Re: [PATCH 4/6] drm/amd/display: fix dcn21 Makefile for clang

[Alex Deucher]

On Wed, Oct 2, 2019 at 11:39 AM Arnd Bergmann <arnd@xxxxxxxx> wrote:
>
> On Wed, Oct 2, 2019 at 5:12 PM Alex Deucher <alexdeucher@xxxxxxxxx> wrote:
> > On Wed, Oct 2, 2019 at 10:51 AM Arnd Bergmann <arnd@xxxxxxxx> wrote:
>
> > >
> > > Nothing should really change with regards to the -msse flag here, only
> > > the stack alignment flag changed. Maybe there was some other change
> > > in your Makefile that conflicts with my my patch?
> >
> > This patch on top of yours seems to fix it and aligns better with the
> > other Makefiles:
> >
> > diff --git a/drivers/gpu/drm/amd/display/dc/dcn21/Makefile
> > b/drivers/gpu/drm/amd/display/dc/dcn21/Makefile
> > index ef673bffc241..e71f3ee76cd1 100644
> > --- a/drivers/gpu/drm/amd/display/dc/dcn21/Makefile
> > +++ b/drivers/gpu/drm/amd/display/dc/dcn21/Makefile
> > @@ -9,10 +9,10 @@ else ifneq ($(call cc-option, -mstack-alignment=16),)
> >         cc_stack_align := -mstack-alignment=16
> >  endif
> >
> > -CFLAGS_$(AMDDALPATH)/dc/dcn21/dcn21_resource.o := -mhard-float -msse
> > $(cc_stack_align)
> > +CFLAGS_dcn21_resource.o := -mhard-float -msse $(cc_stack_align)
> >
> >  ifdef CONFIG_CC_IS_CLANG
> > -CFLAGS_$(AMDDALPATH)/dc/dcn21/dcn21_resource.o += -msse2
> > +CFLAGS_dcn21_resource.o += -msse2
> >  endif
>
> Ok, so there is clearly a global change that went into your tree, or
> is missing from it:
>
> I see that as of linux-5.4-rc1, I have commit 54b8ae66ae1a ("kbuild: change
>  *FLAGS_<basetarget>.o to take the path relative to $(obj)"), which changed
> all these path names to include the AMDDALPATH.
>
> It seems you are either on an older kernel that does not yet have this,
> or you have applied another patch that reverts it.

Ah, I don't have that patch yet in my tree.  That explains it.

Alex