Return-path: Received: from mail-bw0-f46.google.com ([209.85.214.46]:37808 "EHLO mail-bw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754465Ab1KQTUX (ORCPT ); Thu, 17 Nov 2011 14:20:23 -0500 Received: by bke11 with SMTP id 11so2434210bke.19 for ; Thu, 17 Nov 2011 11:20:21 -0800 (PST) From: Helmut Schaa To: Andreas Hartmann Cc: users@rt2x00.serialmonkey.com, "linux-wireless@vger.kernel.org" Subject: Re: Re: Try to narrow down the problem with rt2800usb and rt3572 based USB WLAN devices Date: Thu, 17 Nov 2011 20:20:13 +0100 Message-ID: <4540730.yCbFJVVBHk@helmutmobil.site> (sfid-20111117_202026_707040_74C56E62) In-Reply-To: <4EC15D4F.1010207@dualc.maya.org> References: <4EBEA616.2020002@01019freenet.de> <4EC15D4F.1010207@dualc.maya.org> MIME-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Sender: linux-wireless-owner@vger.kernel.org List-ID: Am Montag, 14. November 2011, 19:26:23 schrieb Andreas Hartmann: > Hello Helmut, > > Helmut Schaa schrieb: > > On Sat, Nov 12, 2011 at 6:00 PM, Andreas Hartmann > > wrote: > >> Could anybody please try to explain this behavior, or even better, fix > >> it (it looks really broken to me)? > > > > AFAIK it is possible to aggregate multiple frames into one URB > > for rt2800 USB devices. However, rt2800usb doesn't make use > > of this yet while the legacy driver does. > > Hmm, could this be the reason, why the device gets extremely hot during > operation, especially when used in monitor mode (with airmon-ng)? Interesting, maybe this is related, yes. Not sure though. > Oh, I just remember, that during my "seven more packets" sniffing, the > monitor mode of this device stalled after a few minutes. Probably the > same reason why it doesn't work very well (respectively stalls > completely) during normal mode. > > One more thing: > At the moment, the tcp data transfer stalls, no more usb packets can be > seen ... . > > > However, I don't think that > > this is the cause for the poor performance you see ... > > Is it normal, that the device gets fired up with submits without waiting > for any answers? The usb handling with the legacy driver is absolutely > regular (submit / complete / submit / complete), the handling with the > rt2800usb driver just looks totally messy to me (the urb ids of the > submit / completes don't fit any more, even the "complete" comes before > the "submit" (see package 83056 and 83062) ?!). Unfortunately I don't know the rt2800 USB code very well but the tx status handling was changed some time ago to read the TX_STA_FIFO register asynchronously ... Helmut > > Thanks for your explanation, > Andreas