On Mon, Aug 25, 2025 at 4:54 PM Xi Ruoyao <xry...@xry111.site> wrote: > > dml21_map_dc_state_into_dml_display_cfg calls (the call is usually > inlined by the compiler) populate_dml21_surface_config_from_plane_state > and populate_dml21_plane_config_from_plane_state which may use FPU. In > a x86-64 build: > > $ objdump --disassemble=dml21_map_dc_state_into_dml_display_cfg \ > > drivers/gpu/drm/amd/display/dc/dml2/dml21/dml21_translation_helper.o | > > grep %xmm -c > 63 > > Thus it needs to be guarded with DC_FP_START. But we must note that the > current code quality of the in-kernel FPU use in AMD dml2 is very much > problematic: we are actually calling DC_FP_START in dml21_wrapper.c > here, and this translation unit is built with CC_FLAGS_FPU. Strictly > speaking this does not make any sense: with CC_FLAGS_FPU the compiler is > allowed to generate FPU uses anywhere in the translated code, perhaps > out of the DC_FP_START guard. This problematic pattern also occurs in > at least dml2_wrapper.c, dcn35_fpu.c, and dcn351_fpu.c. Thus we really > need a careful audit and refactor for the in-kernel FPU uses, and this > patch is simply whacking a mole. However per the reporter, whacking > this mole is enough to make a 9060XT "just work." > > Reported-by: Asiacn <710187...@qq.com> > Link: https://github.com/loongson-community/discussions/issues/102 > Tested-by: Asiacn <710187...@qq.com> > Signed-off-by: Xi Ruoyao <xry...@xry111.site> Reviewed-by: Huacai Chen <chenhua...@loongson.cn>
> --- > drivers/gpu/drm/amd/display/dc/dml2/dml21/dml21_wrapper.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/gpu/drm/amd/display/dc/dml2/dml21/dml21_wrapper.c > b/drivers/gpu/drm/amd/display/dc/dml2/dml21/dml21_wrapper.c > index 03de3cf06ae5..059ede6ff256 100644 > --- a/drivers/gpu/drm/amd/display/dc/dml2/dml21/dml21_wrapper.c > +++ b/drivers/gpu/drm/amd/display/dc/dml2/dml21/dml21_wrapper.c > @@ -224,7 +224,9 @@ static bool dml21_mode_check_and_programming(const struct > dc *in_dc, struct dc_s > > dml_ctx->config.svp_pstate.callbacks.release_phantom_streams_and_planes(in_dc, > context); > > /* Populate stream, plane mappings and other fields in display > config. */ > + DC_FP_START(); > result = dml21_map_dc_state_into_dml_display_cfg(in_dc, context, > dml_ctx); > + DC_FP_END(); > if (!result) > return false; > > @@ -279,7 +281,9 @@ static bool dml21_check_mode_support(const struct dc > *in_dc, struct dc_state *co > > dml_ctx->config.svp_pstate.callbacks.release_phantom_streams_and_planes(in_dc, > context); > > mode_support->dml2_instance = dml_init->dml2_instance; > + DC_FP_START(); > dml21_map_dc_state_into_dml_display_cfg(in_dc, context, dml_ctx); > + DC_FP_END(); > > dml_ctx->v21.mode_programming.dml2_instance->scratch.build_mode_programming_locals.mode_programming_params.programming > = dml_ctx->v21.mode_programming.programming; > DC_FP_START(); > is_supported = dml2_check_mode_supported(mode_support); > -- > 2.51.0 > >
