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Subject: Re: [PATCH v6] mac80211: Remove control.sta from struct
 ieee80211_tx_info and restructure tx-path
From: Johannes Berg <johannes@sipsolutions.net>
To: Thomas Huehn <thomas@net.t-labs.tu-berlin.de>
Cc: linux-wireless <linux-wireless@vger.kernel.org>,
	coelho <coelho@ti.com>
Date: Thu, 26 Jul 2012 18:46:05 +0200
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On Thu, 2012-07-26 at 18:31 +0200, Thomas Huehn wrote:

> This is the call path
> 
> in main.c ... INIT_WORK(&wl->tx_work, wl1271_tx_work);
>  jumps to tx.c...wl1271_tx_work(struct work_struct *work)
>   calls wl1271_tx_work(struct work_struct *work)
>    calls wlcore_tx_work_locked(struct wl1271 *wl)
>     calls wl1271_skb_queue_head()
>      calls wl12xx_tx_get_hlid()
>       calls wl12xx_tx_get_hlid_ap() .... where sta is needed.
> 
> But I could not find any point in the call path where I could grab the
> sta pointer and pass it through. I will move the rcu into
> wl12xx_tx_get_hlid_ap(), but I do not see any cheaper way here as using rcu.

I don't know this driver, maybe it could determine the hlid before and
store that.

johannes