i915: -next: have to switch terms after display goes to sleep

[Dan Carpenter <error27@gmail.com>]

In linux-next 3.1.0-rc2-next-20110819+ when the screen goes to sleep
then the screen doesn't refresh properly until I switch to a
non-graphical TTY and then come back.  It does this every time.

I have set my power management to go to sleep after 1 minute to test
this.  After the back light turns off then the screen doesn't come
back properly.

The gnome tool bar at the top of my screen partly shows up, and the
window outlines are there.  I can click on the terminal icon on my
gnome tool bar and the terminals start, but I just can't see them.

Then when I switch to tty2 and back the screen works properly again.

It's not a huge deal, but I thought I should let you know.

00:02.0 VGA compatible controller: Intel Corporation Core Processor Integrated Graphics Controller (rev 02) (prog-if 00 [VGA controller])
        Subsystem: Samsung Electronics Co Ltd Device c581
        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 40
        Region 0: Memory at fc000000 (64-bit, non-prefetchable) [size=4M]
        Region 2: Memory at e0000000 (64-bit, prefetchable) [size=256M]
        Region 4: I/O ports at 1800 [size=8]
        Expansion ROM at <unassigned> [disabled]
        Capabilities: <access denied>
        Kernel driver in use: i915

regards,
dan carpenter