Messages in this thread Patch in this message | | | Date | Wed, 2 Jun 2021 22:15:57 +0800 | From | Wong Vee Khee <> | Subject | Re: [RFC net-next 0/2] Introduce MDIO probe order C45 over C22 |
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On Wed, Jun 02, 2021 at 04:19:43AM +0200, Andrew Lunn wrote: > > Yeah, you're right. Thanks for pointing that out. It should be: > > > > diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c > > index 1539ea021ac0..73bfde770f2d 100644 > > --- a/drivers/net/phy/phy_device.c > > +++ b/drivers/net/phy/phy_device.c > > @@ -862,11 +862,22 @@ 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 phy_device_create(bus, addr, phy_id, > > + false, &c45_ids); > > + else > > + return phy_device_create(bus, addr, phy_id, > > + true, &c45_ids); > > Still not correct. Think about when get_phy_c22_id() returns an > error. Walk through all the different code paths and check they do the > right thing. It is actually a lot more complex than what is shown > here. Think about all the different types of PHYs and all the > different types of MDIO bus drivers. >
I took a look at how most ethernet drivers implement their "bus->read" function. Most of them either return -EIO or -ENODEV.
I think it safe to drop the return error type when we try with C45 access:
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c index 1539ea021ac0..282d16fdf6e1 100644 --- a/drivers/net/phy/phy_device.c +++ b/drivers/net/phy/phy_device.c @@ -870,6 +870,18 @@ struct phy_device *get_phy_device(struct mii_bus *bus, int addr, bool is_c45) if (r) return ERR_PTR(r);
+ /* PHY device such as the Marvell Alaska 88E2110 will return a PHY ID + * of 0 when probed using get_phy_c22_id() with no error. Proceed to + * probe with C45 to see if we're able to get a valid PHY ID in the C45 + * space, if successful, create the C45 PHY device. + */ + if ((!is_c45) && (phy_id == 0)) { + r = get_phy_c45_ids(bus, addr, &c45_ids); + if (!r) + return phy_device_create(bus, addr, phy_id, + true, &c45_ids); + } + return phy_device_create(bus, addr, phy_id, is_c45, &c45_ids); } EXPORT_SYMBOL(get_phy_device); With this implementation, it should have handled all four scenarios listed in the table below:
*------------------*------------*------------* | get_phy_c22_id() | phy_id==0 | Handled | | return error | | | *------------------*------------*------------* | false | false | true | *------------------*------------*------------* | false | true | true | *------------------*------------*------------* | true | false | true | *------------------*------------*------------* | true | true | true | *------------------*------------*------------*
VK
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