From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030307AbWGMTWA (ORCPT ); Thu, 13 Jul 2006 15:22:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030304AbWGMTV7 (ORCPT ); Thu, 13 Jul 2006 15:21:59 -0400 Received: from ebiederm.dsl.xmission.com ([166.70.28.69]:23783 "EHLO ebiederm.dsl.xmission.com") by vger.kernel.org with ESMTP id S1030305AbWGMTV6 (ORCPT ); Thu, 13 Jul 2006 15:21:58 -0400 From: ebiederm@xmission.com (Eric W. Biederman) To: olson@pathscale.com Cc: Andi Kleen , linux-kernel@vger.kernel.org, Benjamin Herrenschmidt , discuss@x86-64.org Subject: Re: [PATCH 2/2] Initial generic hypertransport interrupt support. References: Date: Thu, 13 Jul 2006 13:20:59 -0600 In-Reply-To: (Dave Olson's message of "Thu, 13 Jul 2006 12:00:59 -0700 (PDT)") Message-ID: User-Agent: Gnus/5.110004 (No Gnus v0.4) Emacs/21.4 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Dave Olson writes: > On Thu, 13 Jul 2006, Eric W. Biederman wrote: > | > There's really nothing special at all about the interrupt > | > setup, except in one very minor way. The value of the HT interrupt > | > destination address needs to be copied from HT config space, to > | > an internal chip register (which is, can, and should be, handled by > | > the driver init code). > | > | The kernel changes the value at runtime, based upon user input. > | I assume your mirror register needs to be updated after every change. > > Yes. If the interrupt address changes, then we need a callback. > > | Since the kernel changes the value at runtime, and since a different > | register needs to be written to, I can't quite use the generic code I > | have written as is. > > I imagine at least some other drivers would like to know when their interrupt > configuration changes, also, so an interface where a driver can register > a callback handler seems like the right generic answer, or more simply, > a way for a driver to say it doesn't want it's interrupt handler > migrated (which we would like anyway, for performance reasons). As I recall that is "killall irqbalanced" Eric