Foi resolvido instalando o bumblebee com nvidia-346. A solução detalhada está disponível no link
Eu tenho o Ubuntu 15.04 instalado no laptop Lenovo Z5070. Para a Nvidia 840m eu tenho nvidia-346 instalado. Ao acordar do sono, recebo o seguinte erro em uma tela preta
drm: hsw_uncalimed_reg_clear Error unknown claimed register before writing to c7204
drm: hsw_unclaimed_reg_check
Eu ssh em meu sistema nesse estado. Aqui está a cauda de xorg.0.log
[ 70.924] (II) modeset(G0): EDID vendor "CMN", prod id 5579
[ 70.924] (II) modeset(G0): Printing DDC gathered Modelines:
[ 70.924] (II) modeset(G0): Modeline "1920x1080"x0.0 136.62 1920 1964 1992 2070 1080 1082 1086 1100 -hsync -vsync (66.0 kHz eP)
[ 70.924] reporting 3 4 37 280
[ 71.376] reporting 3 4 37 280
[ 73.380] (II) XKB: reuse xkmfile /var/lib/xkb/server-7C75F152E85183199599C3E0B919739C0EE668AA.xkm
[ 76.529] reporting 3 4 37 280
[ 77.733] reporting 3 4 37 280
[ 77.834] (II) modeset(G0): EDID vendor "CMN", prod id 5579
[ 77.834] (II) modeset(G0): Printing DDC gathered Modelines:
[ 77.834] (II) modeset(G0): Modeline "1920x1080"x0.0 136.62 1920 1964 1992 2070 1080 1082 1086 1100 -hsync -vsync (66.0 kHz eP)
[ 77.834] reporting 3 4 37 280
[ 77.857] reporting 3 4 37 280
[ 110.090] reporting 3 4 37 280
[ 121.436] reporting 3 4 37 280
[ 167.116] reporting 3 4 37 280
[ 178.272] reporting 3 4 37 280
[ 217.841] reporting 3 4 37 280
[ 243.717] reporting 3 4 37 280
[ 1345.073] reporting 3 4 37 280
[ 1533.403] reporting 3 4 37 280
[ 1537.357] (WW) NVIDIA(GPU-0): Failed to enter interactive mode.
[ 1537.357] (II) NVIDIA(0): Setting mode "NULL"
[ 1537.358] (EE) NVIDIA(0): Failed to allocate primary buffer: error
[ 1537.358] (EE) NVIDIA(0): *** Aborting ***