[PATCH 5.14 109/151] net: dsa: mv88e6xxx: dont use PHY_DETECT on internal PHYs

Greg Kroah-Hartman
2021-10-18T14:03:34Z

From: Maarten Zanders <maarten.zanders@mind.be>

commit 4a3e0aeddf091f00974b02627c157843ce382a24 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/dsa/mv88e6xxx/chip.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)

--- a/drivers/net/dsa/mv88e6xxx/chip.c
+++ b/drivers/net/dsa/mv88e6xxx/chip.c
@@ -749,7 +749,11 @@ static void mv88e6xxx_mac_link_down(stru
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);
@@ -772,7 +776,12 @@ static void mv88e6xxx_mac_link_up(struct
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