[Dextrose] Modifying 353 (xo-1) to apply the dev.laptop.org/ticket/10195 fix {XO Wifi Issues}

[Samuel Greenfeld]

Pardon me if I missed the clarification, but if one XO unit is 
consistently bad while another physical XO unit always works regardless 
of their locations, this would suggest a hardware issue.

Your truncated "scan-wifi" output suggests that the bad XOs only were 
working on Channel 1.  I'd be curious to see if the bad XOs could talk 
to good XOs on all 3 mesh channels (1, 6 & 11) even if placed a decent 
distance apart.  These appear as separate mesh icons you can connect to 
manually in Sugar.


Although this may not apply to your case, from observation I have 
noticed that "scan-wifi" provides very few (5-8, varying between runs) 
results on an XO in an urban city, while "iwlist eth0 scan" typically 
finds 25-40 Access Points per scan.  Run repetitively, the AP I want to 
connect to often appears in a single iwlist scan, but often does not 
appear as well.

Using an 802.11 monitoring tool on a non-XO finds 100 APs are nearby in 
~15 seconds with that number going over 200 within a few minutes.  While 
your environment may not be as extreme, if iwlist shows you have a lot 
of APs in your area or you know there are other 2.4 GHz devices in use, 
this may be part of the problem.

---
SJG


On 11/29/2010 9:21 PM, Mikus Grinbergs wrote:
> Quozl wrote:
>>> A symptom that I frequently observe is that 'iwlist eth0 scan'
>>> (as root) does not show the radio signals that other XO_1s do show.
>>     Use scan-wifi in OpenFirmware in order to exclude the operating
>>     system configuration from the problem.
> Thank you, thank you, thank you.  This gives me a 'starting point'.
>
> To 'scan-wifi', the "bad" XO-1s return lines like this:
>
>    RSSI:  0 SSID:              Channel 1
>     ...
>    RSSI:  0 SSID:              Channel 1
>    RSSI: 41 SSID:              Channel 1
>
> To 'scan-wifi', the "good" XO-1s return lines like this:
>
>    RSSI:  0 SSID:              Channel 1
>     ...<more such lines than the "bad" XO-1s>
>    RSSI:  0 SSID:              Channel 1
>    RSSI: 85 SSID:  2WIRE241    Channel 11
>
>
> Note that both the "bad" XO1-s and the "good" XO-1s __will__ connect via
> the (non-adhoc) mesh interface -- to me that says the silicon is working
> -- though I do not know if the AP radio signal in the "bad" XO-1s is too
> attenuated (bad antenna connection?) to be detected.
>
>
> Thanks again,  mikus
>
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