On Sun, Mar 31, 2013 at 08:15:14AM +0200, Danny Baumann wrote: > Artem Savkov <artem.savkov@xxxxxxxxx> schrieb: > >acpi_video_device_lcd_get_level_current() called > >acpi_video_bqc_value_to_level() > >with "*level" as a second argument, resulting in level being returned > >based on > >initial input, not current brightness, breaking backlight controls. > I don't think this change is correct. As level was passed as parameter into the evaluation of _BQC, *level contains the AML returned brightness level afterwards, so it's correct to use it as an input to acpi_video_bqc_value_to_level(). Actually, the whole point of acpi_video_device_lcd_get_level_current() is to update device->brightness->curr, so it doesn't make sense to me to use it in that function. > > What's the exact problem this patch tries to solve? I'm running a -next kernel on my laptop and couple of days ago keyboard backlight controls stopped working: only 2 lower brightness levels. I've debugged it a bit and found out that acpi_video_switch_brightness() calls acpi_video_device_lcd_get_level_current() with level uninitialized and always gets lowest posible value. -- Regards, Artem -- 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
