i915 IVB hangup after resume from s2mem since v6.6.x

[Johannes Stezenbach]

On Mon, May 06, 2024 at 09:42:18PM +0200, Lukas Wunner wrote:
> On Mon, May 06, 2024 at 08:43:43PM +0200, Johannes Stezenbach wrote:
> > so, git bisect pointed to:
> > 
> >  commit 701d2054fa317188cd4039c84e72c73254013b23
> >  Author: Thomas Zimmermann <tzimmermann at suse.de>
> >  Date:   Tue Jun 13 13:07:13 2023 +0200
> > 
> >     fbdev: Make support for userspace interfaces configurable
> > 
> >     Add Kconfig option CONFIG_FB_DEVICE and make the virtual fbdev
> >     ...
> > 
> > I think nothing on my system uses /dev/fb*, thus I had disabled
> > CONFIG_FB_DEVICE. Everything worked, only suspend/resume broke.
> > I can confirm v6.8.9 with CONFIG_FB_DEVICE=y works fine.
> 
> A user-visible regression like this is always sufficient to ask for a
> revert of the offending commit.  It's the commit author's duty to find
> a fix ASAP. If you could file a bug report that would be helpful but
> you've already done more than could be asked from any user.

I don't think it is a regression. A new config option was added
with default=y and I chose to disable it. The results were
unexpected since the Kconfig help text didn't say "can break
suspend/resume with i915" ;-/


Johannes