netdev - Re: [PATCH v2 2/2] wcn36xx: Implement tx

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Date:   Sun, 20 Mar 2022 18:03:10 +0000
From:   Bryan O'Donoghue <bryan.odonoghue@...aro.org>
To:     Edmond Gagnon <egagnon@...areup.com>,
        Kalle Valo <kvalo@...eaurora.org>
Cc:     Benjamin Li <benl@...areup.com>, Kalle Valo <kvalo@...nel.org>,
        "David S. Miller" <davem@...emloft.net>,
        Jakub Kicinski <kuba@...nel.org>, wcn36xx@...ts.infradead.org,
        linux-wireless@...r.kernel.org, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 2/2] wcn36xx: Implement tx_rate reporting

On 20/03/2022 13:21, Bryan O'Donoghue wrote:
> On 18/03/2022 19:58, Edmond Gagnon wrote:
>> +    INIT_DELAYED_WORK(&wcn->get_stats_work, wcn36xx_get_stats_work);
> 
> Instead of forking a worker and polling we could add the relevant SMD 
> command to
> 
> static int wcn36xx_smd_tx_compl_ind(struct wcn36xx *wcn, void *buf, 
> size_t len)
> {
>      wcn36xx_smd_get_stats(wcn, 0xSomeMask);
> }
> 
> That way we only ever ask for and report a new TX data rate when we know 
> a TX event - and hence a potential TX data-rate update - has taken place.
> 
> ---
> bod
> 

Thinking a bit more

- Do the SMD get_stats in the tx completion
   This might be a problem initiating another SMD transaction inside
   of an SMD callback. But is the most straight forward way to
   get the data while avoiding alot of needless polling.

- Schedule your worker from the TX completion
   Again you should only care about gathering the data when you know
   something has happened which necessitates gathering that data
   like TX completion

- Schedule your worker from the RX indication routine
   Seems not as logical as the first two but it might be easier
   to schedule the worker in the RX data handler

Either way, I do think you should only gather this data on an event, not 
as a continuous poll.

---
bod