Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757549AbZF3VBQ (ORCPT ); Tue, 30 Jun 2009 17:01:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755643AbZF3VA7 (ORCPT ); Tue, 30 Jun 2009 17:00:59 -0400 Received: from iolanthe.rowland.org ([192.131.102.54]:57799 "HELO iolanthe.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1753849AbZF3VA6 (ORCPT ); Tue, 30 Jun 2009 17:00:58 -0400 Date: Tue, 30 Jun 2009 17:01:00 -0400 (EDT) From: Alan Stern X-X-Sender: stern@iolanthe.rowland.org To: Arseniy Lartsev cc: Oliver Neukum , USB list , Subject: Re: PROBLEM: USB ACM device does not work In-Reply-To: <200907010009.51237.ars3n@yandex.ru> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1358 Lines: 29 On Wed, 1 Jul 2009, Arseniy Lartsev wrote: > On Tuesday 30 June 2009 11:22:04 Oliver Neukum wrote: > > Yet, your device shows bulk endpoints. Please enable DEBUG in cdc-acm.c > > and recompile with CONFIG_USB_DEBUG. > > I've recompiled four modules usbcore, ehci_hcd, ohci_hcd and cdc-acm with -DDEBUG. > Here is kernel log: > > ======================== Device plugged in ======================== ... > Jun 30 23:58:35 noteb00k kernel: usb 2-3: new low speed USB device using ohci_hcd and address 5 ... > Jun 30 23:58:35 noteb00k kernel: usb 2-3: config 1 interface 1 altsetting 0 endpoint 0x1 is Bulk; changing to > Interrupt > Jun 30 23:58:35 noteb00k kernel: usb 2-3: config 1 interface 1 altsetting 0 endpoint 0x81 is Bulk; changing to > Interrupt This looks like your problem. Low-speed devices are not allowed to have bulk endpoints. Linux internally changes them to interrupt endpoints with interval = 1 and maxpacket size no larger than 8. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/