Thinkpad T410: resume broken

[Alexey Dokuchaev]

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? :-)

If "having VESA is supposed to be like using 'hw.acpi.reset_video=1' on
9", it should not hurt (I recall having to hw.acpi.reset_video=1 in early
stable/[67] days, but no longer for quite a long time with stable/8).

Admittedly, the whole situation with i915kms, vesa.ko, et al. looks quite
confusing, while suspend/resume works *worse* than with stable/8 and pre-
KMS.  Table of known laptops on wiki page [1] is hardly helpful unless it
has your laptop of interest; IMHO it would benefit a lot more from listing
common symptoms and mitigation/fixes for them (including VESA, sysctl vars,
kernel options, etc).

> ACPI_PM setting to the kernel module along with removing VESA would seem
> like your best bet, but I see in follow-ups that that wasn't completely
> reliable.  However, you can try using ACPI_PM with syscons, no need to
> use vt.

What are indications for use of ACPI_PM option?  As for removing VESA,
I've found that my laptop resumes more willingly with i915kms.ko *and*
vesa.ko than without vesa.ko (could only? be loaded from loader.conf):
with both modules loaded it takes only three presses of power button to
get back from suspend, while without vesa.ko it's a lottery, and often
power-cycling is required to get things back to working -- any ideas on
why would that be?

Needless to say, suspend/resume worked nearly flawlessly under stable/8
and stable/7 FWIW.

./danfe

[1] https://wiki.freebsd.org/SuspendResume