From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751268AbWFFLlQ (ORCPT ); Tue, 6 Jun 2006 07:41:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751257AbWFFLlQ (ORCPT ); Tue, 6 Jun 2006 07:41:16 -0400 Received: from server1.meinberg.de ([85.10.202.66]:33669 "EHLO paolo.meinberg.de") by vger.kernel.org with ESMTP id S1751279AbWFFLlP (ORCPT ); Tue, 6 Jun 2006 07:41:15 -0400 Message-ID: <448569CE.1020906@meinberg.de> Date: Tue, 06 Jun 2006 13:41:02 +0200 From: Heiko Gerstung Organization: Meinberg Radio Clocks User-Agent: Thunderbird 1.5.0.2 (X11/20060601) MIME-Version: 1.0 To: Jesper Juhl CC: linux-kernel@vger.kernel.org Subject: Re: Backport of a 2.6.x USB driver to 2.4.32 - help needed References: <44854F74.50406@meinberg.de> <9a8748490606060423t102384f4m626b4366898ce9cd@mail.gmail.com> In-Reply-To: <9a8748490606060423t102384f4m626b4366898ce9cd@mail.gmail.com> X-Enigmail-Version: 0.94.0.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Jesper Juhl wrote: > in_atomic() is used to test if the kernel is in a state where sleeping > is allowed or not. The 2.4.x kernel is not preemptive and has quite > coarse grained SMP support (the BKL "Big Kernel Lock"), it didin't > need in_atomic() in the same way as 2.6.x does. OK, so I guess I can safely ommit this. > schedule_timeout_uninterruptible() is used to sleep on a wait-queue, > which 2.4.x does not have. Is there any similiar functionality in a 2.4 kernel environment? A pointer to a 2.4 kernel driver using such a mechanism would be a good starter... > [snip] > Wouldn't it make more sense to work on improving PPS (I assume you are > refering to NTP "pulse per second" btw) support in 2.6.x rather than > backporting an USB driver to 2.4.x ??? Yes, but unfortunately I have no chance to do this and therefore I rely on others to do this. Well, the same applies to [me] and [kernel drivers], but I hoped that it might be easier to try and backport one driver instead of trying to improve other people's code (maybe that is what OPC stands for :-)), especially when this code has a much larger impact on several parts of the kernel. > [snip] > The book "Linux Device Drivers" third edition is available for free > online and describes 2.6.x USB drivers in a fair bit of detail. > Earlier editions of the book describe the 2.4.x kernel (don't know if > those are available for free, but it should be possible to get them > from a bookstore in any case). > > Getting hold of the second & third editions of LDD and comparing the > USB info from both should give you some idea of where to start... OK, I will try to do so, but I am afraid that I will run out of time in the meantime. Thank you very much for your help and your fast response. Kind regards, Heiko -- ------------------------------------------------------------------------ *MEINBERG Funkuhren GmbH & Co. KG* Auf der Landwehr 22 D-31812 Bad Pyrmont, Germany Tel.: ++49 (0)5281 9309-25 Fax: ++49 (0)5281 9309-30 eMail: heiko.gerstung@meinberg.de Internet: www.meinberg.de ------------------------------------------------------------------------ Meinberg radio clocks: 25 years of accurate time worldwide