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

[govinds@codeaurora.org]

Hi Mani,

On 2020-06-03 05:57, Manivannan Sadhasivam wrote:
> 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@linaro.org> 
>> wrote:
>> > On Tue, Jun 2, 2020 at 12:16 PM Brian Norris <briannorris@chromium.org> wrote:
>> > > On Mon, Jun 1, 2020 at 10:25 PM John Stultz <john.stultz@linaro.org> 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.
> 
> Govind: Did you get chance to work on fixing this issue?
> 

I have done basic testing by moving msa map/unmap from qmi service 
callbacks to init/de-init path.
I will send patch for review.
Reason for del_server needs to investigated from rproc side.

> Thanks,
> Mani
> 
>> 
>> Brian

Thanks,
Govind