BUG: "13d0ab6750b2 net: phy: check return code when requesting PHY driver module" breaks NFS-Root

BUG: "13d0ab6750b2 net: phy: check return code when requesting PHY driver module" breaks NFS-Root

[Marc Kleine-Budde]

[-- Attachment #1.1: Type: text/plain, Size: 1565 bytes --]

Hello,

I'm on next-next/master and noticed that the following patch:

| 13d0ab6750b2 net: phy: check return code when requesting PHY
|              driver module

breaks NFS Root for my embedded device (riotboard). The kernel dhcp
fails to get an address and thus no NFS Root.

> [    1.869897] mdio_bus 2188000.ethernet-1:04: error -2 loading PHY driver module for ID 0x004dd072

The PHY driver is not compiled as a module, but compiled into the kernel:

> git grep 0x004dd072 drivers/net/phy/
> drivers/net/phy/at803x.c:#define ATH8035_PHY_ID 0x004dd072

> grep AT803 .config
> CONFIG_AT803X_PHY=y

After hacking the return value check away, the system boots again.

> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
> index ddb12f420940..49c8aa7c7c03 100644
> --- a/drivers/net/phy/phy_device.c
> +++ b/drivers/net/phy/phy_device.c
> @@ -558,7 +558,7 @@ static int phy_request_driver_module(struct phy_device *dev, int phy_id)
>         if (IS_ENABLED(CONFIG_MODULES) && ret < 0) {
>                 phydev_err(dev, "error %d loading PHY driver module for ID 0x%08x\n",
>                            ret, phy_id);
> -               return ret;
> +               return 0;
>         }
> 
>         return 0;

regards,
Marc

-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
Industrial Linux Solutions        | Phone: +49-231-2826-924     |
Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

Re: BUG: "13d0ab6750b2 net: phy: check return code when requesting PHY driver module" breaks NFS-Root

[Marc Kleine-Budde]

[-- Attachment #1.1: Type: text/plain, Size: 969 bytes --]

On 3/11/19 1:23 PM, Marc Kleine-Budde wrote:
> Hello,
> 
> I'm on next-next/master and noticed that the following patch:
> 
> | 13d0ab6750b2 net: phy: check return code when requesting PHY
> |              driver module
> 
> breaks NFS Root for my embedded device (riotboard). The kernel dhcp
> fails to get an address and thus no NFS Root.

Just noticed that problem was fixed by commit:

| 21e194425abd net: phy: fix issue with loading PHY driver w/o initramfs

I continued bisecting and found a bad commit in the riotboard's phy
driver. I'll send a separate mail for this.

| cd28d1d6e52e net: phy: at803x: Disable phy delay for RGMII mode

Sorry for the noise,
Marc

-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
Industrial Linux Solutions        | Phone: +49-231-2826-924     |
Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

Re: BUG: "13d0ab6750b2 net: phy: check return code when requesting PHY driver module" breaks NFS-Root

[Florian Fainelli]

On 3/11/19 11:04 AM, Marc Kleine-Budde wrote:
> On 3/11/19 1:23 PM, Marc Kleine-Budde wrote:
>> Hello,
>>
>> I'm on next-next/master and noticed that the following patch:
>>
>> | 13d0ab6750b2 net: phy: check return code when requesting PHY
>> |              driver module
>>
>> breaks NFS Root for my embedded device (riotboard). The kernel dhcp
>> fails to get an address and thus no NFS Root.
> 
> Just noticed that problem was fixed by commit:
> 
> | 21e194425abd net: phy: fix issue with loading PHY driver w/o initramfs
> 
> I continued bisecting and found a bad commit in the riotboard's phy
> driver. I'll send a separate mail for this.
> 
> | cd28d1d6e52e net: phy: at803x: Disable phy delay for RGMII mode

If your problem is with this driver, keep in mind that the at803x PHY
driver incorrectly acted on the 'phy-mode'/phy_interface_t type and you
may need DTS changes to be conforming. Of course, there is no way to
programmatically detect any of that, which adds to the fun.
-- 
Florian

Re: BUG: "13d0ab6750b2 net: phy: check return code when requesting PHY driver module" breaks NFS-Root

[Marc Kleine-Budde]

[-- Attachment #1.1: Type: text/plain, Size: 981 bytes --]

On 3/11/19 7:11 PM, Florian Fainelli wrote:
>> I continued bisecting and found a bad commit in the riotboard's phy
>> driver. I'll send a separate mail for this.
>>
>> | cd28d1d6e52e net: phy: at803x: Disable phy delay for RGMII mode
> 
> If your problem is with this driver, keep in mind that the at803x PHY
> driver incorrectly acted on the 'phy-mode'/phy_interface_t type and you
> may need DTS changes to be conforming. Of course, there is no way to
> programmatically detect any of that, which adds to the fun.

Thanks for the tip, that was the problem. Changing the phy-mode to
rgmii-id restores the old behaviour in the driver and the board boots again.

I'll send a patch.

Marc

-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
Industrial Linux Solutions        | Phone: +49-231-2826-924     |
Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 488 bytes --]