next-20251027: backlight.c:59:39: error: implicit declaration of function 'of_find_node_by_name'; did you mean 'bus_find_device_by_name'?
Naresh Kamboju
naresh.kamboju at linaro.org
Mon Oct 27 19:38:05 AEDT 2025
On Mon, 27 Oct 2025 at 13:43, Naresh Kamboju <naresh.kamboju at linaro.org> wrote:
>
> The following powerpc ppc6xx_defconfig build regressions noticed on the
> Linux next-20251027 tag with gcc-14 and gcc-8.
>
> * powerpc, build
> - gcc-14-ppc6xx_defconfig
> - gcc-8-ppc6xx_defconfig
>
> First seen on next-20251027
> Good: next-20251024
> Bad: next-20251027
>
> Regression Analysis:
> - New regression? yes
> - Reproducibility? yes
>
> Build regression: next-20251027: backlight.c:59:39: error: implicit
> declaration of function 'of_find_node_by_name'; did you mean
> 'bus_find_device_by_name'?
> Build regression: next-20251027: include/linux/math.h:167:43: error:
> first argument to '__builtin_choose_expr' not a constant
> Build regression: next-20251027: via-pmu-backlight.c:22:20: error:
> 'FB_BACKLIGHT_LEVELS' undeclared here (not in a function)
> Build regression: next-20251027: minmax.h:71:17: error: first argument
> to '__builtin_choose_expr' not a constant
> Build regression: next-20251027: compiler.h:168:17: error:
> '__UNIQUE_ID_x__286' undeclared (first use in this function); did you
> mean '__UNIQUE_ID_y__287'?
Anders bisected this down to,
# first bad commit:
[243ce64b2b371cdf2cbc39c9422cb3047cab6de7]
backlight: Do not include <linux/fb.h> in header file
>
> Reported-by: Linux Kernel Functional Testing <lkft at linaro.org>
>
> ## Build error
> arch/powerpc/platforms/powermac/backlight.c: In function
> 'pmac_has_backlight_type':
> arch/powerpc/platforms/powermac/backlight.c:59:39: error: implicit
> declaration of function 'of_find_node_by_name'; did you mean
> 'bus_find_device_by_name'? [-Wimplicit-function-declaration]
> 59 | struct device_node* bk_node =
> of_find_node_by_name(NULL, "backlight");
> | ^~~~~~~~~~~~~~~~~~~~
> | bus_find_device_by_name
> arch/powerpc/platforms/powermac/backlight.c:59:39: error:
> initialization of 'struct device_node *' from 'int' makes pointer from
> integer without a cast [-Wint-conversion]
> arch/powerpc/platforms/powermac/backlight.c:60:17: error: implicit
> declaration of function 'of_property_match_string'
> [-Wimplicit-function-declaration]
> 60 | int i = of_property_match_string(bk_node,
> "backlight-control", type);
> | ^~~~~~~~~~~~~~~~~~~~~~~~
> arch/powerpc/platforms/powermac/backlight.c:62:9: error: implicit
> declaration of function 'of_node_put'
> [-Wimplicit-function-declaration]
> 62 | of_node_put(bk_node);
> | ^~~~~~~~~~~
> drivers/macintosh/via-pmu-backlight.c:22:20: error:
> 'FB_BACKLIGHT_LEVELS' undeclared here (not in a function)
> 22 | static u8 bl_curve[FB_BACKLIGHT_LEVELS];
> | ^~~~~~~~~~~~~~~~~~~
> In file included from <command-line>:
> drivers/macintosh/via-pmu-backlight.c: In function 'pmu_backlight_curve_lookup':
> include/linux/compiler.h:168:17: error: '__UNIQUE_ID_x__286'
> undeclared (first use in this function); did you mean
> '__UNIQUE_ID_y__287'?
> 168 | __PASTE(__UNIQUE_ID_, \
> | ^~~~~~~~~~~~
> drivers/macintosh/via-pmu-backlight.c:45:23: note: in expansion of macro 'max'
> 45 | max = max((int)bl_curve[i], max);
> | ^~~
> include/linux/minmax.h:71:17: error: first argument to
> '__builtin_choose_expr' not a constant
> 71 | (typeof(__builtin_choose_expr(sizeof(ux) > 4, 1LL,
> 1L)))(ux) >= 0)
> | ^~~~~~~~~~~~~~~~~~~~~
> include/linux/compiler_types.h:577:23: note: in definition of macro
> '__compiletime_assert'
> 577 | if (!(condition))
> \
> | ^~~~~~~~~
> drivers/macintosh/via-pmu-backlight.c:45:23: note: in expansion of macro 'max'
> 45 | max = max((int)bl_curve[i], max);
> | ^~~
> include/linux/minmax.h:71:17: error: first argument to
> '__builtin_choose_expr' not a constant
> 71 | (typeof(__builtin_choose_expr(sizeof(ux) > 4, 1LL,
> 1L)))(ux) >= 0)
> | ^~~~~~~~~~~~~~~~~~~~~
> include/linux/compiler_types.h:577:23: note: in definition of macro
> '__compiletime_assert'
> 577 | if (!(condition))
> \
> | ^~~~~~~~~
> include/linux/minmax.h:112:25: note: in expansion of macro '__careful_cmp'
> 112 | #define max(x, y) __careful_cmp(max, x, y)
> | ^~~~~~~~~~~~~
> drivers/macintosh/via-pmu-backlight.c:45:23: note: in expansion of macro 'max'
> 45 | max = max((int)bl_curve[i], max);
> | ^~~
> In file included from include/linux/kernel.h:27,
> from arch/powerpc/include/asm/page.h:11,
> from arch/powerpc/include/asm/thread_info.h:13,
> from include/linux/thread_info.h:60,
> from arch/powerpc/include/asm/ptrace.h:342,
> from drivers/macintosh/via-pmu-backlight.c:11:
> include/linux/math.h:162:17: error: first argument to
> '__builtin_choose_expr' not a constant
> 162 | __builtin_choose_expr(
> \
> | ^~~~~~~~~~~~~~~~~~~~~
>
> drivers/macintosh/via-pmu-backlight.c: In function
> 'pmu_backlight_get_level_brightness':
> drivers/macintosh/via-pmu-backlight.c:63:38: error: 'FB_BACKLIGHT_MAX'
> undeclared (first use in this function); did you mean 'BACKLIGHT_RAW'?
> 63 | pmulevel = bl_curve[level] * FB_BACKLIGHT_MAX / MAX_PMU_LEVEL;
> | ^~~~~~~~~~~~~~~~
> | BACKLIGHT_RAW
> drivers/macintosh/via-pmu-backlight.c:58:51: warning: parameter
> 'level' set but not used [-Wunused-but-set-parameter]
> 58 | static int pmu_backlight_get_level_brightness(int level)
> | ~~~~^~~~~
> drivers/macintosh/via-pmu-backlight.c: In function 'pmu_backlight_init':
> drivers/macintosh/via-pmu-backlight.c:144:17: error: implicit
> declaration of function 'of_machine_is_compatible'
> [-Wimplicit-function-declaration]
> 144 | of_machine_is_compatible("AAPL,3400/2400") ||
> | ^~~~~~~~~~~~~~~~~~~~~~~~
> drivers/macintosh/via-pmu-backlight.c: At top level:
> drivers/macintosh/via-pmu-backlight.c:22:11: warning: 'bl_curve'
> defined but not used [-Wunused-variable]
> 22 | static u8 bl_curve[FB_BACKLIGHT_LEVELS];
> | ^~~~~~~~
> make[5]: *** [scripts/Makefile.build:287:
> drivers/macintosh/via-pmu-backlight.o] Error 1
> make[5]: Target 'drivers/macintosh/' not remade because of errors.
>
>
> ## Source
> * Kernel version: 6.18.0-rc2-next-20251027
> * Git tree: https://kernel.googlesource.com/pub/scm/linux/kernel/git/next/linux-next.git
> * Git describe: next-20251027
> * Git commit: 8fec172c82c2b5f6f8e47ab837c1dc91ee3d1b87
> * Architectures: powerpc
> * Toolchains: gcc-14
> * Kconfigs: defconfig
>
> ## Build
> * Test log: https://storage.tuxsuite.com/public/linaro/lkft/builds/34dKrlb77LGOQQSoC8FHCiIEAZK/build.log
> * Test details:
> https://regressions.linaro.org/lkft/linux-next-master/next-20251027/build/gcc-14-ppc6xx_defconfig/
> * Build plan: https://tuxapi.tuxsuite.com/v1/groups/linaro/projects/lkft/builds/34dKrlb77LGOQQSoC8FHCiIEAZK
> * Build link: https://storage.tuxsuite.com/public/linaro/lkft/builds/34dKrlb77LGOQQSoC8FHCiIEAZK/
> * Kernel config:
> https://storage.tuxsuite.com/public/linaro/lkft/builds/34dKrlb77LGOQQSoC8FHCiIEAZK/config
>
> --
> Linaro LKFT
- Naresh
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