[Intel-gfx] VT switchless suspend/resume

[Jesse Barnes]

On Mon, 25 Feb 2013 13:31:42 -0800
Jesse Barnes <jbarnes at virtuousgeek.org> wrote:

> On Mon, 25 Feb 2013 16:19:53 -0300
> Paulo Zanoni <przanoni at gmail.com> wrote:
> 
> > Hi
> > 
> > 2013/2/19 Paulo Zanoni <przanoni at gmail.com>:
> > > 2013/2/19 Jesse Barnes <jbarnes at virtuousgeek.org>:
> > >> Updated with the fix from Ville.
> > >
> > > Very briefly tested on SNB (LVDS) and HSW (eDP + DP). Suspend-to-ram +
> > > resume still work.
> > 
> > So, today I looked at the patches I didn't review last week and they
> > all looked correct, so I was ready to give a "Reviewed-by" stamp on
> > all of them. I decided to do one more testing and I noticed that with
> > this series, dmesg gives me some error messages that don't happen
> > without the series. On a SNB machine with LVDS+DP, after resume I get
> > error messages saying that DP link training failed (even though the DP
> > monitor is working).
> > 
> > The dmesg file is attached.
> 
> Hm ugly... any ideas why?  This really shouldn't have affected
> anything; we just do a mode set from the kernel first instead of
> waiting on the VT switch...

Looks like it's trying to restore a 2 pipe config?  Is that correct?
The BIOS re-enabled VGA across suspend/resume too, I guess that would
cause trouble...  but the check code says both CRTCs are disabled at
resume.

So first a DP train appears to fail, then we fail waiting for a pipe to
disable because we try another, single pipe mode set.

Which is the proper config?  One pipe or two?

-- 
Jesse Barnes, Intel Open Source Technology Center