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Message-ID: <d012ddc8-3578-43da-9787-e44dcc4e7206@quicinc.com>
Date: Wed, 29 Nov 2023 07:35:44 -0800
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Subject: Re: [PATCH v2 3/3] wifi: ath12k: change MAC buffer ring size to 2048
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To: Baochen Qiang <quic_bqiang@quicinc.com>, <ath12k@lists.infradead.org>
CC: <linux-wireless@vger.kernel.org>
References: <20231129020414.56425-1-quic_bqiang@quicinc.com>
 <20231129020414.56425-4-quic_bqiang@quicinc.com>
From: Jeff Johnson <quic_jjohnson@quicinc.com>
In-Reply-To: <20231129020414.56425-4-quic_bqiang@quicinc.com>
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On 11/28/2023 6:04 PM, Baochen Qiang wrote:
> For WCN7850, there is a SRNG named MAC buffer ring, i.e.,
> dp->rx_mac_buf_ring. During initialization, it is setup
> by host and then under control of firmware. During RX
> process, firmware fetches buffers from
> dp->rx_refill_buf_ring to fill that MAC buffer ring,
> and those buffers are taken by RXDMA to carry real WLAN
> frames received from air.
> 
> Currently a low RX throughput is observed. Checking
> firmware log, lots of errors are reported by MAC buffer
> ring, complaining that it is running out of buffers,
> which further indicates that RXDMA is suffering from
> starvation. Currently the size of dp->rx_mac_buf_ring
> is configured as 1024. After changing it to 2048, those
> error messages are reduced, and a 6.4% increase is seen
> in peak throughput. Note that 2048 is an empirical
> value. It is chosen here because the RX throughput
> meets our expectation after the change.
> 
> This change only applies to WCN7850 since other
> chips don't have a MAC buffer ring.
> 
> Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0-03427-QCAHMTSWPL_V1.0_V2.0_SILICONZ-1.15378.4
> 
> Signed-off-by: Baochen Qiang <quic_bqiang@quicinc.com>
Acked-by: Jeff Johnson <quic_jjohnson@quicinc.com>