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Date:   Wed, 15 Nov 2023 17:00:23 +0100
From:   Johan Hovold <johan@kernel.org>
To:     Johannes Berg <johannes@sipsolutions.net>
Cc:     linux-wireless@vger.kernel.org,
        Johannes Berg <johannes.berg@intel.com>
Subject: Re: [PATCH] wifi: cfg80211: hold wiphy mutex for send_interface
Message-ID: <ZVTrF7xPsf-JseJ5@hovoldconsulting.com>
References: <20231115130615.b1ccadaf9e13.Ic207e2f99f806e9120278f92fdebc2822842c301@changeid>
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On Wed, Nov 15, 2023 at 01:06:16PM +0100, Johannes Berg wrote:
> From: Johannes Berg <johannes.berg@intel.com>
> 
> Given all the locking rework in mac80211, we pretty much
> need to get into the driver with the wiphy mutex held in
> all callbacks. This is already mostly the case, but as
> Johan reported, in the get_txpower it may not be true.
> 
> Lock the wiphy mutex around nl80211_send_iface(), then
> is also around callers of nl80211_notify_iface(). This
> is easy to do, fixes the problem, and aligns the locking
> between various calls to it in different parts of the
> code of cfg80211.
> 
> Fixes: 0e8185ce1dde ("wifi: mac80211: check wiphy mutex in ops")
> Reported-by: Johan Hovold <johan@kernel.org>
> Closes: https://lore.kernel.org/r/ZVOXX6qg4vXEx8dX@hovoldconsulting.com
> Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Thanks for the quick fix. With this I no longer see any lockdep splat on
boot with the X13s:

Tested-by: Johan Hovold <johan+linaro@kernel.org>

Johan