ath11k: crashes with 1 MSI vector, workaround disable MHI M2 state

[wi nk]

On Mon, Dec 21, 2020 at 6:16 PM Kalle Valo <kvalo at codeaurora.org> wrote:
>
> wi nk <wink at technolu.st> writes:
>
> > Another interesting note is that the laptop only seems to attempt the
> > transition when it's plugged into the charger (see my mp4s for more
> > info). If I boot the laptop on battery and bring up the adapter, it
> > never attempts the transition beyond m0 either.
>
> This is so weird to me, what could cause it?
>
> If you boot the laptop on battery but after the boot connect it to the
> charger, what does it do? I'm wondering f this is some boot state
> problem/feature or does the behaviour change runtime.
>
> --
> https://patchwork.kernel.org/project/linux-wireless/list/
>
> https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches

The behavior is changing during runtime as best I can tell.  In some
of my earlier videos you can see the behavior directly:

Boot 1: https://github.com/w1nk/ath11k-debug/blob/master/PXL_20201209_004643171.mp4
- The machine and driver has been online and stable for 5 minutes (as
seen in htop/ping), plugging in the charger causes the state
transition which results in a hang after a few seconds

Boot 2 : https://github.com/w1nk/ath11k-debug/blob/master/PXL_20201209_005346443.mp4
- Same set up (although the machine had been up for 6 minutes at that
point) and failure as boot 1. The machine hard locks instantly this
time, as opposed to the stuttering you can see in boot 1.

(video mirror is the google drive link earlier in the thread).  If you
watch those first 2 boots, the MHI state changes as a direct result of
me plugging the usb-c cable into the laptop.  What I thought was
bluetooth interfering early on in my debugging was actually an
artifact of which room I was working in and if my charger/headphones
were available.   In the boot videos where the driver crashes
immediately, the charger is already plugged in , so the adapter
attempts the state transition right after the driver initializes.