[RFC PATCH] DRM: amd: powerplay: don't undef pr_warn() {causes ARC build errors}

[Randy Dunlap]

From: Randy Dunlap <rdunlap at infradead.org>

arch/arc/ implements BUG_ON() with BUG(). ARC has its own BUG()
function and that function uses pr_warn() as part of its implementation.

Several (8) files in amd/powerplay/ #undef various pr_xyz() functions so
that they won't be used by these drivers, since dev_() functions are
preferred here and the #undefs make the pr_() functions unavailable.

Hence the following build errors are reported in ARC builds:

../drivers/gpu/drm/amd/amdgpu/../powerplay/navi10_ppt.c: In function 'navi10_fill_i2c_req':
../arch/arc/include/asm/bug.h:24:2: error: implicit declaration of function 'pr_warn'; did you mean 'drm_warn'? [-Werror=implicit-function-declaration]

../drivers/gpu/drm/amd/amdgpu/../powerplay/sienna_cichlid_ppt.c: In function 'sienna_cichlid_fill_i2c_req':
../arch/arc/include/asm/bug.h:24:2: error: implicit declaration of function 'pr_warn'; did you mean 'drm_warn'? [-Werror=implicit-function-declaration]

Fixes: 55084d7f4022 ("drm/amd/powerplay: forbid to use pr_err/warn/info/debug")
Reported-by: kernel test robot <lkp at intel.com>
Signed-off-by: Randy Dunlap <rdunlap at infradead.org>
Cc: Evan Quan <evan.quan at amd.com>
Cc: amd-gfx at lists.freedesktop.org
Cc: Alex Deucher <alexander.deucher at amd.com>
Cc: Vineet Gupta <vgupta at synopsys.com>
Cc: linux-snps-arc at lists.infradead.org
---
Another alternative is for amd/powerplay/ drivers not to use BUG()
or BUG_ON().
A third alternative is to ask the ARC developers to implement BUG()
without using any pr_() functions.

 drivers/gpu/drm/amd/powerplay/navi10_ppt.c         |    2 +-
 drivers/gpu/drm/amd/powerplay/sienna_cichlid_ppt.c |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

--- lnx-59-rc7.orig/drivers/gpu/drm/amd/powerplay/navi10_ppt.c
+++ lnx-59-rc7/drivers/gpu/drm/amd/powerplay/navi10_ppt.c
@@ -52,7 +52,7 @@
  * They are more MGPU friendly.
  */
 #undef pr_err
-#undef pr_warn
+//#undef pr_warn
 #undef pr_info
 #undef pr_debug
 
--- lnx-59-rc7.orig/drivers/gpu/drm/amd/powerplay/sienna_cichlid_ppt.c
+++ lnx-59-rc7/drivers/gpu/drm/amd/powerplay/sienna_cichlid_ppt.c
@@ -54,7 +54,7 @@
  * They are more MGPU friendly.
  */
 #undef pr_err
-#undef pr_warn
+//#undef pr_warn
 #undef pr_info
 #undef pr_debug