[Server-devel] [XSCE] Large groups of XO-1 do not work with access points

[Jon Nettleton]

On Fri, Feb 7, 2014 at 6:08 AM, James Cameron <quozl at laptop.org> wrote:
> On Thu, Feb 06, 2014 at 05:09:47PM -0500, Tim Moody wrote:
>> James wrote:
>> >The XO-1 will consume more of the available bandwidth than an XO-1.5
>> >or later, because each XO-1 continually transmits mesh beacons even if
>> >mesh is not in use.  Each XO-1 also responds to every scan (probe
>> >request) by every other laptop.
>>
>> I'm not sure what you mean by 'even if mesh is not in use'.  Do you
>> mean even if it has been explicitly turned off with echo 0 >
>> /sys/class/net/eth0/lbs_mesh?
>
> No.  What I mean by "even if mesh is not in use", is "even if a mesh
> network icon has not been selected by the user, and has not been
> automatically selected by Sugar, and the laptop is associated with an
> access point".
>
> Disabling the mesh using /sys/class/net/eth0/lbs_mesh does prevent the
> 409.6ms beacons.  This is easily demonstrated using monitor mode and
> tcpdump.
>

For the people seeing these problems and trying to debug could you
please run this command at startup to get some additional debug output
from the libertas driver?

echo 0x6180 > /sys/module/libertas/parameters/libertas_debug

For more debug options please reference,
http://wiki.laptop.org/go/Libertas_Debug

To both disable mesh and setup debug on boot do something like this.

echo "options libertas libertas_debug=0x6180 libertas_disablemesh=1" >
/etc/modprobe.d/libertas.conf

When testing for AP visibility please use iwlist scan rather than the
network view within Sugar.  NM compatibility bugs can skew the
perceived results.  It is much better to capture the data to analyse
at a closer level to the kernel driver.  This could very well be a NM
bug rather than an AP wifi driver bug.

After you have have tested with the above options set, please report
back with dmesg and `iwlist scan` output from both a successfully
connected client, and a failed client.  Also if you can export the
wifi settings for a router that exhibits the problem vs one that does
no that would be useful as well.

I understand some/all of these steps may have been done already.  If
they have could you pass on the results, or point me to a location I
can look at them?

Thanks
-Jon