Re: Thinkpad T410: resume broken

On Thu, Feb 18, 2016 at 06:50:34AM -0800, John Baldwin wrote:
> On Thursday, February 18, 2016 08:13:38 PM Alexey Dokuchaev wrote:
> > On Sat, May 17, 2014 at 08:20:03AM -0400, John Baldwin wrote:
> > > VESA needs to be removed for i915kms, but I've no idea if it needs to be
> > > removed for Nvidia.  The video reset code was reworked in 10 so that
> > > having VESA is supposed to be like using 'hw.acpi.reset_video=1' on 9,
> > > but in theory it works more often.
> > 
> > This (VESA needs to be removed for i915kms) is news to me: I don't see it
> > mentioned in UPDATING, and "options VESA" presents in -CURRENT's (post-KMS
> > era) GENERIC kernel config.  So what's the real deal here? :-)
> 
> This is an old mail you are responding to.  You no longer need to remove
> VESA for kms.

Ah OK, that would explain it, thanks.

> vesa.ko shouldn't be working with KMS.  KMS turns off the legacy VGA
> emulation in the hardware when it starts which prevents VESA from working
> (VESA requires the legacy VGA interface).

Hmm, could this explain why vesa.ko can be loaded from loader.conf, but
not via kldload(8)?  OTOH, kldload'ing it later does not seem to work
(ir)regardless of whether i915kms.ko is loaded or not...

> I never have to hit the power button more than once to resume on a laptop
> where resume works though.
> 
> (True on my X220 and on a T440 both with Intel or Radeon graphics (all
> using KMS).

I'm about to try fresh -CURRENT on some HP AMD APU-based laptops, hence
I'll ask: do aforementioned laptops suspend/resume without issues in X11
or on the naked console as well?  (In a shop, I could only quickly test
our X11-less memstick image.)

> > Needless to say, suspend/resume worked nearly flawlessly under stable/8
> > and stable/7 FWIW.
> 
> If it worked here, then this means you could try using sc(4) + the old drm
> (not drm2).  This means your laptop is old enough to still turn the LCD panel
> back on in its BIOS during resume like my HP netbook.  However, I don't know
> for how much longer Xorg will support the older drm (if it even does now).

Well, technically, my laptop *does* resume with vt(4) + i915kms, just it
takes a lot of power button hits and quite some time (up to several minutes),
unless it dies somewhere during the process.  I'll retest it against
GENERIC and report in a separate email.  On a related note, how does one
configure sc(4) with old drm (vs. drm2) shall I need to try that?

> FWIW, the HP netbook resumes fine with KMS as well for me.  One caveat
> though is that if you are using vt(4) and haven't yet loaded KMS it won't
> resume (due to vt(4) not having the equivalent of VESA).  With sc(4) the
> netbook was always able to resume.

Right.  So far, I've been booting, kldloading i915kms.ko, zzz(8), resume.
No X.Org was involved -- given how fragile suspend/resume is ATM, I'd like
to iron out the issues with the pure console first.

./danfe