From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.axiontech.ca (unknown [207.164.255.36]) by lists.ozlabs.org (Postfix) with ESMTP id D27B31A00B0 for ; Wed, 7 Jan 2015 04:38:33 +1100 (AEDT) From: Michael Tessier To: Alan Stern Subject: RE: PROBLEM: USB isochronous urb leak on EHCI driver Date: Tue, 6 Jan 2015 17:38:29 +0000 Message-ID: <66A26A9AA227D947AF088537F041526E2009E5@VSVR-EX10-MB1.pocatec.com> References: <66A26A9AA227D947AF088537F041526E2009B9@VSVR-EX10-MB1.pocatec.com> In-Reply-To: Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Cc: "linuxppc-dev@lists.ozlabs.org" , "linux-usb@vger.kernel.org" List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , > > > > That is interresting, however, I have an older kernel running an=20 > > > > OHCI driver which is able to handle 4 codecs. Same usb hardware=20 > > > > (codecs and hub), but older kernel on a different CPU, with much=20 > > > > less power. This makes me believe that there's a solution to make i= t work... > > >=20 > > > Of course there is: Install an OHCI host controller and use it to dri= ve your codecs. It should work fine. What do you mean by that? The host controller is embedded in the i.MX CPU..= . Changing the CPU is not really an option to me. Unless I am missing something? > > >=20 > > > The periodic scheduling algorithm for OHCI is very different from the= algorithm for EHCI. > >=20 > > According to your knowledge, how much time would you think it takes to= =20 > > change the EHCI driver with an OHCI one? > > I don't understand the question. > > > And can you tell if the OHCI driver > > will work on my hardware given that the Host controller of the i.MX512= =20 > > is a USB2.0 host controller? (OHCI was implemented for USB 1.x from=20 > > what I > > understand) > > The OHCI driver works with OHCI hardware and the EHCI driver works with E= HCI hardware. OHCI is USB-1.1 and EHCI is USB-2. They are not interchange= able. That was what I thought first... > > > I tried to do so several days ago with the built-in configurator (I am= =20 > > using "ltib"), but the configurator does not allow selecting the OHCI=20 > > driver; I tried manually but it turned into compiler errors... > > It looks like the configurator is smart; it won't let you select the wron= g driver for your hardware. > > Alan Stern