[Intel-gfx] Garbage on screen when switching resolution after BIOS post

[meteor]

We are developing a Linux solution. Our platform is using Intel SandyBridge
and its VGA
(kernel 2.6.35.8, 915 KMS driver).

We found system will show garbage at the moment VGA is hand over to OS after
BIOS POST.
The symptom doesn’t happen in WIN 7.
After checking with EE, the LCD_VDD_EN pin is pull low again when boot to
Win 7.
However, this pin is not pull low when boot to Linux.

After BIOS POST, there’s a power reset during driver loading for resolution
pattern sending.
It’s why driver needs to control PCH "L_VDD_EN" for power reset, and the
panel spec suggests to
have VDD power off  for >=500ms.

Please refer to the VDD power monitoring image:
http://imageshack.us/photo/my-images/827/auoi.jpg/

Need help to fix the issue in driver.
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