I was hoping that I've done the trick. The issue is that the "10-laptop-panel-mgmt-policy.fdi" is loaded before "10-sony-laptop-brightness.fdi" (which delete the wrong sysfspath"). Thus There is two solutions : 1- force the evaluation of "10-sony-laptop-brightness.fdi" before the other by changing its order. But it may become non-standard. 2- Second approach is to copy&paste the appropriate part of "10-laptop-panel-mgmt-policy.fdi" into "10-sony-laptop-brightness.fdi". I will search throught the specifications if solution 1 can be done without becoming non-standard. The thing to understand here is that the module "sony-laptop" (which give you keys, etc. on VAIOs) also create a backlight device with "linux.sys_fspath". This "sys_fspath" only work on old graphic cards. "10-sony-laptop-brightness.fdi" remove this "linux.sys_fspath" since it is the wrong one for our models. 2009/8/2 Alex