drm/amdgpu/display: drop DCN support for aarch64
authorAlex Deucher <alexander.deucher@amd.com>
Mon, 4 Jan 2021 16:24:20 +0000 (11:24 -0500)
committerAlex Deucher <alexander.deucher@amd.com>
Tue, 5 Jan 2021 16:35:53 +0000 (11:35 -0500)
commit88d5cb2517a7190d0f51cabbdb2a1e7594bfec21
treeaaf1e43a882ee9b2d6b336eb2eb8b5aae203589f
parent3e7bc83e312e666c648ccda84c745f909fae2256
drm/amdgpu/display: drop DCN support for aarch64

From Ard:

"Simply disabling -mgeneral-regs-only left and right is risky, given that
the standard AArch64 ABI permits the use of FP/SIMD registers anywhere,
and GCC is known to use SIMD registers for spilling, and may invent
other uses of the FP/SIMD register file that have nothing to do with the
floating point code in question. Note that putting kernel_neon_begin()
and kernel_neon_end() around the code that does use FP is not sufficient
here, the problem is in all the other code that may be emitted with
references to SIMD registers in it.

So the only way to do this properly is to put all floating point code in
a separate compilation unit, and only compile that unit with
-mgeneral-regs-only."

Disable support until the code can be properly refactored to support this
properly on aarch64.

Acked-by: Will Deacon <will@kernel.org>
Reported-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
13 files changed:
drivers/gpu/drm/amd/display/Kconfig
drivers/gpu/drm/amd/display/dc/calcs/Makefile
drivers/gpu/drm/amd/display/dc/clk_mgr/Makefile
drivers/gpu/drm/amd/display/dc/dcn10/Makefile
drivers/gpu/drm/amd/display/dc/dcn10/dcn10_resource.c
drivers/gpu/drm/amd/display/dc/dcn20/Makefile
drivers/gpu/drm/amd/display/dc/dcn21/Makefile
drivers/gpu/drm/amd/display/dc/dcn30/Makefile
drivers/gpu/drm/amd/display/dc/dcn301/Makefile
drivers/gpu/drm/amd/display/dc/dcn302/Makefile
drivers/gpu/drm/amd/display/dc/dml/Makefile
drivers/gpu/drm/amd/display/dc/dsc/Makefile
drivers/gpu/drm/amd/display/dc/os_types.h