Re: [PATCH] net: dsa: MxL862xx: don't force-enable MAXLINEAR_GPHY

[Guenter Roeck]

On 2/16/26 04:15, Daniel Golle wrote:
> On Mon, Feb 16, 2026 at 11:55:17AM +0100, Arnd Bergmann wrote:
> > From: Arnd Bergmann <arnd@xxxxxxxx>
> >
> > The newly added dsa driver attempts to enable the corresponding PHY driver,
> > but that one has additional dependencies that may not be available:
> >
> > WARNING: unmet direct dependencies detected for MAXLINEAR_GPHY
> >    Depends on [m]: NETDEVICES [=y] && PHYLIB [=y] && (HWMON [=m] || HWMON [=m]=n [=n])
> >    Selected by [y]:
> >    - NET_DSA_MXL862 [=y] && NETDEVICES [=y] && NET_DSA [=y]
> > aarch64-linux-ld: drivers/net/phy/mxl-gpy.o: in function `gpy_probe':
> > mxl-gpy.c:(.text.gpy_probe+0x13c): undefined reference to `devm_hwmon_device_register_with_info'
> > aarch64-linux-ld: drivers/net/phy/mxl-gpy.o: in function `gpy_hwmon_read':
> > mxl-gpy.c:(.text.gpy_hwmon_read+0x48): undefined reference to `polynomial_calc'
>
> I assume this happens in case CONFIG_MAXLINEAR_GPHY=y and
> CONFIG_HWMON=m, right?
>
> None of the PHY drivers seem to adequately prevent such situations,
> which in my opinion would be worth correcting, ie. by preventing any
> PHY driver using HWMON from being built-in while CONFIG_HWMON=m.

Technically, with "select MAXLINEAR_GPHY", NET_DSA_MXL862 should depend
on "depends on HWMON || HWMON=n". That would prevent NET_DSA_MXL862=y
and with it MAXLINEAR_GPHY=y.

Maybe it is time to implement dummy functions for hwmon API calls
to avoid all this.

Guenter

> > There is actually no compile-time dependency, as DSA correctly uses the
> > PHY abstractions. Remove the 'select' statement to reduce the complexity.
> >
> > Fixes: 23794bec1cb6 ("net: dsa: add basic initial driver for MxL862xx switches")
> > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
>
> As there is no compile-time dependency, this change is fine.
>
> Reviewed-by: Daniel Golle <daniel@xxxxxxxxxxxxxx>
>
> > ---
> >   drivers/net/dsa/mxl862xx/Kconfig | 1 -
> >   1 file changed, 1 deletion(-)
> >
> > diff --git a/drivers/net/dsa/mxl862xx/Kconfig b/drivers/net/dsa/mxl862xx/Kconfig
> > index 4db7bab21a71..3e772298cc89 100644
> > --- a/drivers/net/dsa/mxl862xx/Kconfig
> > +++ b/drivers/net/dsa/mxl862xx/Kconfig
> > @@ -2,7 +2,6 @@
> >   config NET_DSA_MXL862
> >   	tristate "MaxLinear MxL862xx"
> >   	depends on NET_DSA
> > -	select MAXLINEAR_GPHY
> >   	select NET_DSA_TAG_MXL_862XX
> >   	help
> >   	  This enables support for the MaxLinear MxL862xx switch family.
> > --
> > 2.39.5