From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751091AbVLOVSL (ORCPT ); Thu, 15 Dec 2005 16:18:11 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751096AbVLOVSL (ORCPT ); Thu, 15 Dec 2005 16:18:11 -0500 Received: from sj-iport-2-in.cisco.com ([171.71.176.71]:43057 "EHLO sj-iport-2.cisco.com") by vger.kernel.org with ESMTP id S1751091AbVLOVSK (ORCPT ); Thu, 15 Dec 2005 16:18:10 -0500 To: Benjamin Herrenschmidt Cc: Linux Kernel list , linux-pci Subject: Re: MSI and driver APIs X-Message-Flag: Warning: May contain useful information References: <1134617893.16880.17.camel@gaston> <1134680882.16880.37.camel@gaston> From: Roland Dreier Date: Thu, 15 Dec 2005 13:18:04 -0800 In-Reply-To: <1134680882.16880.37.camel@gaston> (Benjamin Herrenschmidt's message of "Fri, 16 Dec 2005 08:08:02 +1100") Message-ID: User-Agent: Gnus/5.1007 (Gnus v5.10.7) XEmacs/21.4.17 (Jumbo Shrimp, linux) MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 X-OriginalArrivalTime: 15 Dec 2005 21:18:05.0391 (UTC) FILETIME=[09F18DF0:01C601BD] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Benjamin> You can have multiple MSIs too (they just have to be Benjamin> contiguous in numbers and aligned on the nearest power Benjamin> of 2). Good point. I just got too used to the x86-ism of the current MSI code, which can't handle allocating contiguous vectors. Benjamin> I'm tempted to leave them enabled and only disable them Benjamin> when request_irq() is done on the legacy INTx... Does Benjamin> anybody see a problem with this approach ? You might run into trouble on hardware (think tg3 or its ilk again) where you might have to do something beyond disabling MSI in the PCI header to switch the chip out of MSI mode. - R.