Just a comment about a similar problem I'm having...
I have a PS/2 mouse/keyboard to USB adapter (USB ID 13ba:0017). The PS/2 keyboard works fine in the Grub menu (presumably this is the BIOS emulation working here) but once the kernel starts it doesn't work at all. This is for typing in a LUKS passphrase (this happens in the initrd), once the system has started (ie. press ctrl+shift+f1 on the laptop keyboard, the other one doesn't work) nor does it work in gdm. However, the PS/2 mouse attached to it works fine (this mouse does USB also via an adapter).
I also have a docking station with PS/2 ports on it, and that works fine with a PS/2 keyboard provided I attach the laptop before I turn it on. (I don't know how this docking station works, but it might have USB ID 0930:0403 or it might send the PS/2 signals straight to the docking connector.)
Just a comment about a similar problem I'm having...
I have a PS/2 mouse/keyboard to USB adapter (USB ID 13ba:0017). The PS/2 keyboard works fine in the Grub menu (presumably this is the BIOS emulation working here) but once the kernel starts it doesn't work at all. This is for typing in a LUKS passphrase (this happens in the initrd), once the system has started (ie. press ctrl+shift+f1 on the laptop keyboard, the other one doesn't work) nor does it work in gdm. However, the PS/2 mouse attached to it works fine (this mouse does USB also via an adapter).
I also have a docking station with PS/2 ports on it, and that works fine with a PS/2 keyboard provided I attach the laptop before I turn it on. (I don't know how this docking station works, but it might have USB ID 0930:0403 or it might send the PS/2 signals straight to the docking connector.)