The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 4a3e0aeddf091f00974b02627c157843ce382a24 Mon Sep 17 00:00:00 2001

From: Maarten Zanders maarten.zanders@mind.be Date: Mon, 11 Oct 2021 16:27:20 +0200 Subject: [PATCH] net: dsa: mv88e6xxx: don't use PHY_DETECT on internal PHY's

mv88e6xxx_port_ppu_updates() interpretes data in the PORT_STS register incorrectly for internal ports (ie no PPU). In these cases, the PHY_DETECT bit indicates link status. This results in forcing the MAC state whenever the PHY link goes down which is not intended. As a side effect, LED's configured to show link status stay lit even though the physical link is down.

Add a check in mac_link_down and mac_link_up to see if it concerns an external port and only then, look at PPU status.

Fixes: 5d5b231da7ac (net: dsa: mv88e6xxx: use PHY_DETECT in mac_link_up/mac_link_down) Reported-by: Maarten Zanders m.zanders@televic.com Reviewed-by: Maxime Chevallier maxime.chevallier@bootlin.com Signed-off-by: Maarten Zanders maarten.zanders@mind.be Signed-off-by: David S. Miller davem@davemloft.net

diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c index d7b29792732b..8dadcae93c9b 100644 --- a/drivers/net/dsa/mv88e6xxx/chip.c +++ b/drivers/net/dsa/mv88e6xxx/chip.c @@ -750,7 +750,11 @@ static void mv88e6xxx_mac_link_down(struct dsa_switch *ds, int port, ops = chip->info->ops;

mv88e6xxx_reg_lock(chip); - if ((!mv88e6xxx_port_ppu_updates(chip, port) || + /* Internal PHYs propagate their configuration directly to the MAC. + * External PHYs depend on whether the PPU is enabled for this port. + */ + if (((!mv88e6xxx_phy_is_internal(ds, port) && + !mv88e6xxx_port_ppu_updates(chip, port)) || mode == MLO_AN_FIXED) && ops->port_sync_link) err = ops->port_sync_link(chip, port, mode, false); mv88e6xxx_reg_unlock(chip); @@ -773,7 +777,12 @@ static void mv88e6xxx_mac_link_up(struct dsa_switch *ds, int port, ops = chip->info->ops;

mv88e6xxx_reg_lock(chip); - if (!mv88e6xxx_port_ppu_updates(chip, port) || mode == MLO_AN_FIXED) { + /* Internal PHYs propagate their configuration directly to the MAC. + * External PHYs depend on whether the PPU is enabled for this port. + */ + if ((!mv88e6xxx_phy_is_internal(ds, port) && + !mv88e6xxx_port_ppu_updates(chip, port)) || + mode == MLO_AN_FIXED) { /* FIXME: for an automedia port, should we force the link * down here - what if the link comes up due to "other" media * while we're bringing the port up, how is the exclusivity