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Message-ID: <c9befe233be586eb2c949f7301784e948c3a6683.camel@sipsolutions.net>
Subject: Re: [RFC 0/4] mac80211: add TPC support in control path
From:   Johannes Berg <johannes@sipsolutions.net>
To:     Jonas Jelonek <jelonek.jonas@gmail.com>
Cc:     linux-wireless@vger.kernel.org, nbd@nbd.name,
        Thomas =?ISO-8859-1?Q?H=FChn?= <thomas.huehn@hs-nordhausen.de>
Date:   Wed, 31 Aug 2022 16:22:09 +0200
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         <467218ec220ea6e36b4222efc5c46e4e350fe1ea.camel@sipsolutions.net>
         <CE871D89-B996-4D8B-8C65-7C53382C30D8@gmail.com>
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Sorry I dropped out of the thread - busy with other stuff. I'll reply to
other mails later.

> I am working on the hwsim support right now, tpc support in hwsim=E2=80=
=99s
> control path is implemented.
> However I encountered a problem in the status path. Hwsim seems to
> hand over to mac80211
> tx-status asynchronously via ieee80211_tx_status_irqsafe only. There,
> the skb is added to
> ieee80211_local->skb_queue and then dequeued in
> =E2=80=98ieee80211_tasklet_handler=E2=80=99 to be passed
> to =E2=80=98ieee80211_tx_status=E2=80=99. For tx rates this is sufficient=
, but there
> is no space left in=20
> ieee80211_tx_info->status to pass the tx-power per packet.
> Please correct me if I missed something in the code.
>=20
> My idea to solve this may be: to use the SKB extension (struct skb_ext
> *extensions) to pass the=20
> tx-power information (and maybe more) for each SKB. Could this be an
> appropriate approach or=20
> do I miss something here? Maybe someone who is much more aware of the
> mac80211 layer=20
> design does have a better idea for this?

Is it even an issue to switch to ieee80211_tx_status_ext()? The context
here looks OK, although it might lead to (too?) deep call stacks.

I don't like the _irqsafe() versions anyway ...

johannes