Fwd: XO (88W8388) roaming issues

Franco Miceli fmiceli at plan.ceibal.edu.uy
Mon Aug 19 10:05:59 PDT 2013


Dan,

We have been running some tests on different machines, of different
model, in order to verify the patch's thresholds.

Roaming performance is now more stable. I am attaching the test
results as a PDF.

I have noticed that this change did not make it into wpa_supplicant
2.0. Is there a reason for that? Can the report be considered as a
validation so the change can be included in future versions of
wpa_supplicant?

Thanks for all the help.

BR,


2013/3/27 Franco Miceli <fmiceli at plan.ceibal.edu.uy>
>
> Great. Will apply the patch then.
>
> Thanks.
>
> BR,
>
>
> 2013/3/27 Dan Williams <dcbw at redhat.com>
>>
>> On Wed, 2013-03-27 at 12:21 -0300, Franco Miceli wrote:
>> > Great news then.
>> >
>> > We will be deploying F18 builds which include wpa_supplicant 1.0.
>>
>> I think even with 1.0 and F18 you'll want the patch I attached.
>> Actually, it's likely I'll just add the patch to the Fedora builds
>> anyway, since the upstream defaults here are pretty clearly wrong for
>> most drivers.
>>
>> Dan
>>
>> > At this instance we will test the roaming feature and see if it improves.
>> >
>> > Thanks for the info. Will report back the results.
>> >
>> > BR,
>> >
>> >
>> >
>> >
>> > 2013/3/27 Dan Williams <dcbw at redhat.com>
>> >
>> > > On Wed, 2013-03-27 at 09:37 -0300, Franco Miceli wrote:
>> > > > That could be the case, since we are using wpa
>> > > > _supplicant-0.6.8-10.fc14.i686.
>> > > >
>> > > > But from another mal exchange with you I got the impression that
>> > > wpa_supplicant
>> > > > did not take part in roaming on the XO laptop (Libertas-Thick Firmware).
>> > >
>> > > I looked again at the libertas kernel driver and I believe that the
>> > > supplicant does actually control the roaming with this firmware.  Some
>> > > older hardware (orinioco, airo) does do all the roaming in firmware, but
>> > > the libertas lets the supplicant control that.  Most of the rest of it
>> > > is thick-firmware style though :)
>> > >
>> > > > Can I expect changes from using wpa_supplicant with version higher than
>> > > 0.7
>> > > > on the XO laptop?
>> > >
>> > > You could try to apply the following patch to the 0.7 supplicant, or you
>> > > could try 1.0 or later, but even with later versions, you may need a
>> > > patch like the following.
>> > >
>> > > Dan
>> > >
>> > > ---
>> > > diff -up wpa_supplicant-0.7.3/wpa_supplicant/events.c.foo
>> > > wpa_supplicant-0.7.3/wpa_supplicant/events.c
>> > > --- wpa_supplicant-0.7.3/wpa_supplicant/events.c.foo    2012-06-12
>> > > 12:03:36.172962193 -0500
>> > > +++ wpa_supplicant-0.7.3/wpa_supplicant/events.c        2012-06-12
>> > > 12:03:51.388771973 -0500
>> > > @@ -871,16 +871,14 @@ static int wpa_supplicant_need_to_roam(s
>> > >
>> > >         min_diff = 2;
>> > >         if (current_bss->level < 0) {
>> > > -               if (current_bss->level < -85)
>> > > -                       min_diff = 1;
>> > > -               else if (current_bss->level < -80)
>> > > -                       min_diff = 2;
>> > > -               else if (current_bss->level < -75)
>> > > -                       min_diff = 3;
>> > > -               else if (current_bss->level < -70)
>> > > +               if (current_bss->level < -75)
>> > >                         min_diff = 4;
>> > > +               else if (current_bss->level < -70)
>> > > +                       min_diff = 6;
>> > > +               else if (current_bss->level < -65)
>> > > +                       min_diff = 8;
>> > >                 else
>> > > -                       min_diff = 5;
>> > > +                       min_diff = 15;
>> > >         }
>> > >         if (abs(current_bss->level - selected->level) < min_diff) {
>> > >                 wpa_printf(MSG_DEBUG, "Skip roam - too small difference in
>> > > "
>> > >
>> > >
>> > >
>> >
>> >
>>
>>
>
>
>
> --
> Ing. Franco Miceli
> CITS - Plan Ceibal - Investigación & Desarrollo
> Av. Italia 6201 - Montevideo, Uruguay
> CP: 11500
> Tel: (598 2) 601 5773 int.: 2227




-- 
Ing. Franco Miceli
Coordinador de Proyectos de I+D - Plan Ceibal

Av. Italia 6201 - Montevideo, Uruguay
CP: 11500
Tel: (598 2) 601 5773 int.: 2232



-- 
Ing. Franco Miceli
Coordinador de Proyectos de I+D - Plan Ceibal
Av. Italia 6201 - Montevideo, Uruguay
CP: 11500
Tel: (598 2) 601 5773 int.: 2232
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