Re: CONFIG_NLS=m resulting in undefined reference toutf16s_to_utf8s causing build failure

From: Narendra_K
Date: Thu Jan 13 2011 - 11:47:38 EST


On Thu, Jan 13, 2011 at 08:53:55AM +0530, Len Brown wrote:
>
> > > drivers/built-in.o: In function `dsm_label_utf16s_to_utf8s':
> > > /usr/src/Linux-Next/linux-next/drivers/pci/pci-label.c:195: undefined reference to `utf16s_to_utf8s'
> > > make: *** [.tmp_vmlinux1] Error 1
> > >
> > > The drivers/pci/pci-label.c is compiled as part of vmlinux as defined by
> > > the makefile drivers/pci/Makefile.
> > >
> > > #
> > > # ACPI Related PCI FW Functions
> > > # ACPI _DSM provided firmware instance and string name
> > > #
> > > obj-$(CONFIG_ACPI) += pci-acpi.o pci-label.o
> > >
> > > # SMBIOS provided firmware instance and labels
> > > obj-$(CONFIG_DMI) += pci-label.o
> > >
> > > This could be prevented by one of the following methods -
> > >
> > > * forcing CONFIG_NLS=y if CONFIG_PCI=y
> > > * move `utf16s_to_utf8s' out of nls_base.c to a new file to be always
> > > built into vmlinux
> > >
> > > Please correct me if i missed something here and let me know what would be the right
> > > way to fix this build failure.
> >
> > So there's no other ACPI code that depends on this function? I'd hate
> > to make PCI depend on NLS, so assuming ACPI doesn't need it (in which
> > case the select or depend should be there), I guess it should be pulled
> > into a common file that will always be included.
>
> No, nothing in the ACPI code uses utf16s_to_utf8s.

Len,

Thanks for the information.

>
> I don't know anything about NLS, but it appears to be
> something that file systems (befs, cifs, fat, hfs, isofs, jfs, etc)
> use to to support native languages.
>
> BTW. I don't understand why pci-label.o appears twice above.
> It used to be just the 2nd one, that depends on CONFIG_DMI.
>

Support has been added to export ACPI _DSM provided firmware instance
number and string, defined in 'PCI Firmware Specification Revision 3.1'
section 4.6.7.( DSM for Naming a PCI or PCI Express Device Under
Operating Systems) to sysfs. So we need to compile pci-labe.c if either
of CONFIG_DMI or CONFIG_ACPI is set. When ACPI _DSM is available it
takes priority.

With regards,
Narendra K --
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