Re: 2.6.25-rc7/8: Another resume regression

[Mark Lord <lkml@rtr.ca>]

Mark Lord wrote:
> Hi,
> 
> Okay, USB now works fine on resume after fixing the iaa_watchdog issue.
> 
> But twice now, once before that fix, and again just a minute ago,
> my machine has failed completely to resume after suspend-to-RAM.
> 
> Again, resume here is 100% reliable in 2.6.24 and earlier.
> 
> Symptoms: the usual:
> 
>  -- 2.6.25-rc8 (and -rc7 earlier), plus USB fix.
>  -- not reproduceable on demand.
>  -- black screen of death -- no backlight, no kernel messages.
>  -- no hard drive activity.
>  -- no alt-sysrq-anything.
>  -- 5 second hold of the power button to poweroff and then recover.
> 
> Not much info to go on, but it's worth knowing there's an issue here 
> somewhere.
..

Mmmm... Now that 2.6.25-rc* is usable here, there's another symptom
that's been happening regularly enough that it's got to be a regression
of some sort.

This machine has an ATI X1400 video card, which doesn't work with any
open source X server that I know of.  Maybe latest RadeonHD would work
but it didn't when I tried it in January.

So I'm using the ATI binary fglrx X server, but without their kernel module,
so no 3D acceleration (fine.. only affects Google Earth, really).

Now.. on 2.6.25, after a suspend/resume cycle (or three), the framebuffer
frequently starts going wonky.  "snowy" pixels appear, and stay.
Just a moment ago here, the entire background changed to zebra stripes.

And so on..  Peculiar stuff.

I'm wondering if something to do with video mode switching,
or video register save/restore, has changed since 2.6.24.
Because it's broken in 2.6.25, yet works fine in all earlier kernels.

???