Re: [PATCH] wireless: ath10k: Return early in ath10k_qmi_event_server_exit() to avoid hard crash on reboot

[Kalle Valo]

Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx> writes:

> On Tue, Jun 02, 2020 at 01:04:26PM -0700, Brian Norris wrote:
>> On Tue, Jun 2, 2020 at 12:40 PM John Stultz <john.stultz@xxxxxxxxxx> wrote:
>> > On Tue, Jun 2, 2020 at 12:16 PM Brian Norris <briannorris@xxxxxxxxxxxx> wrote:
>> > > On Mon, Jun 1, 2020 at 10:25 PM John Stultz <john.stultz@xxxxxxxxxx> wrote:
>> > > >
>> > > > Ever since 5.7-rc1, if we call
>> > > > ath10k_qmi_remove_msa_permission(), the db845c hard crashes on
>> > > > reboot, resulting in the device getting stuck in the usb crash
>> > > > debug mode and not coming back up wihthout a hard power off.
>> > > >
>> > > > This hack avoids the issue by returning early in
>> > > > ath10k_qmi_event_server_exit().
>> > > >
>> > > > A better solution is very much desired!
>> > >
>> > > Any chance you can bisect what caused this? There are a lot of
>> > > non-ath10k pieces involved in this stuff.
>> >
>> > Amit had spent some work on chasing it down to the in kernel qrtr-ns
>> > work, and reported it here:
>> >   https://lists.infradead.org/pipermail/ath10k/2020-April/014970.html
>> >
>> > But that discussion seemingly stalled out, so I came up with this hack
>> > to workaround it for us.
>> 
>> If I'm reading it right, then that means we should revert this stuff
>> from v5.7-rc1:
>> 
>> 0c2204a4ad71 net: qrtr: Migrate nameservice to kernel from userspace
>> 
>> At least, until people can resolve the tail end of that thread. New
>> features (ath11k, etc.) are not a reason to break existing features
>> (ath10k/wcn3990).
>
> I don't agree with this. If you read through the replies to the bug report,
> it is clear that NS migration uncovered a corner case or even a bug. So we
> should try to fix that indeed.

I'm with Mani, we should try to fix ath10k instead. Hopefully we can
find a fix soon.

Forcing QCA6390 users to use the userspace qrtr-ns would be bad user
experience, I really would want to avoid that.

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