Hello, After doing some research myself, I thought it was time to refer to this list for advice. I am using a Lenovo 3000 N100 running Linux 2.6.23-rc4 (x86_64). After loading the video kernel module, I can change the brightness of my display between 0 and 100 by cat $level > /sys/class/backlight/acpi_video0/brightness. However, when using the brightness keys on my keyboard, I can decrease the brightness until 0, but I can never increase it over 42 again. I looked into the code and inserted a printk into the acpi_video_get_next_level() function to print the min, max, level_current, min_above and max_below values when I press the keys, as well as the list of available levels. This is what I got: available levels: 100 57 0 14 28 43 57 71 86 100 Pressing the decrease button: min: 0, max: 100, level_current: 98, min_above: 100, max_below: 86 min: 0, max: 100, level_current: 84, min_above: 86, max_below: 71 min: 0, max: 100, level_current: 70, min_above: 71, max_below: 57 min: 0, max: 100, level_current: 56, min_above: 57, max_below: 43 min: 0, max: 100, level_current: 42, min_above: 43, max_below: 28 min: 0, max: 100, level_current: 28, min_above: 43, max_below: 14 min: 0, max: 100, level_current: 14, min_above: 28, max_below: 0 Pressing the increase button: min: 0, max: 100, level_current: 0, min_above: 14, max_below: 0 min: 0, max: 100, level_current: 14, min_above: 28, max_below: 0 min: 0, max: 100, level_current: 28, min_above: 43, max_below: 14 min: 0, max: 100, level_current: 42, min_above: 43, max_below: 28 min: 0, max: 100, level_current: 42, min_above: 43, max_below: 28 min: 0, max: 100, level_current: 42, min_above: 43, max_below: 28 It seems like Linux thinks that the level 43 is supported (maybe because my bios reported just that), but when it tries to set it to 43, it is actually set to 42. The same seems to be the case for the other levels above 43 as well. As I don't know anything about ACPI, I am stuck here. Any help would be appreciated. - 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
