net: dsa: microchip: ksz8795: Fix VLAN filtering

stable inclusion
from stable-5.10.60
commit dbfaf7a6a23a1fa06e83e3b7bec878ee85f5a5c6
bugzilla: 177018 https://gitee.com/openeuler/kernel/issues/I4EAUG

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=dbfaf7a6a23a1fa06e83e3b7bec878ee85f5a5c6



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[ Upstream commit 16484413 ]

Currently ksz8_port_vlan_filtering() sets or clears the VLAN Enable
hardware flag.  That controls discarding of packets with a VID that
has not been enabled for any port on the switch.

Since it is a global flag, set the dsa_switch::vlan_filtering_is_global
flag so that the DSA core understands this can't be controlled per
port.

When VLAN filtering is enabled, the switch should also discard packets
with a VID that's not enabled on the ingress port.  Set or clear each
external port's VLAN Ingress Filter flag in ksz8_port_vlan_filtering()
to make that happen.

Fixes: e66f840c ("net: dsa: ksz: Add Microchip KSZ8795 DSA driver")
Signed-off-by: Ben Hutchings <ben.hutchings@mind.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Acked-by: Weilong Chen <chenweilong@huawei.com>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>