From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from alexmail (62-90-235-247.barak.net.il [62.90.235.247]) by ozlabs.org (Postfix) with ESMTP id C48F2689D9 for ; Wed, 8 Feb 2006 01:18:52 +1100 (EST) Message-ID: <43E8ACB3.6030401@compulab.co.il> Date: Tue, 07 Feb 2006 16:20:35 +0200 From: Mike Rapoport MIME-Version: 1.0 To: Laurent Pinchart Subject: Re: CPM2 USB driver & MPC8248 References: <200602031210.12603.laurent.pinchart@tbox.biz> <43E5BAE8.9000507@compulab.co.il> <200602071414.28551.laurent.pinchart@tbox.biz> In-Reply-To: <200602071414.28551.laurent.pinchart@tbox.biz> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Cc: linuxppc-embedded@ozlabs.org List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Laurent Pinchart wrote: >How is the driver development going ? You're not using the sourceforge CVS/SVN >repository, is there another one somewhere (maybe a git tree) ? Are you >actively working on performance issues, or is the development currently >stalled ? > > The driver development is stalled and I don't know when I'll be able to continue working on it. >What are the major performance issues ? > > One of the issues in this driver is redunduncy between qe end ep structures and as a consequence a lot of uneeded code that make cross updates. I didn't run profiling, so I can't tell better. >I noticed that the driver uses the MPC82xx packet level interface. >Why don't you use the transaction level interface ? > > The original driver I've started with used packet level. I thought on switching to transaction level, but I hadn't time for it because of other projects pressure. > > >>Another thing that may cause problems is how storage devices treat SOF >>packets, but I'm not USB expert enough to be sure about that. >> >> > >That might explain why some devices don't even respond to the first request. I >noticed that, on my EP8248 board, the controller only sends 990 SOF packets >per second (or rather 990 SOF interrupts are generated). I might have a time >base problem somewhere, as I computed the number of interrupts per second >with a simple > >cat /proc/driver/m8xxhci_privateh > sof.1 && sleep 300 && >cat /proc/driver/m8xxhci_privateh > sof.2 > > > I'm not sure such measurements are correct, since you sleep not exatly 300 seconds. I haven't measured how many SOF interrupts I get, but I think you maybe right. It may happen that during transmit or recieve the interrupts are off and SOF packets are not sent. >Do you have the same problem ? I'll see if I can get my hands on a USB >protocol analyzer. > > Good luck, I'll try to help but unfotunately I'm very much busy with other projects now. >Laurent Pinchart > > > > > -- Sincerely yours, Mike Rapoport