Re: [PATCH 03/19] LoongArch: Add build infrastructure

[Huacai Chen <chenhuacai@gmail.com>]

Hi, Arnd,

On Mon, Jul 19, 2021 at 3:43 PM Arnd Bergmann <arnd@kernel.org> wrote:
>
> On Mon, Jul 19, 2021 at 3:26 AM Huacai Chen <chenhuacai@gmail.com> wrote:
> > On Tue, Jul 6, 2021 at 6:12 PM Arnd Bergmann <arnd@kernel.org> wrote:
> > >  Tue, Jul 6, 2021 at 6:18 AM Huacai Chen <chenhuacai@loongson.cn> wrote:
> > > > --- /dev/null
> > > > +++ b/arch/loongarch/Kbuild
> > > > @@ -0,0 +1,21 @@
> > > > +# Fail on warnings - also for files referenced in subdirs
> > > > +# -Werror can be disabled for specific files using:
> > > > +# CFLAGS_<file.o> := -Wno-error
> > > > +ifeq ($(W),)
> > > > +subdir-ccflags-y := -Werror
> > > > +endif
> > >
> > > This tends to break building with 'make W=12' or similar, I would recommend not
> > > adding -Werror. It is a good idea though to have your CI systems build
> > > with -Werror
> > > enabled on the command line though.
> > If we use W=???, corresponding flags will be used; if we don't use
> > W=???, -Werrer flag is used here. So it seems not break the building.
>
> The thing is that we get three new compiler releases every year, one gcc
> and two llvm. Usually every release introduces new warnings, so even if
> you quickly address those in mainline kernels, anyone using an older kernel
> will find themselves unable to build it with a newer compiler.
OK, I know.

>
> > > > +       select ARCH_MIGHT_HAVE_PC_PARPORT
> > > > +       select ARCH_MIGHT_HAVE_PC_SERIO
> > > > +       select GENERIC_ISA_DMA
> > > > +       select ISA
> > >
> > > Do you actually have ISA-style add-on cards? If not, then
> > > remove the ISA options. If you do, which drivers are they?
> > Yes, there is an LPC controller in LS7A, and superio is connected on
> > it for laptops.
>
> CONFIG_ISA only refers to actual 16-bit add-on cards, not LPC
> style on-board devices. Sometimes the options are used inconsistently,
> but unless you need an original Soundblaster or NE2000 card, this
> should not be needed. Note that some older x86-64 and arm64 have
> LPC as well, but do not support CONFIG_ISA.
>
> For GENERIC_ISA_DMA, I suppose that could be used for the parallel
> port driver, but even if you have one of those, it might be easier to leave
> it out and just no longer support Zip drives or dot matrix printers attached
> to them.
>
> ARCH_MIGHT_HAVE_PC_SERIO is probably needed if this is how
> you attach your keyboard and trackball, but it should work without the
> others.
OK, I'll remove ISA and GENERIC_ISA_DMA.

Huacai
>
>        Arnd