Video PM Methods

[Stefan Seyfried]

On Wed, May 17, 2006 at 10:35:02AM +0100, Richard Hughes wrote:
> On Tue, 2006-05-16 at 15:15 -0400, Peter Jones wrote:

> I figure if the video card is a *specific* device:subdevice from a
> specific vendor, then the pm resume tweaks would be the same between
> laptop vendors, or is that not a valid assumption?

I don't think so. I have seen ATI Radeon RV250 in ThinkPads just working
fine with /proc/sys/kernel/acpi_video_flags=3, but in a Dell D600 they
need VBE_POST|VBE_SAVE and may not use a framebuffer. I am not sure that
they have the exact same PCI id, but it clearly depends on the BIOS more
than on the chip.

What we could do is a 2 stage setup:
- match the machines we know and do what is configured for them.
- if we do not know them, match on the chip and do a "best practice"
  for the chip. E.g. most i915 i have seen worked happily with
  acpi_video_flags=3, many new ATIs do not work with framebuffer, but
  need VBE_POST|VBE_SAVE, so we could "guess" what will work. If this
  guessed value is used, issue a loud honking warning into syslog before
  suspend and tell the users how to check their machine and where to
  report success. That is how the s2ram whitelist grows every day.

> p.s. I'm thinking of writing a python script something like this in the
> future (for power users who know the existing resume settings):
> 
> <script gets output from lshal>
> [ x ] Do you have to use vbetool post
> [ x ] Do you have to use radiontool

BTW: everybody using radeontool should probably apply my patches to get
rid of the "lspci" usage and output parsing. Without those patches, 
radeontool will happily "switch off the light" on ATI motherboard chipsets.

Patches available either in the factory source rpm or (soon) on
ftp.suse.com:/pub/people/seife/radeontool/

> And script send to various development m/l's.
> 
> This way we can start getting the list of cards into CVS so this "just
> works" for as many ppl as possible for the next release.

It might be a good idea, but have them report exact configuration
(running on which framebuffer? Did it only work from X or also from
 console? exact kernel version? etc., can all be done by the script).
-- 
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