suspend/resume on Lenovo X1 (regression from reports on wiki)

[John Baldwin]

On Wednesday, September 04, 2013 3:14:32 pm Bengt Ahlgren wrote:
> Jung-uk Kim <jkim at FreeBSD.org> writes:
> 
> > On 2013-09-04 09:29:35 -0400, John Baldwin wrote:
> >> On Tuesday, September 03, 2013 6:58:55 pm Jung-uk Kim wrote:
> >>> On 2013-09-03 16:47:47 -0400, John Baldwin wrote:
> >>>> Even with that hacked so I force vgapm0 and dpms0 to attach, I 
> >>>> still can't resume in console mode, ...
> >>> 
> >>> What happens?  Does it panic, hang, or just no backlight?
> >> 
> >> Just no backlight.  It resumes fine and if I do it in multiuser I 
> >> can ssh in, etc.  It's just the backlight that doesn't resume.  I
> >> was hopeful dpms.ko would fix that, but it didn't. :(
> >
> > Ah, that's a well-known problem and we cannot fix it without help of
> > machine-specific code, e.g., drm1/drm2.  Actually, both acpi_video and
> > dpms try to restore video settings but nothing worked for Intel GPUs +
> > LVDS + LCD panel AFAIK.
> >
> >> I think i915drm has code to specifically turn on the backlight as
> >> I get some weird error message in the kernel console about a
> >> timeout trying to turn the panel off during suspend when I'm in X.
> > So, I guess it has an ordering issue.  If my memory serves, drm1 was
> > okay with vesa, however.  I *think* it accidentally worked because of
> > automatic VT-switching, which is still broken for KMS.
> 
> Yes, perhaps, but there is also the sysctl hw.acpi.reset_video which I
> have enabled on my older hardware (TP X40 running 8.3-REL and an old
> Xorg server) for it to work properly.  (I however have some faint memory
> that reset_video might a no-op these days, or?)  In this old mail
> regarding reset_video, there is a thought that it could be good with
> "more" reinitialisation:
> 
> http://lists.freebsd.org/pipermail/freebsd-acpi/2006-July/002959.html
> 
> I however have one datapoint that I think contradicts John's thought.
> This is on a X201 with stable/9 and no options VESA.  I first just
> booted up and stayed in text console, suspended and resumed.  No
> backlight, of course, and also no content on the LCD, it is completely
> black.  Then, I started Xorg with KMS.  Still no backlight, but you can
> see that the LCD is driven with the desired content, which is one step
> forward.  Finally, I suspended and resumed, but no difference, the
> backlight is still off.  Xorg/KMS didn't manage to turn the backlight
> on, so the text console suspend/resume cycle managed to persistently
> turn the backlight off.

Try starting X before you suspend the first time.  For me resume works
fine if I do that.

> One more thing, the kernel logs this at resume directly after the
> devices are powered on (transition to D0), but I have no idea whether it
> is relevant:
> 
> Sep  2 19:57:21 bit kernel: error: [drm:pid1904:intel_lvds_enable] *ERROR* 
timed out waiting for panel to power off

I see this even when resume works fine.

-- 
John Baldwin