From: Ben Greear Date: Mon, 20 Sep 2010 22:25:14 -0700 Subject: [ath9k-devel] ath9k, multiple stations, and AMPDUs Message-ID: <4C9841BA.4080700@candelatech.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ath9k-devel@lists.ath9k.org I think I have narrowed down some problems I see when I create two STA interfaces on the same radio and associate with the same AP. I'm using wireless-testing plus some patches to the rx logic I posted earlier. It appears that the ath9k NIC does not transport AMPDUs properly, and after a few seconds, it's backlog is exhausted and the queues are stopped in ath_tx_start. debugfs seems to agree: [root at atom ~]# cat /debug/ath9k/phy0/xmit BE BK VI VO MPDUs Queued: 2 0 0 85 MPDUs Completed: 2 0 0 85 Aggregates: 0 0 0 0 AMPDUs Queued: 144 0 0 0 AMPDUs Completed: 20 0 0 0 AMPDUs Retried: 18 0 0 0 AMPDUs XRetried: 0 0 0 0 FIFO Underrun: 0 0 0 0 TXOP Exceeded: 0 0 0 0 TXTIMER Expiry: 0 0 0 0 DESC CFG Error: 0 0 0 0 DATA Underrun: 0 0 0 0 DELIM Underrun: 0 0 0 0 [root at atom ~]# I can still receive packets on the interface, but nothing is transmitted. I tested against an a/b/g AP (instead of N), and it ran clean for many minutes. Any ideas how to debug this further? Thanks, Ben -- Ben Greear Candela Technologies Inc http://www.candelatech.com