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

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

Since b339ec9 ("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:
llvm/llvm-project#41896.

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Lee Jones <[email protected]>
Suggested-by: Arnd Bergmann <[email protected]>
Acked-by: Arnd Bergmann <[email protected]>
Cc: Alex Deucher <[email protected]>
Cc: "Christian König" <[email protected]>
Cc: Daniel Vetter <[email protected]>
Cc: David Airlie <[email protected]>
Cc: Harry Wentland <[email protected]>
Cc: Lee Jones <[email protected]>
Cc: Leo Li <[email protected]>
Cc: Maarten Lankhorst <[email protected]>
Cc: Maxime Ripard <[email protected]>
Cc: Nathan Chancellor <[email protected]>
Cc: Nick Desaulniers <[email protected]>
Cc: "Pan, Xinhui" <[email protected]>
Cc: Rodrigo Siqueira <[email protected]>
Cc: Thomas Zimmermann <[email protected]>
Cc: Tom Rix <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

Author: lag-linaro

drivers/gpu/drm/amd/display/Kconfig

@@ -5,13 +5,20 @@ 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
 	  Choose this option if you want to use the new display engine
 	  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