Hi all, After merging the header_cleanup tree, today's linux-next build (arm multi_v7_defconfig) failed like this: In file included from include/linux/kernel.h:27, from drivers/gpu/ipu-v3/ipu-dp.c:7: include/drm/drm_color_mgmt.h: In function 'drm_color_lut_extract': include/drm/drm_color_mgmt.h:45:46: error: implicit declaration of function 'mul_u32_u32' [-Werror=implicit-function-declaration] 45 | return DIV_ROUND_CLOSEST_ULL(mul_u32_u32(user_input, (1 << bit_precision) - 1), | ^~~~~~~~~~~ include/linux/math.h:104:36: note: in definition of macro 'DIV_ROUND_CLOSEST_ULL' 104 | unsigned long long _tmp = (x) + (__d) / 2; \ | ^ In file included from include/linux/time.h:6, from include/linux/videodev2.h:59, from include/video/imx-ipu-v3.h:16, from drivers/gpu/ipu-v3/ipu-dp.c:14: include/linux/math64.h: At top level: include/linux/math64.h:155:19: error: conflicting types for 'mul_u32_u32'; have 'u64(u32, u32)' {aka 'long long unsigned int(unsigned int, unsigned int)'} 155 | static inline u64 mul_u32_u32(u32 a, u32 b) | ^~~~~~~~~~~ include/drm/drm_color_mgmt.h:45:46: note: previous implicit declaration of 'mul_u32_u32' with type 'int()' 45 | return DIV_ROUND_CLOSEST_ULL(mul_u32_u32(user_input, (1 << bit_precision) - 1), | ^~~~~~~~~~~ include/linux/math.h:104:36: note: in definition of macro 'DIV_ROUND_CLOSEST_ULL' 104 | unsigned long long _tmp = (x) + (__d) / 2; \ | ^ cc1: some warnings being treated as errors In file included from include/linux/kernel.h:27, from drivers/gpu/drm/omapdrm/dss/dispc_coefs.c:7: include/drm/drm_color_mgmt.h: In function 'drm_color_lut_extract': include/drm/drm_color_mgmt.h:45:46: error: implicit declaration of function 'mul_u32_u32' [-Werror=implicit-function-declaration] 45 | return DIV_ROUND_CLOSEST_ULL(mul_u32_u32(user_input, (1 << bit_precision) - 1), | ^~~~~~~~~~~ include/linux/math.h:104:36: note: in definition of macro 'DIV_ROUND_CLOSEST_ULL' 104 | unsigned long long _tmp = (x) + (__d) / 2; \ | ^ In file included from include/linux/jiffies.h:7, from include/linux/ktime.h:25, from include/linux/timer.h:6, from include/linux/workqueue.h:9, from include/linux/mm_types.h:19, from include/linux/mmzone.h:22, from include/linux/gfp.h:7, from include/linux/stackdepot.h:25, from include/drm/drm_modeset_lock.h:28, from include/drm/drm_crtc.h:30, from drivers/gpu/drm/omapdrm/dss/omapdss.h:11, from drivers/gpu/drm/omapdrm/dss/dispc_coefs.c:9: include/linux/math64.h: At top level: include/linux/math64.h:155:19: error: conflicting types for 'mul_u32_u32'; have 'u64(u32, u32)' {aka 'long long unsigned int(unsigned int, unsigned int)'} 155 | static inline u64 mul_u32_u32(u32 a, u32 b) | ^~~~~~~~~~~ include/drm/drm_color_mgmt.h:45:46: note: previous implicit declaration of 'mul_u32_u32' with type 'int()' 45 | return DIV_ROUND_CLOSEST_ULL(mul_u32_u32(user_input, (1 << bit_precision) - 1), | ^~~~~~~~~~~ include/linux/math.h:104:36: note: in definition of macro 'DIV_ROUND_CLOSEST_ULL' 104 | unsigned long long _tmp = (x) + (__d) / 2; \ | ^ cc1: some warnings being treated as errors I have dropped the header_cleanup tree for today. -- Cheers, Stephen Rothwell