From owner-freebsd-net@FreeBSD.ORG Sun Dec 30 17:11:17 2007 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id DB6B816A419 for ; Sun, 30 Dec 2007 17:11:17 +0000 (UTC) (envelope-from rwatson@FreeBSD.org) Received: from cyrus.watson.org (cyrus.watson.org [209.31.154.42]) by mx1.freebsd.org (Postfix) with ESMTP id 89FB913C4CE for ; Sun, 30 Dec 2007 17:11:17 +0000 (UTC) (envelope-from rwatson@FreeBSD.org) Received: from fledge.watson.org (fledge.watson.org [209.31.154.41]) by cyrus.watson.org (Postfix) with ESMTP id 8B35C47125; Sun, 30 Dec 2007 12:11:16 -0500 (EST) Date: Sun, 30 Dec 2007 17:11:16 +0000 (GMT) From: Robert Watson X-X-Sender: robert@fledge.watson.org To: Tofig Suleymanov In-Reply-To: <4777690B.1030403@freebsd.az> Message-ID: <20071230170217.T6382@fledge.watson.org> References: <4777690B.1030403@freebsd.az> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: freebsd-net@freebsd.org Subject: Re: if_start running deferred for Giant X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 30 Dec 2007 17:11:17 -0000 On Sun, 30 Dec 2007, Tofig Suleymanov wrote: > I am writing a driver for Kyocera USB modem for FreeBSD and there are a few > questions that I am not able to solve alone. I would be grateful if someone > could point me into the right direction.Here is the first one: > > Inside the USB_ATTACH() function I initialise the ifnet(9) structure and > return USB_ATTACH_SUCCESS_RETURN. Everything seems to be fine so far (I can > see the interface in ifconfig output) except the following error notice spit > to the console: > > xxxxxx kernel: ib0: if_start running deferred for Giant > > I am not sure what does this exactly mean. > > Any help would be appreciated. This occurs when a network device driver has declared itself IFF_NEEDSGIANT -- that is, has declared that it requires the Giant lock in order to operate. As this is considered an undesirable state of affairs for a device driver, a warning is printed. However, in the case of a USB device driver, it is currently required as the USB framework is not MPSAFE, so requires Giant. Robert N M Watson Computer Laboratory University of Cambridge