Suggestions: 1. revert patch 2. get me the disassembly from gcc of the translation unit in question. 3. land patch that adds clang guards or something different based on 2. Revert first; ask questions later. On Tue, Jan 29, 2019 at 11:01 AM Wentland, Harry <Harry.Wentland@xxxxxxx> wrote: > > On 2019-01-29 1:56 p.m., Guenter Roeck wrote: > > On Tue, Jan 29, 2019 at 10:30:31AM -0500, Alex Deucher wrote: > >> On Fri, Jan 25, 2019 at 10:29 AM Wentland, Harry <Harry.Wentland@xxxxxxx> wrote: > >>> > >>> On 2019-01-24 7:52 p.m., ndesaulniers@xxxxxxxxxx wrote: > >>>> arch/x86/Makefile disables SSE and SSE2 for the whole kernel. The > >>>> AMDGPU drivers modified in this patch re-enable SSE but not SSE2. Turn > >>>> on SSE2 to support emitting double precision floating point instructions > >>>> rather than calls to non-existent (usually available from gcc_s or > >>>> compiler_rt) floating point helper routines. > >>>> > >>>> Link: https://gcc.gnu.org/onlinedocs/gccint/Soft-float-library-routines.html > >>>> Link: https://github.com/ClangBuiltLinux/linux/issues/327 > >>>> Cc: stable@xxxxxxxxxxxxxxx # 4.19 > >>>> Reported-by: S, Shirish <Shirish.S@xxxxxxx> > >>>> Reported-by: Matthias Kaehlcke <mka@xxxxxxxxxx> > >>>> Suggested-by: James Y Knight <jyknight@xxxxxxxxxx> > >>>> Suggested-by: Nathan Chancellor <natechancellor@xxxxxxxxx> > >>>> Signed-off-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> > >>>> Tested-by: Guenter Roeck <linux@xxxxxxxxxxxx> > >>> > >>> Reviewed-by: Harry Wentland <harry.wentland@xxxxxxx> > >>> > >>> and applied. > >>> > >> > >> This patch causes a segfault: > >> https://bugs.freedesktop.org/show_bug.cgi?id=109487 > >> > >> Any ideas? > >> > > > > Set -msse2 only for clang ? I suspect, though, that this might only > > solve the compile problem. If I understand correctly, the first > > warning in the log is due to BREAK_TO_DEBUGGER(), suggesting that > > something is seriously wrong. Maybe enabling sse2 results in different > > results from floating point operations. > > > > Unfortunately I don't have a system with the affected GPU, > > so I can't run any tests on real hardware. Unless someone can test > > with real hardware, I think we have no choice but to revert the > > patch. > > > > Might be a good idea. Even though, best to revert for now until we understand what's going on. > > It seems like people at AMD building with gcc 5.4 are fine, but those using gcc 7.3 or 8.2 experience the crash. > > Harry > > > Guenter > > > >> Alex > >> > >>> Harry > >>> > >>>> --- > >>>> drivers/gpu/drm/amd/display/dc/calcs/Makefile | 2 +- > >>>> drivers/gpu/drm/amd/display/dc/dml/Makefile | 2 +- > >>>> 2 files changed, 2 insertions(+), 2 deletions(-) > >>>> > >>>> diff --git a/drivers/gpu/drm/amd/display/dc/calcs/Makefile b/drivers/gpu/drm/amd/display/dc/calcs/Makefile > >>>> index 95f332ee3e7e..dc85a3c088af 100644 > >>>> --- a/drivers/gpu/drm/amd/display/dc/calcs/Makefile > >>>> +++ b/drivers/gpu/drm/amd/display/dc/calcs/Makefile > >>>> @@ -30,7 +30,7 @@ else ifneq ($(call cc-option, -mstack-alignment=16),) > >>>> cc_stack_align := -mstack-alignment=16 > >>>> endif > >>>> > >>>> -calcs_ccflags := -mhard-float -msse $(cc_stack_align) > >>>> +calcs_ccflags := -mhard-float -msse -msse2 $(cc_stack_align) > >>>> > >>>> CFLAGS_dcn_calcs.o := $(calcs_ccflags) > >>>> CFLAGS_dcn_calc_auto.o := $(calcs_ccflags) > >>>> diff --git a/drivers/gpu/drm/amd/display/dc/dml/Makefile b/drivers/gpu/drm/amd/display/dc/dml/Makefile > >>>> index d97ca6528f9d..33c7d7588712 100644 > >>>> --- a/drivers/gpu/drm/amd/display/dc/dml/Makefile > >>>> +++ b/drivers/gpu/drm/amd/display/dc/dml/Makefile > >>>> @@ -30,7 +30,7 @@ else ifneq ($(call cc-option, -mstack-alignment=16),) > >>>> cc_stack_align := -mstack-alignment=16 > >>>> endif > >>>> > >>>> -dml_ccflags := -mhard-float -msse $(cc_stack_align) > >>>> +dml_ccflags := -mhard-float -msse -msse2 $(cc_stack_align) > >>>> > >>>> CFLAGS_display_mode_lib.o := $(dml_ccflags) > >>>> CFLAGS_display_pipe_clocks.o := $(dml_ccflags) > >>>> > >>> _______________________________________________ > >>> amd-gfx mailing list > >>> amd-gfx@xxxxxxxxxxxxxxxxxxxxx > >>> https://lists.freedesktop.org/mailman/listinfo/amd-gfx -- Thanks, ~Nick Desaulniers _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
