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Subject: Re: [PATCH 1/9] wifi: mac80211: allow enabling chanctx until hw
 registration
From:   Johannes Berg <johannes@sipsolutions.net>
To:     sean.wang@mediatek.com, nbd@nbd.name, lorenzo.bianconi@redhat.com
Cc:     Soul.Huang@mediatek.com, YN.Chen@mediatek.com,
        Leon.Yen@mediatek.com, Eric-SY.Chang@mediatek.com,
        Deren.Wu@mediatek.com, km.lin@mediatek.com,
        jenhao.yang@mediatek.com, robin.chiu@mediatek.com,
        Eddie.Chen@mediatek.com, ch.yeh@mediatek.com,
        posh.sun@mediatek.com, ted.huang@mediatek.com,
        Stella.Chang@mediatek.com, Tom.Chou@mediatek.com,
        steve.lee@mediatek.com, jsiuda@google.com, frankgor@google.com,
        kuabhs@google.com, druth@google.com, abhishekpandit@google.com,
        shawnku@google.com, linux-wireless@vger.kernel.org,
        linux-mediatek@lists.infradead.org
Date:   Tue, 16 Aug 2022 10:03:29 +0200
In-Reply-To: <473fc7b169f288b7815a7736cf33ac0ec1599a09.1660606893.git.objelf@gmail.com>
References: <cover.1660606893.git.objelf@gmail.com>
         <473fc7b169f288b7815a7736cf33ac0ec1599a09.1660606893.git.objelf@gmail.com>
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On Tue, 2022-08-16 at 08:03 +0800, sean.wang@mediatek.com wrote:
> From: Sean Wang <sean.wang@mediatek.com>
>=20
> MT7921 device can be supported with the channel context depending on
> the newer firmware so that we need a way to enable the chanctx related
> methods until hw is being registered.
>=20
> Signed-off-by: Sean Wang <sean.wang@mediatek.com>
> ---
>  net/mac80211/main.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
>=20
> diff --git a/net/mac80211/main.c b/net/mac80211/main.c
> index 5b1c47ed0cc0..98d05ed1a081 100644
> --- a/net/mac80211/main.c
> +++ b/net/mac80211/main.c
> @@ -1011,6 +1011,14 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
>  		return -EINVAL;
>  #endif
> =20
> +	/* check all or no channel context operations exist */
> +	i =3D !!local->ops->add_chanctx + !!local->ops->remove_chanctx +
> +	    !!local->ops->change_chanctx + !!local->ops->assign_vif_chanctx +
> +	    !!local->ops->unassign_vif_chanctx;
> +	if (WARN_ON(i !=3D 0 && i !=3D 5))
> +		return -EINVAL;
> +	local->use_chanctx =3D i =3D=3D 5;
> +

Not sure I understand this - this just *adds* code, based on the
description I would've expected you to *move* code?

In any case, I'm not sure I see how this makes sense - ops is supposed
to be const, and you're supposed to pass it to alloc_hw already, so how
would it change?!

Also, conceptually, I'm not sure why it's needed to alloc_hw before
loading firmware, we also have a lot of things depend on the firmware
capabilities in iwlwifi/mvm, and so we alloc/register HW after loading
firmware.

johannes