Dell XPS 13 ultrabook freezing on battery [SOLVED}

[ShadowHawkBV]

I've run into a problem recently. with my ultra-book freezing up when I run it on battery. It unmounts then remounts the root SSD as read-only. The trackpad continues to work - I can move the mouse all over, but I cannot click on anything, nor can I change to a virtual terminal until the system unfreezes, by then I cannot do anything as the drive is read-only. I am assuming that this has been caused by a kernel or program change in the last month or so. I update my system every-day, but only restart it infrequently. For the most part, I just suspend it. This means that I cannot even verify which kernel might have been the cause. The prior kernel 4.12.4 did not have this problem, but I cannot count how many updates have occurred between 4.12.4 and 4.12.7 when I rebooted to find the issue. Subsequent kernels have also had the same problem, but since I don't see anything on google about it being an issue, I'm assuming its not the kernel. My first step was disabling the power management in KDE 5. It has had no effect.

I looked in kern.log and there are a number of ACPI errors.

[ShadowHawkBV]

If it matters, the system freeze also occurs a short timer later (30-45min) if the power is disconnected and immediately reconnected after the system hiccups (Mouse moves, but cannot click on anything). The terminal has this :

[albright]

Although it is probably not the same issue, your
symptoms are very similar to ones I ran into
on a thinkpad T440s

if /sys/class/scsi_host/host*/link_power_management_policy

went from max_performance to min_performance and back
when unplugging / plugging into AC power I would get the
reset to read only

my solution was to use power management tools to forbid
min_perf (medium_perf seemed OK)

Just a thought ...
_________________
.... there is nothing - absolutely nothing - half so much worth
doing as simply messing about with Linux ...
(apologies to Kenneth Graeme)

[ShadowHawkBV]

It sounded like a plausible idea, so I went into the /etc/laptop-mode/conf.d and amended the settings to medium or 25%. Same problem. I ran top before removing the power cable after a fresh boot, and the top programs became:
rb_producer
rb_consumer
laptop_mode
org_kde_powerde

rb_prod/con is the ring buffer stress tester from the kernel.
laptop_mode is the service from laptop-mode-tools
org_kde is the powerdevil for KDE? It's turned off for doing anything while the laptop is on battery in the settings.
_________________
This space for rent... Well maybe to give away.. Heck.. i'll pay you to take it.

Lost Linux Neophyte
Intel i7-1065G7
Intel i7-8565U
Intel Atom Cherry Trail
AMD Phenom(tm) II X4 955
Pure 64bit frustration

[ShadowHawkBV]

I rolled back to kernel gentoo-sources-4.12.5 and the freezing issue has disappeared. I appears that something was changed in 4.12.6+ that conflicts with something in the Dell XPS13 going to battery power. I used the exact config file from the 4.12.9 kernel and did the normal