From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262866AbUB0Nbw (ORCPT ); Fri, 27 Feb 2004 08:31:52 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262871AbUB0Nbw (ORCPT ); Fri, 27 Feb 2004 08:31:52 -0500 Received: from nsmtp.pacific.net.th ([203.121.130.117]:4281 "EHLO nsmtp.pacific.net.th") by vger.kernel.org with ESMTP id S262866AbUB0Nbv (ORCPT ); Fri, 27 Feb 2004 08:31:51 -0500 Date: Fri, 27 Feb 2004 21:31:43 +0800 From: "Michael Frank" To: "Russell King" Subject: Re: Why no interrupt priorities? Cc: "Benjamin Herrenschmidt" , "Grover, Andrew" , "Mark Gross" , arjanv@redhat.com, "Tim Bird" , root@chaos.analogic.com, "Linux Kernel list" References: <1077859968.22213.163.camel@gaston> <20040227090548.A15644@flint.arm.linux.org.uk> Content-Type: text/plain; charset=US-ASCII; format=flowed delsp=yes MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Message-ID: In-Reply-To: <20040227090548.A15644@flint.arm.linux.org.uk> User-Agent: Opera M2/7.50 (Linux, build 600) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 27 Feb 2004 09:05:48 +0000, Russell King wrote: > On Fri, Feb 27, 2004 at 02:26:31PM +0800, Michael Frank wrote: >> Is this to imply that edge triggered shared interrupts are used anywhere? > > It is (or used to be) rather common with serial ports. Remember that > COM1 and COM3 were both defined to use IRQ4 and COM2 and COM4 to use > IRQ3. > >> Never occured to me to use shared IRQ's edge triggered as this mode >> _cannot_ work reliably for HW limitations. > > The serial driver takes great care with this - when we service such an > interrupt, we keep going until we have scanned all the devices until > such time that we can say "all devices are no longer signalling an > interrupt". > > This is something it has always done - it's nothing new. > Sorry, i think the serial driver IRQ is level triggered :) Regards Michael