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Re: ThinkPad - suspend-to-RAM intel-x86 issues and tests

On 2018/11/28 22:12, SAITOH Masanobu wrote:
On 2018/11/28 14:18, Masanobu SAITOH wrote:
Hi, David.

On 2018/11/28 6:09, David Brownlee wrote:
On Tue, 27 Nov 2018 at 18:10, David Brownlee <> wrote:

On Tue, 27 Nov 2018 at 08:27, Masanobu SAITOH <> wrote:

    Hi, David.

On 2018/11/26 6:11, David Brownlee wrote:
I've bisected the changes against the github src copy, and it looks like the suspend/resume issue is related to the following commit:

commit 0fe469276f49bf0dc003300e0b8a35a80b7b246d (HEAD)
Author: jdolecek <>
Date:   Mon Oct 22 20:57:07 2018 +0000

       enable MSI support where available, blatantly copied from jmcneill's msk(4)

I tried building from HEAD with just that one commit reverted, and my T420s suspends and resumes again!

iwn0 is still non responsive after resume and wm0 will not pick up an IP via dhcpcd, but the disk responds :-p

    (Note that I'm not familiar with suspend/resume though...)

    Our pci_suspend()/pci_resume() copy only first 16 bytes of each PCI
config space. Other OSes copy some other control registers and
MSI/MSI-X capability area.

    Could you dump all PCI config space both before and after suspend with:

and put the two output somewhere? Diffing the two output will teach
us what we have to do.

    Thanks in advance.

Let me just install to a USB stick to give me a working filesystem
from which to run pcidump after resume :-p

Collecting a pre-suspend dump was easy, but getting post-resume turned
out to be a little more involved :)
- root on wd0 on ahcisata - times out on resume
- root on sd0 on usb on xhci - times out on resume
- root on sd0 on usb on uhci - loses the root filesystem mount point on resume
- install image - doesn't have the libs to run pcictl
- install image, then chroot to mfs with extracted base - suspends but
video does not come back (no drm)
- root on wd0, then chroot to mfs with extracted base, suspend &
resume, then mount sd0 on usb on uhci to save data - \o/

After all that it occurred to me I could have probably run the
suspend/resume with an older NetBSD version where MSI was not being
used. Still, interesting puzzle to try, and useful technique to stash.

Files for the ThinkPad T420s:

The diff says we should save/restore MSI table.
We also should save/restore some other registers.

  Give me one or two days to resolve the problem.

  Please try the following diff:

Even if I use this change with Thinkpad X220, it doesn't recover from

 But, my X61 survived from suspend with this patch!


Thanks for looking at this!


                SAITOH Masanobu (

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