Re: [PATCH] Revert "Revert "wifi: ath11k: Enable threaded NAPI""

[Manikanta Pubbisetty]

On 8/9/2023 2:46 PM, Johan Hovold wrote:
> On Wed, Aug 09, 2023 at 02:32:37PM +0530, Manikanta Pubbisetty wrote:
> > On 8/9/2023 1:04 PM, Johan Hovold wrote:
> > > This reverts commit d265ebe41c911314bd273c218a37088835959fa1.
> > >
> > > Disabling threaded NAPI causes the Lenovo ThinkPad X13s to hang (e.g. no
> > > more interrupts received) almost immediately during RX.
> > >
> > > Apparently something broke since commit 13aa2fb692d3 ("wifi: ath11k:
> > > Enable threaded NAPI") so that a simple revert is no longer possible.
> >
> > This is getting as weird as it would get :)
> >
> > > As commit d265ebe41c91 ("Revert "wifi: ath11k: Enable threaded NAPI"")
> > > does not address the underlying issue reported with QCN9074, it seems we
> > > need to reenable threaded NAPI before fixing both bugs properly.
> >
> > It seems that the revert has actually solved the issue reported with
> > QCN9074.
> >
> > https://bugzilla.kernel.org/show_bug.cgi?id=217536
>
> Sure, but it's only a workaround as the underlying cause has not been
> identified.
>
> > We were trying to reproduce the problem on X86+QCN9074 (with threaded
> > NAPI) from quite some time, but there is no repro yet.
> >
> > Actually, enabling/disabling threaded NAPI is a simple affair; I'm
> > wondering to hear that interrupts are blocked due  to not having
> > threaded NAPI.
>
> It sounds to me like the driver's locking is broken if moving to softirq
> processing hangs the machine like this. But I have not had time to try
> to try to track it down besides verifying that reenabling threaded NAPI
> makes the problem go away.
>
> > What is the chip that Lenovo Thinkpad X13s is having?
>
> It's a WCN6855 (QCNFA765).

Also it is worth to give a try with this patch here 
https://patchwork.kernel.org/project/linux-wireless/patch/20230601033840.2997-1-quic_bqiang@xxxxxxxxxxx/ 
. This seems to be fixing some known interrupt issue on WCN6855. Could 
you pls give a try?

Thanks,
Manikanta