Received-SPF: pass (google.com: domain of linux-wireless-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Message-ID: <f3cf96426f9532904c9f256d963e7915aa399a90.camel@sipsolutions.net>
Subject: Re: [PATCH 2/3] nl80211: add control port tx status method
From:   Johannes Berg <johannes@sipsolutions.net>
To:     Markus Theil <markus.theil@tu-ilmenau.de>
Cc:     linux-wireless@vger.kernel.org
Date:   Tue, 26 May 2020 15:37:51 +0200
In-Reply-To: <20200508144202.7678-3-markus.theil@tu-ilmenau.de> (sfid-20200508_164230_875169_22AD02AA)
References: <20200508144202.7678-1-markus.theil@tu-ilmenau.de>
         <20200508144202.7678-3-markus.theil@tu-ilmenau.de>
         (sfid-20200508_164230_875169_22AD02AA)
Content-Type: text/plain; charset="UTF-8"
User-Agent: Evolution 3.36.2 (3.36.2-1.fc32) 
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Sender: linux-wireless-owner@vger.kernel.org
Precedence: bulk


>  	struct idr ack_status_frames;
>  	spinlock_t ack_status_lock;
>  
> +	u64 ctrl_port_cookie_counter;

We have a u64 for other things (remain-on-channel), perhaps should just
share? It's not going to overflow even if shared ...

>  	/* disable bottom halves when entering the Tx path */
>  	local_bh_disable();
> -	__ieee80211_subif_start_xmit(skb, dev, flags, 0);
> +	__ieee80211_subif_start_xmit(skb, dev, flags, 0, NULL);

This is a little awkward, any way to avoid that? Probably not ...

> +static u16 ieee80211_store_ack_skb(struct ieee80211_local *local,
>  				   struct sk_buff *skb,
> -				   u32 *info_flags)
> +				   u32 *info_flags,
> +				   bool use_socket,
> +				   u64 *cookie)
>  {
> -	struct sk_buff *ack_skb = skb_clone_sk(skb);
> +	struct sk_buff *ack_skb;
>  	u16 info_id = 0;
>  
> +	if (use_socket)

You can check skb->sk and not need the additional parameter.

>  	if (unlikely(!multicast && skb->sk &&
>  		     skb_shinfo(skb)->tx_flags & SKBTX_WIFI_STATUS))
> -		info_id = ieee80211_store_ack_skb(local, skb, &info_flags);
> +		info_id = ieee80211_store_ack_skb(local, skb, &info_flags,
> +						  true, NULL);
> +
> +	if (unlikely(!multicast && ctrl_flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
> +		info_id = ieee80211_store_ack_skb(local, skb, &info_flags,
> +						  false, cookie);

I think this should be rolled into one condition, since you no longer
need the true/false if you check skb->sk. And 'cookie' is already NULL
in those other cases so you can pass it unconditionally.

> @@ -2765,8 +2795,9 @@ static struct sk_buff *ieee80211_build_hdr(struct ieee80211_sub_if_data *sdata,
>  	if (skb_shared(skb)) {
>  		struct sk_buff *tmp_skb = skb;
>  
> -		/* can't happen -- skb is a clone if info_id != 0 */
> -		WARN_ON(info_id);
> +		if (!(ctrl_flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
> +			/* can't happen -- skb is a clone if info_id != 0 */
> +			WARN_ON(info_id);

This I don't understand, but if it really is needed then you should
adjust the comment and roll it into a single WARN_ON().

Also, please put all the remaining mac80211 changes into one patch - I
already put all the other changes in.

johannes