From 6f6cb1714365a07dbc66851879538df9f6969288 Mon Sep 17 00:00:00 2001
From: Lee Jones <lee@kernel.org>
Date: Fri, 25 Nov 2022 12:07:49 +0000
Subject: [PATCH] drm/amdgpu: temporarily disable broken Clang builds due to
 blown stack-frame
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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>
---
 drivers/gpu/drm/amd/display/Kconfig | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/Kconfig b/drivers/gpu/drm/amd/display/Kconfig
index 6925e0280dbe..f4f3d2665a6b 100644
--- 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