Comment 11 for bug 772925

Same issue for me. I've got an acer timeline 5810TZ with an ati 4300 and an intel integrated. As the vga_switcheroo does not work properly, I'm using a patch which desactivate the ati card so the bug happens on the intel chipset.

When I close my computer,sometimes after a while when I reopen it, I can enter my password in order to unlock the screen, I find the same screen I left but nothing respond except the mouse. I can go to another tty, do what I want in tty as restart gdm or restart the computer.
Sometimes, when I reopen the computer, the screen is black with backlight and I cannot enter my password. I think it's the same bug.

>> lspci | grep VGA
     00:02.0 VGA compatible controller: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller (rev 07)
     01:00.0 VGA compatible controller: ATI Technologies Inc M92 LP [Mobility Radeon HD 4300 Series] (rev ff)

00:02.0 VGA compatible controller: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller (rev 07) (prog-if 00 [VGA controller])
 Subsystem: Acer Incorporated [ALI] Device 023f
 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-
 Latency: 0
 Interrupt: pin A routed to IRQ 44
 Region 0: Memory at e0000000 (64-bit, non-prefetchable) [size=4M]
 Region 2: Memory at d0000000 (64-bit, prefetchable) [size=256M]
 Region 4: I/O ports at 5110 [size=8]
 Expansion ROM at <unassigned> [disabled]
 Capabilities: <access denied>
 Kernel driver in use: i915
 Kernel modules: i915