Re: [2/6] 2.6.21-rc2: known regressions

Pavel Machek
2007-03-09T11:20:24Z

Hi!

> > disabling the following radeonfb options in the .config made resume work
> > again:
>
> In general, don't even *try* to use radeonfb for suspend/resume.
>
> I don't think it has ever worked, except on some very rare laptops
> (largely PPC Macs) where people had enough information to set up the
> PLL's.

It worked ok on thinkpad x32. BIOS did the setup in resume case (with
acpi_sleep=..., anyway), and radeonfb could pick the card up from there.

> I don't think the other framebuffer drivers are much better.
>
> You're better off using the VGA console, and lettign X re-initialize the
> graphics device. That generally at least has a reasonably good chance of
> working.

suspend.sf.net, s2ram there has a long list of tricks. If you invent
new one, please add it there.

> Re-initializing graphics modes really is very hard. You can try with the
> BIOS video hack (I forget the kernel command line to turn it on), but we
> really do end up depending on X doing it better.

...or you can try vbetool; it is similar hack to acpi_sleep=... , but
it works for more people.

> Some day we may have modesetting support in the kernel for some graphics
> hw, right now it's pretty damn spotty.

Yep, that's the way to go.
Pavel

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