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From:   Lee Jones <lee@kernel.org>
To:     lee@kernel.org, arnd@arndb.de, akpm@linux-foundation.org,
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Cc:     linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        llvm@lists.linux.dev, amd-gfx@lists.freedesktop.org,
        dri-devel@lists.freedesktop.org
Subject: [PATCH v2 1/2] drm/amdgpu: Temporarily disable broken Clang builds due to blown stack-frame
Date:   Fri, 25 Nov 2022 12:07:49 +0000
Message-Id: <20221125120750.3537134-2-lee@kernel.org>
In-Reply-To: <20221125120750.3537134-1-lee@kernel.org>
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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.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Lee Jones <lee@kernel.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 6925e0280dbe6..f4f3d2665a6b2 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
-- 
2.38.1.584.g0f3c55d4c2-goog