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Date:   Mon, 21 Aug 2023 15:27:52 +0200
From:   Johan Hovold <johan@kernel.org>
To:     Manikanta Pubbisetty <quic_mpubbise@quicinc.com>
Cc:     Johan Hovold <johan+linaro@kernel.org>,
        Kalle Valo <kvalo@kernel.org>,
        Jeff Johnson <quic_jjohnson@quicinc.com>,
        Bjorn Andersson <quic_bjorande@quicinc.com>,
        Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>,
        Konrad Dybcio <konrad.dybcio@linaro.org>,
        ath11k@lists.infradead.org, linux-wireless@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Revert "Revert "wifi: ath11k: Enable threaded NAPI""
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References: <20230809073432.4193-1-johan+linaro@kernel.org>
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On Thu, Aug 10, 2023 at 10:03:55AM +0530, Manikanta Pubbisetty wrote:
> 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.

> > > What is the chip that Lenovo Thinkpad X13s is having?
> > 
> > It's a WCN6855 (QCNFA765).
> 
> WCN6855 & QCN9074 share the same driver code base since both being PCIe
> devices. One working and another not working seems to be surprising. Do you
> have a dmesg log when this problem occurred?

I can't access the logs after I hit this bug (e.g. as there are no
interrupts received from the keyboard) but when I trigger this from the
console, there is nothing logged when the hang happens.

Later, secondary errors are logged from other drivers that are no longer
receiving interrupts either, and RCU detects a stall as I mentioned
elsewhere.

Johan