Return-Path: Date: Mon, 1 Jan 2007 20:51:15 +0800 To: bluez-devel Message-ID: <20070101125115.GA4041@163.com> MIME-Version: 1.0 From: amateur Subject: [Bluez-devel] Data Transmission Error with OHCI Host Controller Reply-To: amateur , BlueZ development List-Id: BlueZ development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Sender: bluez-devel-bounces@lists.sourceforge.net Errors-To: bluez-devel-bounces@lists.sourceforge.net Hi Guys, I have a problem with bluez on a arm platform. Here is the detail: On the arm embedded platform, I invoke this command l2ping -s 667 BDADDR to test the bluetooth L2CAP connection, where BDADDR is the bluetooth address of my Linux/Bluez laptop. At the same time, I use hcidump -x -R on my laptop to monitor the bluetooth traffic. The problem is that the data I sent from the embedded arm platform got corrupted on receptioin. After a careful check, I found that the error has the following pattern: Some bytes of the ACL data packet, which corresponding to the L2CAP Echo Request Command, will have some 4 bytes of its content changed from valid data to 4 bytes of zero on occasion. And this change-to-zero error may occur several times in a ACL Packet sometimes. The distance between consecutive errors is always a multiple of 64-bytes which is the maxPacketSize of the USB pipe of the bluetooth dongle. The offset of the error position in the ACL Packet is always 64*i+4-64*i+7(4 bytes), where 'i' is an integer. I am really confused. I have checked the skb and urb associated with the ACL Packet. And they both looks fine(content correct). So where could the problem lies in? Has anyone have had such a problem before? Any clue or hints are welcome! Is this an known bug of OHCI HC driver usb-ohci in kernel 2.4.21? What makes me more confused is that the Usb Storage Disk works great on the embedded system. I'm using linux-2.4.21 with patch-linux-2.4.21-mh10 and a cirrus edb9312 embedded arm platform which has a OHCI-Compatible USB Host Controller. The bluetooth dongle is a CSR one which works normally on my laptop PC. Thank you in advance, guys. Regards Tianlei -- For the fashion of Minas Tirith was such that it was built on seven levels, each delved into a hill, and about each was set a wall, and in each wall was a gate. -- J.R.R. Tolkien, "The Return of the King" [Quoted in "VMS Internals and Data Structures", V4.4, when referring to system overview.] ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Bluez-devel mailing list Bluez-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bluez-devel