Disabling SMPS (Spatial multiplexing power save) when 802.11n is not used

Jouni Malinen j at w1.fi
Fri Mar 18 10:54:22 PDT 2016

On Fri, Mar 18, 2016 at 05:13:28PM +0100, Jose Blanquicet wrote:
> I am using the Marvell driver sd8887 without any particular wpa_supplicant
> configuration.
> I also agree that your fix is more appropriated. I tried it and it
> works also with
> Marvell driver.


> I think that mac80211_hwsim does not take into account
> smps_mode parameter when ht is disabled, which is right. But instead,
> Marvell driver and maybe others report error -22 (Invalid argument) if they
> receive smps_mode and it is set to a value different than OFF; of course
> when disable_ht=1.

Well, wpa_supplicant should not really be adding this attribute in such
a case and I'll push in the fix for that.

> On the other hand, I would like to make a question (I do not know if it should
> be done in another discussion, if so let me know and I will create a new one).
> The fact is that I have been able to use a, g, n and ac 802.11 modes but not
> b. I get 802.11n or ac using disable_ht and disable_vht parameters.
> Additionally, if I disable both parameters I get 802.11g mode and if I also set
> frequency to a channel in 5GHz I get 802.11a mode. But I do not know how
> to properly set the network parameters to enable 802.11b mode. How can I
> do this?

I don't think wpa_supplicant supports this. You can use hostapd to be
configure AP with hw_mode=b if you need to configure this special (i.e.,
obsolete..) case.

Jouni Malinen                                            PGP id EFC895FA

More information about the Hostap mailing list