From mboxrd@z Thu Jan 1 00:00:00 1970 From: bugme-daemon@bugzilla.kernel.org Subject: [Bug 12730] USB memory stick moved to different device on error / may be due to problem with high concurrent load on two USB devices Date: Wed, 18 Feb 2009 07:19:34 -0800 (PST) Message-ID: <20090218151934.A904C10803F@picon.linux-foundation.org> References: Return-path: Received: from smtp1.linux-foundation.org ([140.211.169.13]:56314 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752848AbZBRPTx (ORCPT ); Wed, 18 Feb 2009 10:19:53 -0500 Received: from picon.linux-foundation.org (picon.linux-foundation.org [140.211.169.79]) by smtp1.linux-foundation.org (8.14.2/8.13.5/Debian-3ubuntu1.1) with ESMTP id n1IFJYmv025861 for ; Wed, 18 Feb 2009 07:19:36 -0800 In-Reply-To: Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: linux-scsi@vger.kernel.org http://bugzilla.kernel.org/show_bug.cgi?id=12730 stern@rowland.harvard.edu changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |stern@rowland.harvard.edu ------- Comment #2 from stern@rowland.harvard.edu 2009-02-18 07:19 ------- Unfortunately, a lot of EHCI hardware seems to have trouble carrying out transfers over different ports concurrently. Your log doesn't contain enough information to tell just what happened. If you want more information, you can build a kernel with CONFIG_USB_DEBUG enabled. There may or may not have been an actual USB disconnect. (Such an electronic disconnect is indeed indistinguishable from a physical unplug.) The log shows that the 1-2 drive got into an error state requiring a reset; quite possibly the reset failed. This leaves the kernel no choice but to carry out a "logical" disconnect. While it's not exactly the same as a physical disconnect, it is treated the same way and so it is indistinguishable as far as most of the kernel is concerned. It's impossible to tell whether the error state was caused by the drive or by the EHCI controller. To find out for certain, you'd have to use a USB bus analyzer. -- Configure bugmail: http://bugzilla.kernel.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are the assignee for the bug, or are watching the assignee.