From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030235AbWGMTBA (ORCPT ); Thu, 13 Jul 2006 15:01:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030290AbWGMTBA (ORCPT ); Thu, 13 Jul 2006 15:01:00 -0400 Received: from mx.pathscale.com ([64.160.42.68]:30090 "EHLO mx.pathscale.com") by vger.kernel.org with ESMTP id S1030235AbWGMTA7 (ORCPT ); Thu, 13 Jul 2006 15:00:59 -0400 Date: Thu, 13 Jul 2006 12:00:59 -0700 (PDT) From: Dave Olson Reply-To: olson@pathscale.com To: "Eric W. Biederman" Cc: Andi Kleen , linux-kernel@vger.kernel.org, Benjamin Herrenschmidt , discuss@x86-64.org Subject: Re: [PATCH 2/2] Initial generic hypertransport interrupt support. In-Reply-To: Message-ID: References: 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 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). Dave Olson dave.olson@qlogic.com