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Message-ID: <1796b817-797e-4673-bfee-2f55352c37be@quicinc.com>
Date:   Tue, 21 Nov 2023 08:07:48 -0800
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Subject: Re: [PATCH v2 5/7] wifi: ath12k: add support one MSI vector
Content-Language: en-US
To:     Kang Yang <quic_kangyang@quicinc.com>, <ath12k@lists.infradead.org>
CC:     <linux-wireless@vger.kernel.org>
References: <20231121021304.12966-1-quic_kangyang@quicinc.com>
 <20231121021304.12966-6-quic_kangyang@quicinc.com>
From:   Jeff Johnson <quic_jjohnson@quicinc.com>
In-Reply-To: <20231121021304.12966-6-quic_kangyang@quicinc.com>
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On 11/20/2023 6:13 PM, Kang Yang wrote:
> On some platforms it's not possible to allocate 32 MSI vectors for
> various reasons, maybe kernel configuration, VT-d disabled, buggy BIOS
> etc. So ath12k was not able to use WCN7850 PCI devices on those
> platforms. Add support for one MSI vector to solve that.
> 
> In case of one MSI vector, interrupt migration needs to be disabled.
> This is because when interrupt migration happens, the msi_data may
> change. However, msi_data is already programmed to rings during initial
> phase and ath12k has no way to know that msi_data is changed during run
> time and reprogram again.
> 
> In case of one MSI vector, MHI subsystem should not use IRQF_NO_SUSPEND
> as WCN7850 doesn't set this flag too. Ath12k doesn't need to leave IRQ
> enabled in suspend state.
> 
> 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>