[PATCH 6.0 094/124] drm/amdgpu: temporarily disable broken Clang builds due to blown stack-frame

Greg Kroah-Hartman
2022-12-05T19:28:14Z

From: Lee Jones <lee@kernel.org>

commit 6f6cb1714365a07dbc66851879538df9f6969288 upstream.

Patch series "Fix a bunch of allmodconfig errors", v2.

Since b339ec9c229aa ("kbuild: Only default to -Werror if COMPILE_TEST")
WERROR now defaults to COMPILE_TEST meaning that it's enabled for
allmodconfig builds. This leads to some interesting build failures when
using Clang, each resolved in this set.

With this set applied, I am able to obtain a successful allmodconfig Arm
build.

This patch (of 2):

calculate_bandwidth() is presently broken on all !(X86_64 || SPARC64 ||
ARM64) architectures built with Clang (all released versions), whereby the
stack frame gets blown up to well over 5k. This would cause an immediate
kernel panic on most architectures. We'll revert this when the following
bug report has been resolved:
https://github.com/llvm/llvm-project/issues/41896.

Link: https://lkml.kernel.org/r/20221125120750.3537134-1-lee@kernel.org
Link: https://lkml.kernel.org/r/20221125120750.3537134-2-lee@kernel.org
Signed-off-by: Lee Jones <lee@kernel.org>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@gmail.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Lee Jones <lee@kernel.org>
Cc: Leo Li <sunpeng.li@amd.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
Cc: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Tom Rix <trix@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/gpu/drm/amd/display/Kconfig | 7 +++++++
1 file changed, 7 insertions(+)

--- a/drivers/gpu/drm/amd/display/Kconfig
+++ b/drivers/gpu/drm/amd/display/Kconfig
@@ -5,6 +5,7 @@ menu "Display Engine Configuration"
config DRM_AMD_DC
bool "AMD DC - Enable new display engine"
default y
+ depends on BROKEN || !CC_IS_CLANG || X86_64 || SPARC64 || ARM64
select SND_HDA_COMPONENT if SND_HDA_CORE
select DRM_AMD_DC_DCN if (X86 || PPC_LONG_DOUBLE_128)
help
@@ -12,6 +13,12 @@ config DRM_AMD_DC
support for AMDGPU. This adds required support for Vega and
Raven ASICs.

+ calculate_bandwidth() is presently broken on all !(X86_64 || SPARC64 || ARM64)
+ architectures built with Clang (all released versions), whereby the stack
+ frame gets blown up to well over 5k. This would cause an immediate kernel
+ panic on most architectures. We'll revert this when the following bug report
+ has been resolved: https://github.com/llvm/llvm-project/issues/41896.
+
config DRM_AMD_DC_DCN
def_bool n
help