From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pigeon.gentoo.org ([69.77.167.62] helo=lists.gentoo.org) by finch.gentoo.org with esmtp (Exim 4.60) (envelope-from ) id 1Ldqb9-0000hH-4X for garchives@archives.gentoo.org; Sun, 01 Mar 2009 18:41:11 +0000 Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id F3AF0E01D8; Sun, 1 Mar 2009 18:41:08 +0000 (UTC) Received: from wa-out-1112.google.com (wa-out-1112.google.com [209.85.146.178]) by pigeon.gentoo.org (Postfix) with ESMTP id B278EE01D8 for ; Sun, 1 Mar 2009 18:41:08 +0000 (UTC) Received: by wa-out-1112.google.com with SMTP id j4so973205wah.2 for ; Sun, 01 Mar 2009 10:41:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:content-type :content-transfer-encoding; bh=XXzo18oSGtfFlptG5lClbadPJwMnW4F6k8wAjtg9n30=; b=qHhwboyQi2bRYlzuOtY0lk1IlDvOK+dvOvmotkelwoenCoYs5Nqm6PMZ1UQHGTpi7L Y/eMxu/QXOPYpVxWzVS1qTL17dLwCFuUQFRv0S8Kd73Y+7aKi0zmZa0MJNlQHExGS1hy 00KkfiOoN5LEZMwnWwoR8BtGi3dkX1eHzyS8w= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type:content-transfer-encoding; b=Ug+kqI+PXSOKEdCxDej3C4FVPRO6UDdOa4SRFzNiI/v6D6mHcbXIyw7Lm1aJdxJ2E6 02ervM/3nbHUG+a+Lsde3rbgH4Q4NeXqO4Qe2suKlkd4WfKwTcvwV6Axdl+nCui+Vs3z sEkCgvCgsJznVAedxuiSjAhl7/RP0oFT+uOlA= Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org MIME-Version: 1.0 Received: by 10.115.22.1 with SMTP id z1mr2242563wai.202.1235932868148; Sun, 01 Mar 2009 10:41:08 -0800 (PST) In-Reply-To: <5bdc1c8b0902281030g27c18dc3v9ecd20bc49c7b844@mail.gmail.com> References: <49bf44f10902261934l1d33ff17nd64fbfaff4d5b1a3@mail.gmail.com> <49bf44f10902270737s7cd41da0t734fdc00d5c67a73@mail.gmail.com> <49A80CEE.5000200@gmail.com> <49bf44f10902270900q2ec748f6p489fc1839bf32f7d@mail.gmail.com> <49A82351.8090009@gmail.com> <49bf44f10902271221k30134a9fg907bc477dfc3683@mail.gmail.com> <49bf44f10902280654y4dd8da38mfadbb63d43067bf9@mail.gmail.com> <5bdc1c8b0902281030g27c18dc3v9ecd20bc49c7b844@mail.gmail.com> Date: Sun, 1 Mar 2009 10:41:08 -0800 Message-ID: <49bf44f10903011041q2c54d91cu7361555ba6ac43af@mail.gmail.com> Subject: Re: [gentoo-user] Re: Which USB device on which controller? From: Grant To: gentoo-user@lists.gentoo.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-Archives-Salt: dd166b5a-0487-4918-a942-8efe3123a2c3 X-Archives-Hash: 7138dda3999a2d9e4b08a79c4cfe2d88 >>>>>> Sounds like it's a 1.1 device to me. >>>>> >>>>> Yep, that's what it sounds like to me too. >>>>> >>>>> Dale >>>> >>>> But that's OK isn't it? =A0I don't need 2.0 speeds between each webcam >>>> and the controller, I just need the increased overall bandwidth of a >>>> 2.0 controller so one of the 1.1 webcams doesn't use all of it. >>> >>> The 2.0 controller doesn't _have_ increased bandwith if it's >>> talking to 1.1 devices. =A0In that case, the 2.0 controller is >>> transferring data at the same speed as a 1.1 controller. >> >> I thought the total bandwidth available for a controller was different >> than the bandwidth at which it communicates with one device. =A0You're >> saying any 1.1 device that uses 12 mbit/s will 100% monopolize a 2.0 >> controller so no other devices can function? >> > > Yes. USB is not like 1394/Firewire. Firewire will increase and > decrease bandwidth as different devices take control of the bus. There > is negotiation between devices and the device that owns the bus > controls how the bus is used. > > With USB a 1.1 device on the bus causes the 2.0 controller to operate > at 1.1 speed so there is only 12Mb/S on that bus once you plug the 1.1 > web cam in. > >> Taking a different approach, since I have 2 USB controllers (EHCIx1, >> OHCIx1) why can't I operate one webcam on one controller and one >> webcam on the other controller so they can both function? >> > > If the hardware is working correctly, if the drivers are independent, > and IF IF IF the two physical ports you chose are actually going to > completely different controllers then you can. I do this. This sort of > thing becomes an issue with USB when you make a mistake an plug an old > USB mouse or keyboard into the wrong physical port and bring your 2.0 > bus speed down to 1.1 bandwidth. > > Over and out, > Mark Thanks everyone. Sounds like I need another USB controller or 2.0 webcams. - Grant >> - Grant >> >>>> I get the feeling I have a misconception somewhere along the >>>> line here. Could someone straighten me out? >>> >>> A Corvette going 3MPH will get to the finish line at exactly >>> the same time as a 4-year-old kid on a tricycle going 3MPH. =A0It >>> doesn't matter what the controller is capable of -- it matters >>> what speed it's actually talking. >>> >>> -- >>> Grant