Re: Suspend/resume with i915.

On Thu, Jan 22, 2015 at 12:02:01PM +0100, Edward Tomasz Napiera??a wrote:
> I'm trying to fix resume on my T61, broken by some change several
> months ago; according to pciconf it's 'Mobile GM965/GL960 Integrated
> Graphics Controller (primary)'.  It's running current CURRENT and
> up to date packages.
> 
> Suspend and resume makes Xorg do something weird - there is screen
> corruption, or rather window corruption.  The GNOME 3 desktop looks
> pretty normal, except that gnome-terminal (launched before suspend)
> window looks as if the buffer layout changed underneath it; for example,
> instead of one flashing cursor there are several, horizontally, across
> the window.  New windows are simply black.  No segv.
> 
> Setting kern.vt.suspendswitch=0 makes the behaviour disappear, replaced
> by segmentation faults of gnome-shell.  With stock gdb it looks like this:

At least one big known issue with suspend is that userspace activity
is not stopped, which makes the driver suspend code operating on the
non-steady state of devices.

I committed the facility to stop userspace before suspend, and avg promised
to integrate this into suspend path, but he did not.  You might try to
search mailing lists for reference to his earlier patch.