From: Rafał Miłecki <rafal@milecki.pl> stable inclusion from linux-4.19.207 commit e24ffdb604179a057e9be5c9a8ed68b90a28eee5 -------------------------------- [ Upstream commit cdb067d31c0fe4cce98b9d15f1f2ef525acaa094 ] It isn't true that CPU port is always the last one. Switches BCM5301x have 9 ports (port 6 being inactive) and they use port 5 as CPU by default (depending on design some other may be CPU ports too). A more reliable way of determining number of ports is to check for the last set bit in the "enabled_ports" bitfield. This fixes b53 internal state, it will allow providing accurate info to the DSA and is required to fix BCM5301x support. Fixes: 967dd82ffc52 ("net: dsa: b53: Add support for Broadcom RoboSwitch") Signed-off-by: Rafał Miłecki <rafal@milecki.pl> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- drivers/net/dsa/b53/b53_common.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/net/dsa/b53/b53_common.c b/drivers/net/dsa/b53/b53_common.c index 7eaeab65d39f5..451121f47c89a 100644 --- a/drivers/net/dsa/b53/b53_common.c +++ b/drivers/net/dsa/b53/b53_common.c @@ -2135,9 +2135,8 @@ static int b53_switch_init(struct b53_device *dev) dev->cpu_port = 5; } - /* cpu port is always last */ - dev->num_ports = dev->cpu_port + 1; dev->enabled_ports |= BIT(dev->cpu_port); + dev->num_ports = fls(dev->enabled_ports); /* Include non standard CPU port built-in PHYs to be probed */ if (is539x(dev) || is531x5(dev)) { -- 2.25.1