Bug#308098: acknowledged by developer (Re: Bug#308098: libsane: fail my canon N650U on USB hub, works fine without the hub)

[Jean-Louis MOUNIER]

Debian Bug Tracking System a écrit : This is an automatic notification regarding your Bug report #308098: libsane: fail my canon N650U on USB hub, works fine without the hub, which was filed against the libsane package. It has been closed by one of the developers, namely Julien BLACHE <[EMAIL PROTECTED]>. Their explanation is attached below. If this explanation is unsatisfactory and you have not received a better one in a separate message then please contact the developer, by replying to this email. Debian bug tracking system administrator (administrator, Debian Bugs database) Received: (at 308098-done) by bugs.debian.org; 8 May 2005 08:15:21 +0000 >From [EMAIL PROTECTED] Sun May 08 01:15:21 2005 Return-path: <[EMAIL PROTECTED]> Received: from sardaukar.technologeek.org (frigate.technologeek.org) [213.41.134.11] by spohr.debian.org with esmtp (Exim 3.35 1 (Debian)) id 1DUgwb-0006AP-00; Sun, 08 May 2005 01:15:21 -0700 Received: by frigate.technologeek.org (Postfix, from userid 1000) id A78571475752; Sun, 8 May 2005 10:14:48 +0200 (CEST) To: [EMAIL PROTECTED] Subject: Re: Bug#308098: libsane: fail my canon N650U on USB hub, works fine without the hub References: <[EMAIL PROTECTED]> From: Julien BLACHE <[EMAIL PROTECTED]> Date: Sun, 08 May 2005 10:14:48 +0200 In-Reply-To: <[EMAIL PROTECTED]> (Jean-Louis Mounier's message of "Sat, 07 May 2005 22:58:21 +0200") Message-ID: <[EMAIL PROTECTED]> User-Agent: Gnus/5.1006 (Gnus v5.10.6) XEmacs/21.4 (Jumbo Shrimp, linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Delivered-To: [EMAIL PROTECTED] X-Spam-Checker-Version: SpamAssassin 2.60-bugs.debian.org_2005_01_02 (1.212-2003-09-23-exp) on spohr.debian.org X-Spam-Status: No, hits=-6.0 required=4.0 tests=BAYES_00,HAS_BUG_NUMBER autolearn=no version=2.60-bugs.debian.org_2005_01_02 X-Spam-Level: Jean-Louis Mounier <[EMAIL PROTECTED]> wrote: The scanner works fine when plugged directly on the PC, it fails when using a USB HUB betwwen the scanner and the PC. I get a device IO error. with "cat /proc/bus/usb/devices", I get "driver=none" for the scanner. Then the USB hub you use is the problem. Simple, really. If your scanner is bus-powered, and your USB hub didn't come with an AC adapter of its own, then your scanner can't get enough power from the USB bus and there's nothing the software can do to get it to work. Get an AC adapter for your hub if possible, or get one for the scanner if possible, or get another, less crappy, USB hub. JB. Bonjour Julien, Sorry folk, it was late and I didn't realize that the power consumption of the hub is 100mA and the hub uses 500mA . So the hub needed to be self powered (the scanner doesn't have power supply, which is very practical). After plugging the hub power supply, all works fine. The bug can be closed. The main lesson would be to improve error detection on USB, the scanner was detected by sane-find-scanner but was not usable, that is what made me submit this (my first ) bug report. . Thank you