Video PM Methods

[Stefan Seyfried]

On Wed, May 17, 2006 at 11:20:30AM +0100, Matthew Garrett wrote:
> On Tue, May 16, 2006 at 05:33:04PM -0400, Pat Suwalski wrote:
> 
> > Does anyone know if it's just a rePOSTing issue or something? Could it 
> > really not be rectified in the kernel?
> 
> You can work around it with vesafb to some extent:
> 
> 1) Save the vesa mode number
> 2) Disable the framebuffer (echo 3 >/sys/class/graphics/fb0/state)
> 3) Suspend
> 4) Do whatever POST tricks you want to

With the DELLs (D600, D610, D800, D810) i did not get this far. The machine
just booted instead of resuming. It never got back into the kernel, it
apparently decided to boot instead of resume when still inside the BIOS.

On the HPs (nc6230 for example), anything vbetool, especially 
"vbetool vbestate restore" just hung and failed inside LRMI IIRC, it works
fine with vgacon.

The pattern i see is, that many newer machines with ATI cards only work
reliable with vgacon or vga16fb, but not with vesafb. But not all ATIs,
as the thinkpads are just fine with vesafb and acpi_video_flags=3. So it
clearly depends on the BIOS, not only on the card, which answers the other
question in this thread: PCI IDs are probably not as good as DMI matches
for this purpose.

-- 
Stefan Seyfried                  \ "I didn't want to write for pay. I
QA / R&D Team Mobile Devices      \ wanted to be paid for what I write."
SUSE LINUX Products GmbH, Nürnberg \                    -- Leonard Cohen