From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261492AbVCNNfo (ORCPT ); Mon, 14 Mar 2005 08:35:44 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261495AbVCNNfo (ORCPT ); Mon, 14 Mar 2005 08:35:44 -0500 Received: from clock-tower.bc.nu ([81.2.110.250]:9377 "EHLO lxorguk.ukuu.org.uk") by vger.kernel.org with ESMTP id S261492AbVCNNfg (ORCPT ); Mon, 14 Mar 2005 08:35:36 -0500 Subject: Re: User mode drivers: part 1, interrupt handling (patch for 2.6.11) From: Alan Cox To: Peter Chubb Cc: Linux Kernel Mailing List In-Reply-To: <16948.54411.754999.668332@wombat.chubb.wattle.id.au> References: <16945.4650.250558.707666@berry.gelato.unsw.EDU.AU> <1110568448.15927.74.camel@localhost.localdomain> <16948.54411.754999.668332@wombat.chubb.wattle.id.au> Content-Type: text/plain Content-Transfer-Encoding: 7bit Message-Id: <1110807209.15943.115.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 (1.4.6-2) Date: Mon, 14 Mar 2005 13:33:31 +0000 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Llu, 2005-03-14 at 00:02, Peter Chubb wrote: > I can see there'd be problems if the code allowed shared interrupts, > but it doesn't. If you don't allow shared IRQ's its useless, if you do allow shared IRQ's it deadlocks. Take your pick 8) As to your comment about needing to do a few more I/O operations I agree. However if your need is for speed then you might want to just write a small IRQ helper module for the kernel or extend the syntax I proposed a little (its conveniently trivial to generate native code from this). There isn't much you can do about the status read without MWI on most chip designs (some get it right by posting status to system memory but not many) Alan