From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail.kapsi.fi ([217.30.184.167]:50801 "EHLO mail.kapsi.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751519AbZIKOiN (ORCPT ); Fri, 11 Sep 2009 10:38:13 -0400 Message-ID: <4AAA60D0.50706@iki.fi> Date: Fri, 11 Sep 2009 17:38:08 +0300 From: Antti Palosaari MIME-Version: 1.0 To: "Aleksandr V. Piskunov" CC: Markus Rechberger , Devin Heitmueller , Clinton Meyer , Linux Media Subject: Re: LinuxTV firmware blocks all wireless connections / traffic References: <829197380909091459x5367e95dnbd15f23e8377cf33@mail.gmail.com> <20090910091400.GA15105@moon> <20090910124549.GA18426@moon> <20090910124807.GB18426@moon> <4AA8FB2F.2040504@iki.fi> <20090910134139.GA20149@moon> <4AA9038B.8090404@iki.fi> <4AA911B6.2040301@iki.fi> <20090910171631.GA4423@moon> <20090910193916.GA4923@moon> In-Reply-To: <20090910193916.GA4923@moon> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: On 09/10/2009 10:39 PM, Aleksandr V. Piskunov wrote: > On Thu, Sep 10, 2009 at 08:16:31PM +0300, Aleksandr V. Piskunov wrote: >> On Thu, Sep 10, 2009 at 05:48:22PM +0300, Antti Palosaari wrote: >>> Here it is, USB2.0 URB is now about 16k both af9015 and ce6230 devices. >>> Now powertop shows only about 220 wakeups on my computer for the both >>> sticks. >>> Please test and tell what powertop says: >>> http://linuxtv.org/hg/~anttip/urb_size/ >>> >>> I wonder if we can decide what URB size DVB USB drivers should follow >>> and even add new module param for overriding driver default. >> >> Thanks, Antti! >> >> Tested your branch on affected system. >> >> Load definitely went down, from ~7000 wakeups to ~250 for each tuner >> according to powertop. >> Both tuners still working ok if not used simultaneously or if used the >> same time on different USB controllers. >> >> Bad news are that original problem still persists: putting both tuners >> on same USB controller and zapping simultaneously corrupts stream. >> Interesting observation: no matter in what sequence tuners are connected >> (i.e. become adapter0 or adapter1), af9015 stream always gets heavily >> distorted, visually mplayer picture becomes like 80% corrupted with >> random color blocks and pixels, sound becomes a mess. At the same time >> ce6230 gets slight corruption, a few discolored blocks at the time and >> sound hickups. >> >> Anyway, will try to do a few more tests: >> 1) Two usb flash drives on same controller calculating md5sum of >> big .iso file, to check if it is/isn't dvb-usb problem. >> 2) Will see if same issue persists on another PC with same motherboard >> (slightly different revision) to rule out hardware issues. If I manage >> to wire antenna there, that is... > > Ok, two USB flash drives on same controller, no problem when bulk reading > from both at the same time, no speed drops, no corruption. > > Now if I plug ce6230 tuner, zap to channel and then start reading from > flash drive: > * slightly corrupted TS stream > * flash drive read getting starved on bandwidth, speed drops from 10 MB/s > to ~7 MB/s > > If I plug af9015 tuner, zap and read from flash > * heavy corruption of TS stream > * flash drive read speed drops from 10 MB/s to 2(!) MB/s > > Now I don't really know the USB protocol under-the-hood details, all the > different types of bandwidth, reservation and so on. But shouldn't one > 480 Mbit/sec controller handle rather large number of digital tuners, each > pushing 20-25 Mbit/sec max, even considering all the overhead? I have no any problems here, ce6230 and af9015 with dual tuners (3x DVB-T 22Mbit/sec TS streams) running same time on same bus. One possibility is that there is RF-noise looping from device to device disturbing USB transfer or RF-signal. I have seen such situation when I connect multiple DVB-C devices to same antenna cable using cheap splitter. Anyhow, I increased URB sizes to 65k. Now ce6230 gives 70 wakeups and af9015 120 wakeups - due to remote polling. You can test if you wish, but results are most likely same as earlier. I cannot do much more. http://linuxtv.org/hg/~anttip/urb_size/ Antti -- http://palosaari.fi/