This is a note to let you know that I've just added the patch titled net: dsa: mv88e6xxx: allow use of PHYs on CPU and DSA ports to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-dsa-mv88e6xxx-allow-use-of-phys-on-cpu-and-dsa-ports.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 04ec4e6250e5f58b525b08f3dca45c7d7427620e Mon Sep 17 00:00:00 2001 From: "Russell King (Oracle)" <rmk+kernel@xxxxxxxxxxxxxxx> Date: Thu, 9 Dec 2021 09:26:47 +0000 Subject: net: dsa: mv88e6xxx: allow use of PHYs on CPU and DSA ports From: Russell King (Oracle) <rmk+kernel@xxxxxxxxxxxxxxx> commit 04ec4e6250e5f58b525b08f3dca45c7d7427620e upstream. Martyn Welch reports that his CPU port is unable to link where it has been necessary to use one of the switch ports with an internal PHY for the CPU port. The reason behind this is the port control register is left forcing the link down, preventing traffic flow. This occurs because during initialisation, phylink expects the link to be down, and DSA forces the link down by synthesising a call to the DSA drivers phylink_mac_link_down() method, but we don't touch the forced-link state when we later reconfigure the port. Resolve this by also unforcing the link state when we are operating in PHY mode and the PPU is set to poll the PHY to retrieve link status information. Reported-by: Martyn Welch <martyn.welch@xxxxxxxxxxxxx> Tested-by: Martyn Welch <martyn.welch@xxxxxxxxxxxxx> Fixes: 3be98b2d5fbc ("net: dsa: Down cpu/dsa ports phylink will control") Cc: <stable@xxxxxxxxxxxxxxx> # 5.7: 2b29cb9e3f7f: net: dsa: mv88e6xxx: fix "don't use PHY_DETECT on internal PHY's" Signed-off-by: Russell King (Oracle) <rmk+kernel@xxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/E1mvFhP-00F8Zb-Ul@xxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/dsa/mv88e6xxx/chip.c | 66 ++++++++++++++++++++------------------- 1 file changed, 35 insertions(+), 31 deletions(-) --- a/drivers/net/dsa/mv88e6xxx/chip.c +++ b/drivers/net/dsa/mv88e6xxx/chip.c @@ -666,44 +666,48 @@ static void mv88e6xxx_mac_config(struct { struct mv88e6xxx_chip *chip = ds->priv; struct mv88e6xxx_port *p; - int err; + int err = 0; p = &chip->ports[port]; - /* FIXME: is this the correct test? If we're in fixed mode on an - * internal port, why should we process this any different from - * PHY mode? On the other hand, the port may be automedia between - * an internal PHY and the serdes... - */ - if ((mode == MLO_AN_PHY) && mv88e6xxx_phy_is_internal(ds, port)) - return; - mv88e6xxx_reg_lock(chip); - /* In inband mode, the link may come up at any time while the link - * is not forced down. Force the link down while we reconfigure the - * interface mode. - */ - if (mode == MLO_AN_INBAND && p->interface != state->interface && - chip->info->ops->port_set_link) - chip->info->ops->port_set_link(chip, port, LINK_FORCED_DOWN); - - err = mv88e6xxx_port_config_interface(chip, port, state->interface); - if (err && err != -EOPNOTSUPP) - goto err_unlock; - - err = mv88e6xxx_serdes_pcs_config(chip, port, mode, state->interface, - state->advertising); - /* FIXME: we should restart negotiation if something changed - which - * is something we get if we convert to using phylinks PCS operations. - */ - if (err > 0) - err = 0; + + if (mode != MLO_AN_PHY || !mv88e6xxx_phy_is_internal(ds, port)) { + /* In inband mode, the link may come up at any time while the + * link is not forced down. Force the link down while we + * reconfigure the interface mode. + */ + if (mode == MLO_AN_INBAND && + p->interface != state->interface && + chip->info->ops->port_set_link) + chip->info->ops->port_set_link(chip, port, + LINK_FORCED_DOWN); + + err = mv88e6xxx_port_config_interface(chip, port, + state->interface); + if (err && err != -EOPNOTSUPP) + goto err_unlock; + + err = mv88e6xxx_serdes_pcs_config(chip, port, mode, + state->interface, + state->advertising); + /* FIXME: we should restart negotiation if something changed - + * which is something we get if we convert to using phylinks + * PCS operations. + */ + if (err > 0) + err = 0; + } /* Undo the forced down state above after completing configuration - * irrespective of its state on entry, which allows the link to come up. + * irrespective of its state on entry, which allows the link to come + * up in the in-band case where there is no separate SERDES. Also + * ensure that the link can come up if the PPU is in use and we are + * in PHY mode (we treat the PPU as an effective in-band mechanism.) */ - if (mode == MLO_AN_INBAND && p->interface != state->interface && - chip->info->ops->port_set_link) + if (chip->info->ops->port_set_link && + ((mode == MLO_AN_INBAND && p->interface != state->interface) || + (mode == MLO_AN_PHY && mv88e6xxx_port_ppu_updates(chip, port)))) chip->info->ops->port_set_link(chip, port, LINK_UNFORCED); p->interface = state->interface; Patches currently in stable-queue which might be from rmk+kernel@xxxxxxxxxxxxxxx are queue-5.10/net-dsa-mv88e6xxx-allow-use-of-phys-on-cpu-and-dsa-ports.patch