I have very strange problem with Dell XPS 13 Laptop (Skylake version). While almost works flawlessly, touchpad has issue with hw.psm.synaptics_support=1
It works only ones! I mean, the first time I add synaptics support and boot xorg - cursor moves, button clicks. After I restart xorg - buttons become unresponsive. button2 event is not registered anymore, button1 event registered maybe 1 time for 10 taps and it can stick in pressed state, leaving touchpad completely unusable.
I recompiled kernel with psm_debug flag = 1 and noticed nothing suspicious. To workaround the issue I must enable-disable device with xinput.
The interesting part is that on enable phase the system hangs until I tap the touchpad.
I tried linux from pen drive - touchpad works, so this is not a hardware problem.
synaptics driver has the same problem, however it survives xorg restart. Touchpad becomes broken after reboot, in broken state Xorg.log is being rapidly filled with synaptics driver attached to psm0 device - like driver attaches to device in endless loop.
I have no idea what information provide - the problem looks completely insane and unique.
CURRENT has the same problem.