On Tue, Jan 26, 2010 at 8:58 AM, Zhang Rui <rui.zhang@xxxxxxxxx> wrote: > On Mon, 2010-01-25 at 17:45 +0800, luke lin wrote: >> Hi all, >> >> I read the drivers/acpi/video.c: >> >> 895 result = acpi_video_device_lcd_set_level(device, max_level); >> 896 if (result) >> 897 goto out_free_levels; >> 898 >> 899 result = acpi_video_device_lcd_get_level_current(device, &level); >> 900 if (result) >> 901 goto out_free_levels; >> 902 >> 903 br->flags._BQC_use_index = (level == max_level ? 0 : 1); >> 904 >> 905 if (!br->flags._BQC_use_index) { >> 912 for (i = 2; i < br->count; i++) >> 913 if (level_old == br->levels[i]) >> 914 level = level_old; >> 915 goto set_level; >> 916 } >> why after level == max_level, it will still need set_level again? >> is this a bug, or it is necessary. >> > Because setting the backlight to max_level is just to check if _BQC uses > indexed value. We need to set the backlight back after this is done. > > thanks, > rui Hi~ I'm wondering why check (level == max_level) can make sure if _BQC uses indexed value? Is it possible that both level and max_level is indexed value? Thank you very much. -- Best Regards, Edward -- 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