Distribution: Ubuntu Hardy 8.04 Hardware Environment: Sony Vaio TX2 Software Environment: i386 Problem Description: Sony TX series and possible other Sony laptops (most likely all Sony LEDs laptop displays) couldn't use the lowest brightness setting because the sony-laptop.c allows only eight level instead of nine possible in this series. I use a patch to make all nine level accessible but it would break brightness for other Sony laptops. The current sony-laptop implementation has the brightness value 0 but this is actually a 1 within the deprecated sony-acpi implementation and for the TX series. Steps to reproduce: 1. increase brightness to maximum 2. check that /sys/class/backlight/sony/brightness shows only 7 instead of 8
Created attachment 16936 [details] my patch which fixes the problem for the TX series Just for the records my patch which would most likely break brightness for other Sony laptops.
Created attachment 16937 [details] DSDT.dsl
Created attachment 16938 [details] dmidecode output
Any news about this bug. This still seems to be an issue at least with 2.6.31. Since many Sony laptops now have a LED display I think they also might have this bug.