[PATCH v2 1/1] drm/amd/display: add DCN support for ARM64

[Arnd Bergmann]

On Thu, Oct 27, 2022, at 16:45, 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 at gmail.com>

> 
> +ifdef CONFIG_ARM64
> +ifdef CONFIG_DRM_AMD_DC_DCN
> +dml_rcflags := -mgeneral-regs-only
> +endif
> +endif

I don't think the CONFIG_DRM_AMD_DC_DCN check is needed here,
if the dml_ccflags doesn't have this.

> +ifdef CONFIG_ARM64
> +CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/dcn10/dcn10_fpu.o := $(dml_rcflags)
> +CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/dcn20/dcn20_fpu.o := $(dml_rcflags)
> +CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/dcn314/display_mode_vba_314.o := 
> $(dml_rcflags)

Similarly, this bit should not need a check for CONFIG_ARM64.

> +CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/dcn314/display_rq_dlg_calc_314.o := 
> $(dml_rcflags)
> +CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/dcn314/dcn314_fpu.o := 
> $(dml_rcflags)
> +CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/dcn30/dcn30_fpu.o := $(dml_rcflags)
> +CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/dcn32/dcn32_fpu.o := $(dml_rcflags)
> +CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/dcn321/dcn321_fpu.o := 
> $(dml_rcflags)
> +CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/dcn31/dcn31_fpu.o := $(dml_rcflags)
> +CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/dcn302/dcn302_fpu.o := 
> $(dml_rcflags)
> +CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/dcn303/dcn303_fpu.o := 
> $(dml_rcflags)
> +CFLAGS_REMOVE_$(AMDDALPATH)/dc/dml/calcs/dcn_calc_math.o := 
> $(dml_rcflags)
> +endif
>  endif
>  CFLAGS_$(AMDDALPATH)/dc/dml/dml1_display_rq_dlg_calc.o := 
> $(dml_ccflags)
>  CFLAGS_$(AMDDALPATH)/dc/dml/display_rq_dlg_helpers.o := $(dml_ccflags)

Having the #endif for the CONFIG_DRM_AMD_DC_DCN list is
a bit confusing (this is the preexisting state, not your
change).I'd probably drop the CONFIG_DRM_AMD_DC_DCN check
for the per-file cflags entirely.

      Arnd