[PATCH] don't continually reschedule specific scans

[Pavel Polischouk]

Dan Williams wrote:
> In situations where the driver does background scanning and sends a
> steady stream of scan results, wpa_supplicant would continually
> reschedule the scan.  This resulted in specific SSID scans never
> happening for a hidden AP, and the supplicant never connecting to the AP
> because it never got found.  Instead, if there's an already scheduled
> scan, and a request comes in to reschedule it, and there are enabled
> scan_ssid=1 network blocks, let the scan happen anyway so the hidden
> SSID has a chance to be found.
>   
Tested the patch as a possible way to fix "failure scenario 1" of this 
bug: https://bugzilla.redhat.com/show_bug.cgi?id=449215
The situation does improve - it is more often able to break the scanning 
deadlock, associate and proceed to authentication stage.

However, it doesn't work every time. Sometimes the scanning still times 
out. I do see the following lines in the log (generated with single -d):

---------------------------------
No suitable AP found.
Not rescheduling scan to ensure that specific SSID scans occur
Starting AP scan (specific SSID)
...
------------------------------------

However, subsequent arriving lists of available APs still list my AP as 
<hidden>. Is it possible the driver somehow ignores the scan request for 
a specific AP? Or supplicant somehow loses the correct scan lists?  The 
driver is ipw2200.

Also, I sometimes see in the log file that wpa_supplicant attempts to 
associate with AP 00:00:00:00:00:00, thinking it matches my ESSID.

Pavel