I have installed Ubuntu 11.10 64 bit edition on my Lenovo Thinkpad T520. At that time, I had turn off the discrete graphics through the BIOS settings to preserve battery life. Now, I want to enable the discrete graphics again, but when I do, I cannot increase the resolution of the screen higher than 1024:768.

I checked in the System Settings->Displays and it shows my screen as being "Unknown". I read on how to install the nouveau driver, but can't use the procedure explained in https://help.ubuntu.com/community/BinaryDriverHowto/Nvidia as there is nothing in the "Additional Drivers" dialog box. How can I install the nouveau driver?

Here is the output of $lspci -d10de: -vvvnn

01:00.0 VGA compatible controller [0300]: nVidia Corporation Device [10de:1057] (rev a1) (prog-if 00 [VGA controller])

Subsystem: Lenovo Device [17aa:21cf]

Control: I/O+ Mem+ BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-

Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-

Interrupt: pin A routed to IRQ 16

Region 0: Memory at f2000000 (32-bit, non-prefetchable) [size=16M]

Region 1: Memory at e0000000 (64-bit, prefetchable) [size=256M]

Region 3: Memory at f0000000 (64-bit, prefetchable) [size=32M]

Region 5: I/O ports at 5000 [size=128]

Expansion ROM at f3080000 [disabled] [size=512K]

Capabilities: <access denied>

Kernel modules: nouveau, nvidiafb