Re: [PATCH v4 1/3] wifi: ath12k: report station mode transmit rate

[Kalle Valo <kvalo@kernel.org>]

Lingbo Kong <quic_lingbok@quicinc.com> writes:

> Currently, the transmit rate of "iw dev xxx station dump" command
> always show an invalid value.
>
> To address this issue, ath12k parse the info of transmit complete
> report from firmware and indicate the transmit rate to mac80211.
>
> This patch affects the station mode of WCN7850 and QCN9274.
>
> After that, "iw dev xxx station dump" show the correct transmit rate.
> Such as:
>
> Station 00:03:7f:12:03:03 (on wlo1)
>         inactive time:  872 ms
>         rx bytes:       219111
>         rx packets:     1133
>         tx bytes:       53767
>         tx packets:     462
>         tx retries:     51
>         tx failed:      0
>         beacon loss:    0
>         beacon rx:      403
>         rx drop misc:   74
>         signal:         -95 dBm
>         beacon signal avg:      -18 dBm
>         tx bitrate:     1441.1 MBit/s 80MHz EHT-MCS 13 EHT-NSS 2 EHT-GI 0
>
> Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0.c5-00481-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3
> Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.2.1-00201-QCAHKSWPL_SILICONZ-1
>
> Signed-off-by: Lingbo Kong <quic_lingbok@quicinc.com>

[...]

> +static void ath12k_dp_tx_update(struct ath12k *ar, struct hal_tx_status *ts)
> +{
> +	if (ar->last_ppdu_id != 0) {
> +		if (ar->last_ppdu_id == ts->ppdu_id ||
> +		    ar->cached_ppdu_id == ar->last_ppdu_id)
> +			ar->cached_ppdu_id = ar->last_ppdu_id;
> +
> +		ath12k_dp_tx_update_txcompl(ar, ts);
> +	}
> +
> +	ar->last_ppdu_id = ts->ppdu_id;
> +}

A code comment would help a lot. Why is ar->cached_ppdu_id needed here?

And if 'ar->cached_ppdu_id == ar->last_ppdu_id' is true why do then do
'ar->cached_ppdu_id = ar->last_ppdu_id'? The value of ar->cached_ppdu_id
is not changing here (unless I'm missing something).

Also I'm worried about locking. How is access to ar->last_ppdu_id and
ar->cached_ppdu_id protected?

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