From: Ben Greear Date: Mon, 06 Dec 2010 12:22:26 -0800 Subject: [ath9k-devel] Script to crash ath9k with DMA errors. In-Reply-To: References: <4CF44543.9070605@candelatech.com> <20101130004424.GC1901@tux> <4CF6D8C8.2000308@candelatech.com> <4CF8A6DE.4020804@candelatech.com> <4CFAFBE1.3080505@openwrt.org> <4CFB20BA.5090300@candelatech.com> <20101206193600.GC21442@tux> <4CFD3DE3.4000207@candelatech.com> Message-ID: <4CFD4602.1030304@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 On 12/06/2010 12:11 PM, Bj?rn Smedman wrote: > On Mon, Dec 6, 2010 at 8:47 PM, Ben Greear wrote: >> With 16 properly configured non-encrypted stations, running with >> wpa-supplicant >> with netlink driver& sharing scan results, the interfaces quickly >> associate. >> >> However, I do continue to see DMA warnings such as these (I had picked up my >> portable phone, and it knocked all the interfaces offline ..here >> they are coming back up after I hung up the phone). > > Is there some theory as to why using multiple interfaces cause so many > problems with DMA? Seems pretty directly related to channel changes and/or resets, and exacerbated by other interfaces sending data while another is scanning, for instance. Other issues we've found in the past have been various races that you wouldn't normally see with a single VIF. Thanks, Ben > > /Bj?rn -- Ben Greear Candela Technologies Inc http://www.candelatech.com