nvidia-modeset: skip ACPI native-backlight query when ACPI is disabled - #1273
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jsoltren-bcm wants to merge 1 commit into
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nvidia-modeset: skip ACPI native-backlight query when ACPI is disabled#1273jsoltren-bcm wants to merge 1 commit into
jsoltren-bcm wants to merge 1 commit into
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nvkms_register_backlight() calls acpi_video_backlight_use_native() to decide whether to register NVIDIA's own backlight device or defer to the kernel's native ACPI backlight handling. This call unconditionally consults ACPI video state. On kernels booted with "acpi=off", that state was never initialized, and calling into it during backlight registration causes the nvidia-modeset module to fail to load. Guard the call with a runtime acpi_disabled check (mirroring the existing CONFIG_ACPI pattern used elsewhere in this driver, e.g. nv_platform_supports_s0ix() in nvidia/nv.c) so that when ACPI is disabled at boot, the driver falls through and registers its own backlight device instead of querying ACPI state that doesn't exist.
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nvkms_register_backlight() calls acpi_video_backlight_use_native() to decide whether to register NVIDIA's own backlight device or defer to the kernel's native ACPI backlight handling. This call unconditionally consults ACPI video state.
On kernels booted with "acpi=off", that state was never initialized, and calling into it during backlight registration causes the nvidia-modeset module to fail to load.
Guard the call with a runtime acpi_disabled check (mirroring the existing CONFIG_ACPI pattern used elsewhere in this driver, e.g. nv_platform_supports_s0ix() in nvidia/nv.c) so that when ACPI is disabled at boot, the driver falls through and registers its own backlight device instead of querying ACPI state that doesn't exist.