Re: [PATCH] s390/net: lcs: fix build errors when FDDI is a loadable module

[Christian Borntraeger]

Am 22.06.23 um 14:16 schrieb Alexandra Winter:
> On 22.06.23 09:53, Simon Horman wrote:
> > On Thu, Jun 22, 2023 at 09:15:24AM +0200, Alexandra Winter wrote:
> > > On 21.06.23 23:37, Randy Dunlap wrote:
> > > > Require FDDI to be built-in if it is used. LCS needs FDDI to be
> > > > built-in to build without errors.
> > > >
> > > > Prevents these build errors:
> > > > s390-linux-ld: drivers/s390/net/lcs.o: in function `lcs_new_device':
> > > > drivers/s390/net/lcs.c:2150: undefined reference to `fddi_type_trans'
> > > > s390-linux-ld: drivers/s390/net/lcs.c:2151: undefined reference to `alloc_fddidev'
> > > >
> > > > This FDDI requirement effectively restores the previous condition
> > > > before the blamed patch, when #ifdef CONFIG_FDDI was used, without
> > > > testing for CONFIG_FDDI_MODULE.
> > > >
> > > > Fixes: 128272336120 ("s390/net: lcs: use IS_ENABLED() for kconfig detection")
> [...]
> > > 2) I wonder whether
> > >
> > >    	depends on CCW && NETDEVICES && (ETHERNET || FDDI)
> > >   +	depends on FDDI || FDDI=n
> > >
> > > would do what we want here:
> > > When FDDI is a loadable module, LCS mustn't be built-in.
> > >
> > > I will do some experiments and let you know.
> >
> > It does seem to on my side.
> > But checking would be much appreciated.
>   
>
> Here are my experiments:

Another suggestion. Why not remove the FDDI part of the lcs driver? This seems unused
without hardware for years now.Longterm we could even remove the whole lcs driver.