Created attachment 102095 [details]
dmesg

Hello everybody.

I'm using a ThinkPad T420 with Optimus. Since 3.15 the boot hangs during KMS,
when I use the discrete card (GF119M [Quadro NVS 4200M]). With the Intel card
or Optimus, the system boots. Though I see those message from the kernel, also
after standby:
  nouveau E[    PBUS][0000:01:00.0] MMIO read of 0x00000000 FAULT at 0x002140 [
!ENGINE ]

When I try to use the Nvidia card via PRIME with, the xserver crashes.

I tested the PRIME way with:
  xrandr --setprovideroffloadsink nouveau Intel
  DRI_PRIME=1 glxgears