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Message-ID: <03dace08-3916-4332-bd31-b82b627ae847@quicinc.com>
Date:   Mon, 20 Nov 2023 07:54:27 -0800
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Subject: Re: [PATCH 7/7] wifi: ath12k: set IRQ affinity to CPU0 in case of one
 MSI vector
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To:     Kang Yang <quic_kangyang@quicinc.com>, <ath12k@lists.infradead.org>
CC:     <linux-wireless@vger.kernel.org>
References: <20231120101543.4369-1-quic_kangyang@quicinc.com>
 <20231120101543.4369-8-quic_kangyang@quicinc.com>
From:   Jeff Johnson <quic_jjohnson@quicinc.com>
In-Reply-To: <20231120101543.4369-8-quic_kangyang@quicinc.com>
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On 11/20/2023 2:15 AM, Kang Yang wrote:
> With VT-d disabled on Intel platform, ath12k gets only one MSI
> vector. In that case, ath12k does not free IRQ when doing suspend,
> hence the kernel has to migrate it to CPU0 (if it was affine to
> other CPUs) and allocates a new MSI vector. However, ath12k has
> no chance to reconfig it to HW srngs during this phase, thus
> ath12k fails to resume.
> 
> This issue can be fixed by setting IRQ affinity to CPU0 before
> request_irq is called. With such affinity, migration will not
> happen and thus the vector keeps unchanged during suspend/resume.
> 
> Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0-03427-QCAHMTSWPL_V1.0_V2.0_SILICONZ-1.15378.4
> 
> Signed-off-by: Kang Yang <quic_kangyang@quicinc.com>
Acked-by: Jeff Johnson <quic_jjohnson@quicinc.com>