This is a regression introduced by commit ea9f8856bd6d4ed45885b06a338f7362cd6c60e5 https://bugzilla.kernel.org/show_bug.cgi?id=43168 Some platforms don't have _DOS control method, but the ACPI backlight still works. We should not invoke _DOS for these platforms. CC : Igor Murzov <intergalactic.anonymous@xxxxxxxxx> Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx> --- drivers/acpi/video.c | 2 ++ 1 file changed, 2 insertions(+) Index: rtd3/drivers/acpi/video.c =================================================================== --- rtd3.orig/drivers/acpi/video.c +++ rtd3/drivers/acpi/video.c @@ -558,6 +558,8 @@ acpi_video_bus_DOS(struct acpi_video_bus union acpi_object arg0 = { ACPI_TYPE_INTEGER }; struct acpi_object_list args = { 1, &arg0 }; + if (!video->cap._DOS) + return 0; if (bios_flag < 0 || bios_flag > 3 || lcd_flag < 0 || lcd_flag > 1) return -EINVAL; -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
