drm/amdgpu: temporarily disable broken Clang builds due to blown stack-frame

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>

diff --git a/drivers/gpu/drm/amd/display/Kconfig b/drivers/gpu/drm/amd/display/Kconfig
index 6925e02..f4f3d26 100644 (file)
--- 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