Am Do., 27. Okt. 2022 um 12:52 Uhr schrieb Arnd Bergmann <arnd@xxxxxxxx>: > > On Thu, Oct 27, 2022, at 02:25, Ao Zhong wrote: > > After moving all FPU code to the DML folder, we can enable DCN support > > for the ARM64 platform. Remove the -mgeneral-regs-only CFLAG from the > > code in the DML folder that needs to use hardware FPU, and add a control > > mechanism for ARM Neon. > > > > Signed-off-by: Ao Zhong <hacc1225@xxxxxxxxx> > > There have been problems with stack frame overflows on this code > in the past, how much have you tested this with random configurations > to see if we still hit them in corner cases on arm64 that may not > show up on x86 or powerpc? I would expect to see a few more of them > for every new architecture port. I just used this patch on my own Desktop and didn't test it much. > > index d0c6cf61c676..3cdd109189e0 100644 > > --- a/drivers/gpu/drm/amd/display/dc/dml/Makefile > > +++ b/drivers/gpu/drm/amd/display/dc/dml/Makefile > > @@ -33,6 +33,12 @@ ifdef CONFIG_PPC64 > > dml_ccflags := -mhard-float -maltivec > > endif > > > > +ifdef CONFIG_ARM64 > > +ifdef CONFIG_DRM_AMD_DC_DCN > > +dml_rcflags_arm64 := -mgeneral-regs-only > > +endif > > +endif > > + > > > CFLAGS_$(AMDDALPATH)/dc/dml/calcs/dcn_calcs.o := $(dml_ccflags) > > CFLAGS_$(AMDDALPATH)/dc/dml/calcs/dcn_calc_auto.o := $(dml_ccflags) > > CFLAGS_$(AMDDALPATH)/dc/dml/calcs/dcn_calc_math.o := $(dml_ccflags) > > -Wno-tautological-compare > > -CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/display_mode_vba.o := $(dml_rcflags) > > +CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/display_mode_vba.o := > > $(dml_rcflags) $(dml_rcflags_arm64) > > Why do you need separate $(dml_rcflags) and $(dml_rcflags_arm64) > rather than adding -mgeneral-regs-only to $(dml_rcflags) directly? > > Arnd I don't know if $(dml_rcflags) has any other use. I'm afraid my patch will break something.
