On Mon, Feb 15, 2021 at 04:16:27PM +0100, Marek Behun wrote: > On Mon, 15 Feb 2021 14:57:57 +0000 > Russell King - ARM Linux admin <li...@armlinux.org.uk> wrote: > > > On Mon, Feb 15, 2021 at 02:47:56PM +0100, Marek Behun wrote: > > > On Mon, 15 Feb 2021 06:15:59 +0000 > > > Nathan Rossi <nat...@nathanrossi.com> wrote: > > > > > > > diff --git a/drivers/net/dsa/mv88e6xxx/chip.c > > > > b/drivers/net/dsa/mv88e6xxx/chip.c > > > > index 54aa942eed..5c52906b29 100644 > > > > --- a/drivers/net/dsa/mv88e6xxx/chip.c > > > > +++ b/drivers/net/dsa/mv88e6xxx/chip.c > > > > @@ -650,6 +650,13 @@ static void mv88e6xxx_validate(struct dsa_switch > > > > *ds, int port, > > > > if (chip->info->ops->phylink_validate) > > > > chip->info->ops->phylink_validate(chip, port, mask, > > > > state); > > > > > > > > + /* Advertise 2500BASEX only if 1000BASEX is not configured, this > > > > + * prevents phylink_helper_basex_speed from always overriding > > > > the > > > > + * 1000BASEX mode since auto negotiation is always enabled. > > > > + */ > > > > + if (state->interface == PHY_INTERFACE_MODE_1000BASEX) > > > > + phylink_clear(mask, 2500baseX_Full); > > > > + > > > > > > I don't quite like this. This problem should be either solved in > > > phylink_helper_basex_speed() or somewhere in the mv88e6xxx code, but near > > > the call to phylink_helper_basex_speed(). > > > > > > Putting a solution to the behaviour of phylink_helper_basex_speed() it > > > into the validate() method when phylink_helper_basex_speed() is called > > > from a different place will complicate debugging in the future. If > > > we start solving problems in this kind of way, the driver will become > > > totally unreadable, IMO. > > > > If we can't switch between 1000base-X and 2500base-X, then we should > > not be calling phylink_helper_basex_speed() - and only one of those > > two capabilities should be set in the validation callback. I thought > > there were DSA switches where we could program the CMODE to switch > > between these two... > > There are. At least Peridot, Topaz and Amethyst support switching > between these modes. But only on some ports. > > This problem happnes on Peridot X, I think. > > On Peridot X there are > - port 0: RGMII > - ports 9-10: capable of 1, 2.5 and 10G SerDes (10G via > XAUI/RXAUI, so multiple lanes) > - ports 1-8: with copper PHYs > - some of these can instead be set to use the unused SerDes lanes > of ports 9-10, but only in 1000base-x mode > > So the problem can happen if you set port 9 or 10 to only use one > SerDes lane, and use the spare lanes for the 1G ports. > On these ports 2500base-x is not supported, only 1000base-x (maybe > sgmii, I don't remember)
It sounds like the modes are not reporting correctly then before calling phylink_helper_basex_speed(). If the port can only be used at 1000base-X, then it should not be allowing 2500base-X to be set prior to calling phylink_helper_basex_speed(). -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!
