[PATCH] drm/amdgpu: make DRM_AMD_DC x86-only again

From: Arnd Bergmann <arnd@kernel.org>
To: "Harry Wentland" <harry.wentland@amd.com>,
	"Leo Li" <sunpeng.li@amd.com>,
	"Alex Deucher" <alexander.deucher@amd.com>,
	"Christian König" <christian.koenig@amd.com>,
	"David Airlie" <airlied@linux.ie>,
	"Daniel Vetter" <daniel@ffwll.ch>,
	"Nathan Chancellor" <natechancellor@gmail.com>,
	"Nick Desaulniers" <ndesaulniers@google.com>,
	"Luben Tuikov" <luben.tuikov@amd.com>
Cc: Arnd Bergmann <arnd@arndb.de>,
	Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>,
	Roman Li <Roman.Li@amd.com>, Randy Dunlap <rdunlap@infradead.org>,
	Mauro Rossi <issor.oruam@gmail.com>,
	amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
	linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com
Subject: [PATCH] drm/amdgpu: make DRM_AMD_DC x86-only again
Date: Fri,  4 Dec 2020 09:13:43 +0100	[thread overview]
Message-ID: <20201204081349.1182302-1-arnd@kernel.org> (raw)

From: Arnd Bergmann <arnd@arndb.de>

As the DRM_AMD_DC_DCN3_0 code was x86-only and fails to build on
arm64, merging it into DRM_AMD_DC means that the top-level symbol
is now x86-only as well.

Compilation fails on arm64 with clang-12 with

drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn30/display_mode_vba_30.c:3641:6: error: stack frame size of 2416 bytes in function 'dml30_ModeSupportAndSystemConfigurationFull' [-Werror,-Wframe-larger-than=]
void dml30_ModeSupportAndSystemConfigurationFull(struct display_mode_lib *mode_lib)

I tried to see if the stack usage can be reduced, but this is code
that is described as "This file is gcc-parsable HW gospel, coming
straight from HW engineers." and is written in a way that is inherently
nonportable and not meant to be understood by humans.

There are probably no non-x86 users of this code, so simplify
the dependency list accordingly.

Fixes: 20f2ffe50472 ("drm/amdgpu: fold CONFIG_DRM_AMD_DC_DCN3* into CONFIG_DRM_AMD_DC_DCN (v3)")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/gpu/drm/amd/display/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/Kconfig b/drivers/gpu/drm/amd/display/Kconfig
index 797b5d4b43e5..54aa50d4deba 100644
--- a/drivers/gpu/drm/amd/display/Kconfig
+++ b/drivers/gpu/drm/amd/display/Kconfig
@@ -6,7 +6,7 @@ config DRM_AMD_DC
 	bool "AMD DC - Enable new display engine"
 	default y
 	select SND_HDA_COMPONENT if SND_HDA_CORE
-	select DRM_AMD_DC_DCN if (X86 || PPC64 || (ARM64 && KERNEL_MODE_NEON)) && !(KCOV_INSTRUMENT_ALL && KCOV_ENABLE_COMPARISONS)
+	select DRM_AMD_DC_DCN if X86 && !(KCOV_INSTRUMENT_ALL && KCOV_ENABLE_COMPARISONS)
 	help
 	  Choose this option if you want to use the new display engine
 	  support for AMDGPU. This adds required support for Vega and
-- 
2.27.0

