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Subject: Re: How to use the rate control in mac80211?
From:   Johannes Berg <johannes@sipsolutions.net>
To:     Bitterblue Smith <rtl8821cerfe2@gmail.com>,
        "linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>
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Date:   Sun, 23 Oct 2022 17:53:00 +0200
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Hi,

> I thought it's like this:
> 1) don't set HAS_RATE_CONTROL

yes

> 2) tell the chip to use the rate from tx_info->control.rates[0]

I'd prefer you didn't, that's also very limited :-)

> 3) report if the frame was acked or not

Kind of.

It'd be better if new drivers used sta_rate_tbl_update method, so it'd
be something like

 1) don't set HAS_RATE_CONTROL
 2) implement sta_rate_tbl_update(), using the table of rates given
    there to instruct the device to transmit frames at those rates
 3) on TX success/failure, fill in a struct ieee80211_rate_status array=C2=
=A0
    that indicates which rates were used and how many times until the
    eventual success or failure; this is in struct ieee80211_tx_status
 3) alternatively, fill in the tx_info rates array the same way and
    report it that way, but that's less flexible


johannes