Comment # 34 on bug 1207948 from Takashi Iwai

The hibernation problem seems known for the upstream devs, but the feature
hasn't been implemented properly yet.

I took a quick look now, as we've received a test machine here, too; it's not
trivial to fix this, unfortunately.  ath11k driver has a complex layer,
communicating from a PCI device over MHI bus via Qualcomm SoC.  And the
hibernation code is missing at many places in those pictures.  Let's hope that
the upstream devs will fix it eventually later.

Meanwhile, we can put a patch to reduce the default timeout from 90 seconds to
a smaller one, e.g. 5 seconds, for avoiding a kernel panic.

And, a simple workaround for this is just to unload and reload at
hibernation/resume.  You can put a script like below to
/usr/lib/systemd/system-sleep directory (with exec bit set).