Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761640AbZATV5k (ORCPT ); Tue, 20 Jan 2009 16:57:40 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753597AbZATV50 (ORCPT ); Tue, 20 Jan 2009 16:57:26 -0500 Received: from iabervon.org ([66.92.72.58]:56108 "EHLO iabervon.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753287AbZATV5Y (ORCPT ); Tue, 20 Jan 2009 16:57:24 -0500 Date: Tue, 20 Jan 2009 16:50:41 -0500 (EST) From: Daniel Barkalow To: Mark Lord cc: IDE/ATA development list , Linux Kernel , Tejun Heo , Jeff Garzik , linux-pci@vger.kernel.org Subject: Re: libata, devm_*, and MSI ? In-Reply-To: <4975F5C1.8090107@rtr.ca> Message-ID: References: <4975F5C1.8090107@rtr.ca> User-Agent: Alpine 1.00 (LNX 882 2007-12-20) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1384 Lines: 30 On Tue, 20 Jan 2009, Mark Lord wrote: > Next, there's no mention of a need for invoking pci_intx() in the HOW-TO, > yet some device drivers call it, and others do not. Some devices don't work if you call it (don't send any interrupts); others don't work if you don't call it (send both types of interrupts); most don't care either way. In any case, the core code should deal with it based on quirks. I think there isn't any manufacturer who has had both kinds of quirk, and the clarified spec says that the INTX bit shouldn't matter when MSI is enabled, so manufacturers are slowly converging to that. Initially, the core didn't do anything, and some drivers implemented the need-intx-off quirk; eventually this went into the core as the default behavior. Then some drivers implemented the need-intx-on quirk. Then some common drivers for different hardware turned out to need it both ways, and the core got a real quirk for it. But not all of the drivers have dropped the local setting stuff. The right way to go is to do nothing in the driver and use quirks if you need it. -Daniel *This .sig left intentionally blank* -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/