6.10-stable review patch. If anyone has any objections, please let me know.
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From: Lukasz Majewski lukma@denx.de
[ Upstream commit dcec8d291da8813b5e1c7c0967ae63463a8521f6 ]
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 lukma@denx.de Reviewed-by: Andrew Lunn andrew@lunn.ch Reviewed-by: Dan Carpenter dan.carpenter@linaro.org Reviewed-by: Florian Fainelli florian.fainelli@broadcom.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/dsa/microchip/ksz_common.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c index 0580b2fee21c3..baa1eeb9a1b04 100644 --- a/drivers/net/dsa/microchip/ksz_common.c +++ b/drivers/net/dsa/microchip/ksz_common.c @@ -3917,6 +3917,13 @@ 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. */