set in hsr_ports, we need to return (-ENOTSUPP), so the interlink port (lan3) would be used with SW based HSR RedBox support. Otherwise, I do see some strange network behavior, as some HSR frames are visible on non-HSR network and vice versa. This causes the switch connected to interlink port (lan3) to drop frames and no communication is possible. Moreover, conceptually - the interlink (i.e. HSR-SAN port - lan3/port2) shall be only supported in software as it is also possible to use ksz9477 with only SW based HSR (i.e. port0/1 -> hsr0 with offloading, port2 -> HSR-SAN/interlink, port4/5 -> hsr1 with SW based HSR). Fixes: 5055cccfc2d1 ("net: hsr: Provide RedBox support (HSR-SAN)") Signed-off-by: Lukasz Majewski Reviewed-by: Andrew Lunn Reviewed-by: Dan Carpenter Reviewed-by: Florian Fainelli Signed-off-by: David S. Miller --- drivers/net/dsa/microchip/ksz_common.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'drivers') diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c index 2818e24e2a51..debb554b60ed 100644 --- a/drivers/net/dsa/microchip/ksz_common.c +++ b/drivers/net/dsa/microchip/ksz_common.c @@ -3906,6 +3906,13 @@ static int ksz_hsr_join(struct dsa_switch *ds, int port, struct net_device *hsr, return -EOPNOTSUPP; } + /* KSZ9477 can only perform HSR offloading for up to two ports */ + if (hweight8(dev->hsr_ports) >= 2) { + NL_SET_ERR_MSG_MOD(extack, + "Cannot offload more than two ports - using software HSR"); + return -EOPNOTSUPP; + } + /* Self MAC address filtering, to avoid frames traversing * the HSR ring more than once. */ -- cgit v1.2.3