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@amd.com wrote:
On 2019-01-24 7:52 p.m., ndesaulniers@google.com 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@vger.kernel.org # 4.19 Reported-by: S, Shirish Shirish.S@amd.com Reported-by: Matthias Kaehlcke mka@google.com Suggested-by: James Y Knight jyknight@google.com Suggested-by: Nathan Chancellor natechancellor@gmail.com Signed-off-by: Nick Desaulniers ndesaulniers@google.com Tested-by: Guenter Roeck linux@roeck-us.net
Reviewed-by: Harry Wentland harry.wentland@amd.com
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.
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)
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