[PATCH net, v2] of_mdio: avoid MDIO bus removal when a PHY is missing

[PATCH net, v2] of_mdio: avoid MDIO bus removal when a PHY is missing

[Madalin Bucur]

If one of the child devices is missing the of_mdiobus_register_phy()
call will return -ENODEV. When a missing device is encountered the
registration of the remaining PHYs is stopped and the MDIO bus will
fail to register. Propagate all errors except ENODEV to avoid it.

Signed-off-by: Madalin Bucur <madalin.bucur@nxp.com>
---
v2: add an error print for the first change; the second place has
    some noise aleady generated by the exing code

 drivers/of/of_mdio.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/of/of_mdio.c b/drivers/of/of_mdio.c
index 3481e69..a249370 100644
--- a/drivers/of/of_mdio.c
+++ b/drivers/of/of_mdio.c
@@ -231,8 +231,14 @@ int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np)
 			rc = of_mdiobus_register_phy(mdio, child, addr);
 		else
 			rc = of_mdiobus_register_device(mdio, child, addr);
-		if (rc)
-			goto unregister;
+
+		if (rc == -ENODEV)
+			dev_err(&mdio->dev,
+				"MDIO device at address %d is missing.\n",
+				addr);
+		else
+			if (rc)
+				goto unregister;
 	}
 
 	if (!scanphys)
@@ -255,7 +261,7 @@ int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np)
 
 			if (of_mdiobus_child_is_phy(child)) {
 				rc = of_mdiobus_register_phy(mdio, child, addr);
-				if (rc)
+				if (rc && rc != -ENODEV)
 					goto unregister;
 			}
 		}
-- 
2.1.0

Re: [PATCH net, v2] of_mdio: avoid MDIO bus removal when a PHY is missing

[Geert Uytterhoeven]

Hi Madalin,

On Tue, Jan 9, 2018 at 9:33 AM, Madalin Bucur <madalin.bucur@nxp.com> wrote:
> If one of the child devices is missing the of_mdiobus_register_phy()
> call will return -ENODEV. When a missing device is encountered the
> registration of the remaining PHYs is stopped and the MDIO bus will
> fail to register. Propagate all errors except ENODEV to avoid it.
>
> Signed-off-by: Madalin Bucur <madalin.bucur@nxp.com>

Thanks for your patch!

> ---
> v2: add an error print for the first change; the second place has
>     some noise aleady generated by the exing code
>
>  drivers/of/of_mdio.c | 12 +++++++++---
>  1 file changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/of/of_mdio.c b/drivers/of/of_mdio.c
> index 3481e69..a249370 100644
> --- a/drivers/of/of_mdio.c
> +++ b/drivers/of/of_mdio.c
> @@ -231,8 +231,14 @@ int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np)
>                         rc = of_mdiobus_register_phy(mdio, child, addr);
>                 else
>                         rc = of_mdiobus_register_device(mdio, child, addr);
> -               if (rc)
> -                       goto unregister;
> +
> +               if (rc == -ENODEV)
> +                       dev_err(&mdio->dev,
> +                               "MDIO device at address %d is missing.\n",
> +                               addr);
> +               else
> +                       if (rc)

You can merge the two lines above into a single line.

> +                               goto unregister;

... dropping the need to reindent the above line.

>         }

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds