Scan trigger failed: ret=-22 (Invalid argument)

Andrew Shadura andrew at
Wed Dec 27 07:19:57 PST 2017

On 23/12/17 08:14, YOSHINO Yoshihito wrote:
> Hello,
> I use wpa_supplicant in Debian GNU/Linux unstable.
> I have stuck in a problem with wpa_supplicant 2.6. After upgrading
> wpa_supplicant from 2.4 to 2.6 my laptop (MacBook Air with wifi chip
> "Broadcom Limited BCM4360 802.11ac Wireless Network Adapter
> [14e4:43a0] (rev 03)",
> with broadcom-sta's wl kernel module) fails to start scanning AP repeatedly
> with the following (-ddd) messages:


> This has been reported more than a year ago with wpa_supplicant version 2.5 to
> Debian's bug report system: (wpasupplicant:
> Unable to connect WLAN (wlan0: CTRL-EVENT-SCAN-FAILED ret=-22)).
> I have bisected commits between 2.4 and 2.6 and found the commit around 2.5-dev
> is the cause of the problem.
> It looks like the current wl kernel module does not accept a Probe Request
> frame with at least some part of the Extended Capabilities element.
> wpas_ext_capab_byte function in wpa_supplicant/wpa_supplicant.c unconditionally
> sets WNM-related values. Disabling the code like this


> Likewise a CONFIG_MBO block (several lines below the patch) would also need to
> be disabled, which I have not tested yet because Debian's .config does not set
> this option.
> While one of my collegues uses Lenovo Thinkpad laptop, with Intel's iwlwifi
> kernel module, which works with normal wpa_supplicant 2.6 without any problems.
> So it should switch depending on the kernel module used.
> I think one way to fix it would be to add some configuration variable for each
> network (via ctrl_iface/dbus and/or in wpa_supplicant.conf(5)) to decide
> whether it should emit WNM-related values or not and set the variable by hand
> or an external program like NetworkManager depending on the kernel module the
> network interface uses.
> Any ideas?

I, too, would like to have this issue resolved. Jouni, what would you
recommend as a temporary workaround?


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