From d11219ad53dcf61ced53ca60fe0c4a8d34393e6c Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Wed, 13 Jul 2022 12:36:50 -0700
Subject: [PATCH] amdgpu: disable powerpc support for the newer display engine
References: bsc#1194869
Patch-mainline: v5.19-rc7
Git-commit: d11219ad53dcf61ced53ca60fe0c4a8d34393e6c
The DRM_AMD_DC_DCN display engine support (Raven, Navi, and newer) has
not been building cleanly on powerpc and causes link errors due to
mixing hard- and soft-float object files:
powerpc64-linux-ld: drivers/gpu/drm/amd/amdgpu/../display/dc/dml/display_mode_lib.o uses hard float, drivers/gpu/drm/amd/amdgpu/../display/dc/dcn31/dcn31_resource.o uses soft float
powerpc64-linux-ld: failed to merge target specific data of file drivers/gpu/drm/amd/amdgpu/../display/dc/dcn31/dcn31_resource.o
[..]
and while patches are floating around, it's not exactly obvious what is
going on.
The problem bisects to commit 41b7a347bf14 ("powerpc: Book3S 64-bit
outline-only KASAN support") but that is probably more about changing
config variables than the fundamental cause.
Despite the bisection result, a more directly related commit seems to be
26f4712aedbd ("drm/amd/display: move FPU related code from dcn31 to
dml/dcn31 folder"). It's probably a combination of the two.
This has been going on since the merge window, without any final word.
So instead of blindly applying patches that may or may not be the right
thing, let's disable this for now.
As Michael Ellerman says:
"IIUIC this code was never enabled on ppc before, so disabling it seems
like a reasonable fix to get the build clean"
and once we have more actual feedback (and find any potential users) we
can always re-enable it with the patch that fixes the issues and
back-port as necessary.
Fixes: 41b7a347bf14 ("powerpc: Book3S 64-bit outline-only KASAN support")
Fixes: 26f4712aedbd ("drm/amd/display: move FPU related code from dcn31 to dml/dcn31 folder")
Reported-and-tested-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/all/20220606153910.GA1773067@roeck-us.net/
Link: https://lore.kernel.org/all/20220618232737.2036722-1-linux@roeck-us.net/
Link: https://lore.kernel.org/all/20220713050724.GA2471738@roeck-us.net/
Acked-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
drivers/gpu/drm/amd/display/Kconfig | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/display/Kconfig b/drivers/gpu/drm/amd/display/Kconfig
index b4029c0d5d8c..0ba0598eba20 100644
--- a/drivers/gpu/drm/amd/display/Kconfig
+++ b/drivers/gpu/drm/amd/display/Kconfig
@@ -6,7 +6,7 @@ config DRM_AMD_DC
bool "AMD DC - Enable new display engine"
default y
select SND_HDA_COMPONENT if SND_HDA_CORE
- select DRM_AMD_DC_DCN if (X86 || PPC64) && !(KCOV_INSTRUMENT_ALL && KCOV_ENABLE_COMPARISONS)
+ select DRM_AMD_DC_DCN if X86 && !(KCOV_INSTRUMENT_ALL && KCOV_ENABLE_COMPARISONS)
help
Choose this option if you want to use the new display engine
support for AMDGPU. This adds required support for Vega and
--
2.40.0