To: linux-wireless@vger.kernel.org
From: Mike Turner <miketurner.forum@gmail.com>
Subject: rtl8192cu beacon fix unreliable
Date: Fri, 13 Feb 2015 10:48:47 +0000 (UTC)
Message-ID: <loom.20150213T114021-973@post.gmane.org> (sfid-20150213_115011_339531_7BDFCD7D)
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Sender: linux-wireless-owner@vger.kernel.org

When using hostapd and an rtl8192cu Wireless USB adaptor the beacon 
doesn't start sometimes. This was tested with the 

kernel/git/davem/net-next.git repository

and

3423eb92315865d76cb8d488513bfef6ab9251d0

This behaviour is apparently random. If the beacon starts OK then it 
continues. If a beacon isn't generated then it never starts. Repeating 
cycles of hostapd stop/start may or may not generate a beacon. There are 
no specific error messages displayed either on console or in syslog. I 
have repeated hostapd stop/start a number of consecutive times and 
received a beacon each time, however I have also done this a number of 
times and never generated a beacon.

We have succesfully used the pvaret-rtl8192cu driver which is based on the 
vendor driver and used that in conjunction with the modified hostapd code 
that requires use of the rtl871xdrv driver interface and as far as we have 
seen it always generates a beacon. 

Platform is a custom designed Atmel-ARM CPU (AT91SAM9G25) with a D-Link 
DWA-121.