Messages in this thread | | | Date | Wed, 2 Jun 2021 00:21:58 +0200 | From | Andrew Lunn <> | Subject | Re: [RFC net-next 0/2] Introduce MDIO probe order C45 over C22 |
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On Tue, Jun 01, 2021 at 11:44:23PM +0800, Wong Vee Khee wrote: > On Tue, Jun 01, 2021 at 03:04:51PM +0200, Andrew Lunn wrote: > > On Tue, Jun 01, 2021 at 06:47:34PM +0800, Wong Vee Khee wrote: > > > On Tue, May 25, 2021 at 03:34:34PM +0200, Andrew Lunn wrote: > > > > On Tue, May 25, 2021 at 01:58:03PM +0800, Wong Vee Khee wrote: > > > > > Synopsys MAC controller is capable of pairing with external PHY devices > > > > > that accessible via Clause-22 and Clause-45. > > > > > > > > > > There is a problem when it is paired with Marvell 88E2110 which returns > > > > > PHY ID of 0 using get_phy_c22_id(). We can add this check in that > > > > > function, but this will break swphy, as swphy_reg_reg() return 0. [1] > > > > > > > > Is it possible to identify it is a Marvell PHY? Do any of the other > > > > C22 registers return anything unique? I'm wondering if adding > > > > .match_phy_device to genphy would work to identify it is a Marvell PHY > > > > and not bind to it. Or we can turn it around, make the > > > > .match_phy_device specifically look for the fixed-link device by > > > > putting a magic number in one of the vendor registers. > > > > > > > > > > I checked the Marvell and did not see any unique register values. > > > Also, since get_phy_c22_id() returns a *phy_id== 0, it is not bind to > > > any PHY driver, so I don't think adding the match_phy_device check in > > > getphy would help. > > > > It has a Marvell ID in C45 space. So maybe we need to special case for > > ID 0. If we get that, go look in C45 space. If we find a valid ID, use > > it. If we get EOPNOTSUP because the MDIO bus is not C45 capable, or we > > don't find a vendor ID in C45 space, keep with id == 0 and load > > genphy? > > > > Make sense for me. > Let me what you think of adding the checks in *get_phy_device(): > > diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c > index 1539ea021ac0..ad9a87fadea1 100644 > --- a/drivers/net/phy/phy_device.c > +++ b/drivers/net/phy/phy_device.c > @@ -862,11 +862,21 @@ struct phy_device *get_phy_device(struct mii_bus *bus, int addr, bool is_c45) > c45_ids.mmds_present = 0; > memset(c45_ids.device_ids, 0xff, sizeof(c45_ids.device_ids)); > > - if (is_c45) > + if (is_c45) { > r = get_phy_c45_ids(bus, addr, &c45_ids); > - else > + } else { > r = get_phy_c22_id(bus, addr, &phy_id); > > + if (phy_id == 0) { > + r = get_phy_c45_ids(bus, addr, &c45_ids); > + if (r == -ENOTSUPP || r == -ENODEV) > + return 0;
This bit is not correct. I said 'or we don't find a vendor ID in C45 space, keep with id == 0'. We need to keep backwards compatibility. If get_phy_c22_id() did not return an error we should create a device with phy_id 0, if get_phy_c45_ids() returns an error.
Andrew
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