Re: [PATCH v2 2/2] drm/bridge: add support for lontium lt9211c bridge
From: kernel test robot
Date: Fri Nov 07 2025 - 23:13:13 EST
Hi Nilesh,
kernel test robot noticed the following build errors:
[auto build test ERROR on f50b969bafafb2810a07f376387350c4c0d72a21]
url: https://github.com/intel-lab-lkp/linux/commits/Nilesh-Laad/dt-bindings-bridge-lt9211c-Add-bindings/20251107-210546
base: f50b969bafafb2810a07f376387350c4c0d72a21
patch link: https://lore.kernel.org/r/20251107-add-lt9211c-bridge-v2-2-b0616e23407c%40oss.qualcomm.com
patch subject: [PATCH v2 2/2] drm/bridge: add support for lontium lt9211c bridge
config: loongarch-allmodconfig (https://download.01.org/0day-ci/archive/20251108/202511081122.TMw7Wy9r-lkp@xxxxxxxxx/config)
compiler: clang version 19.1.7 (https://github.com/llvm/llvm-project cd708029e0b2869e80abe31ddb175f7c35361f90)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251108/202511081122.TMw7Wy9r-lkp@xxxxxxxxx/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202511081122.TMw7Wy9r-lkp@xxxxxxxxx/
All error/warnings (new ones prefixed by >>):
>> drivers/gpu/drm/bridge/lontium-lt9211c.c:207:48: warning: '&' within '|' [-Wbitwise-op-parentheses]
207 | ret = regmap_write(ctx->regmap, 0x8180, (pval & 0xfc | 0x03));
| ~~~~~^~~~~~ ~
drivers/gpu/drm/bridge/lontium-lt9211c.c:207:48: note: place parentheses around the '&' expression to silence this warning
207 | ret = regmap_write(ctx->regmap, 0x8180, (pval & 0xfc | 0x03));
| ^
| ( )
drivers/gpu/drm/bridge/lontium-lt9211c.c:227:48: warning: '&' within '|' [-Wbitwise-op-parentheses]
227 | ret = regmap_write(ctx->regmap, 0x8530, (pval & 0xf8 | 0x11));
| ~~~~~^~~~~~ ~
drivers/gpu/drm/bridge/lontium-lt9211c.c:227:48: note: place parentheses around the '&' expression to silence this warning
227 | ret = regmap_write(ctx->regmap, 0x8530, (pval & 0xf8 | 0x11));
| ^
| ( )
drivers/gpu/drm/bridge/lontium-lt9211c.c:253:5: warning: unused variable 'bc' [-Wunused-variable]
253 | u8 bc[3];
| ^~
drivers/gpu/drm/bridge/lontium-lt9211c.c:619:48: warning: '&' within '|' [-Wbitwise-op-parentheses]
619 | ret = regmap_write(ctx->regmap, 0x8530, (pval & 0x3f | 0x40));
| ~~~~~^~~~~~ ~
drivers/gpu/drm/bridge/lontium-lt9211c.c:619:48: note: place parentheses around the '&' expression to silence this warning
619 | ret = regmap_write(ctx->regmap, 0x8530, (pval & 0x3f | 0x40));
| ^
| ( )
>> drivers/gpu/drm/bridge/lontium-lt9211c.c:918:14: error: incompatible function pointer types initializing 'int (*)(struct drm_bridge *, struct drm_encoder *, enum drm_bridge_attach_flags)' with an expression of type 'int (struct drm_bridge *, enum drm_bridge_attach_flags)' [-Wincompatible-function-pointer-types]
918 | .attach = lt9211c_attach,
| ^~~~~~~~~~~~~~
>> drivers/gpu/drm/bridge/lontium-lt9211c.c:920:20: error: incompatible function pointer types initializing 'void (*)(struct drm_bridge *, struct drm_atomic_state *)' with an expression of type 'void (struct drm_bridge *, struct drm_bridge_state *)' [-Wincompatible-function-pointer-types]
920 | .atomic_enable = lt9211c_atomic_enable,
| ^~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/bridge/lontium-lt9211c.c:921:21: error: incompatible function pointer types initializing 'void (*)(struct drm_bridge *, struct drm_atomic_state *)' with an expression of type 'void (struct drm_bridge *, struct drm_bridge_state *)' [-Wincompatible-function-pointer-types]
921 | .atomic_disable = lt9211c_atomic_disable,
| ^~~~~~~~~~~~~~~~~~~~~~
4 warnings and 3 errors generated.
vim +918 drivers/gpu/drm/bridge/lontium-lt9211c.c
916
917 static const struct drm_bridge_funcs lt9211c_funcs = {
> 918 .attach = lt9211c_attach,
919 .mode_valid = lt9211c_mode_valid,
> 920 .atomic_enable = lt9211c_atomic_enable,
921 .atomic_disable = lt9211c_atomic_disable,
922 .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
923 .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
924 .atomic_get_input_bus_fmts = lt9211c_atomic_get_input_bus_fmts,
925 .atomic_reset = drm_atomic_helper_bridge_reset,
926 };
927
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