[PATCH] drm/amd/display: Limit DCN to x86 arch

[Christian König]

Am 19.05.2017 um 16:01 schrieb Harry Wentland:
> DCN bw calcs currently rely on the following gcc options:
>    -mhard-float -msse -mpreferred-stack-boundary=4

Mhm, price question: Why does DCN rely on the gcc options?

That is something very unusual for drivers. We occasionally have 
something like enabling additional warnings, but things like 
"-mhard-float" is clearly raising an eyebrow here.

Christian.

>
> We probably shouldn't allow building this on architectures
> other than x86.
>
> CC: Alex Deucher <Alexander.Deucher at amd.com>
> CC: Christian König <christian.koenig at amd.com>
> CC: Michel Dänzer <michel.daenzer at amd.com>
> CC: Tony Cheng <Tony.Cheng at amd.com>
> CC: Dmytro Laktyushkin <Dmytro.Laktyushkin at amd.com>
> Signed-off-by: Harry Wentland <harry.wentland at amd.com>
> ---
>
> Tested this change by running make menuconfig and make modules with
> ARCH=arm.
>
> Harry
>
>   drivers/gpu/drm/amd/display/Kconfig           | 2 +-
>   drivers/gpu/drm/amd/display/dc/calcs/Makefile | 2 ++
>   2 files changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/display/Kconfig b/drivers/gpu/drm/amd/display/Kconfig
> index 2b8d77cebe03..62ea9f600374 100644
> --- a/drivers/gpu/drm/amd/display/Kconfig
> +++ b/drivers/gpu/drm/amd/display/Kconfig
> @@ -11,7 +11,7 @@ config DRM_AMD_DC
>   
>   config DRM_AMD_DC_DCN1_0
>           bool "DCN 1.0 Raven family"
> -        depends on DRM_AMD_DC
> +        depends on DRM_AMD_DC && X86
>           help
>               Choose this option if you want to have
>               RV family for display engine
> diff --git a/drivers/gpu/drm/amd/display/dc/calcs/Makefile b/drivers/gpu/drm/amd/display/dc/calcs/Makefile
> index a095472bf4b5..2e4ce0918c02 100644
> --- a/drivers/gpu/drm/amd/display/dc/calcs/Makefile
> +++ b/drivers/gpu/drm/amd/display/dc/calcs/Makefile
> @@ -3,9 +3,11 @@
>   # It calculates Bandwidth and Watermarks values for HW programming
>   #
>   
> +ifeq ($(ARCH),x86)
>   CFLAGS_dcn_calcs.o := -mhard-float -msse -mpreferred-stack-boundary=4
>   CFLAGS_dcn_calc_auto.o := -mhard-float -msse -mpreferred-stack-boundary=4
>   CFLAGS_dcn_calc_math.o := -mhard-float -msse -mpreferred-stack-boundary=4
> +endif
>   
>   BW_CALCS = dce_calcs.o bw_fixed.o custom_float.o
>