Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761060AbXEZPFh (ORCPT ); Sat, 26 May 2007 11:05:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755641AbXEZPF3 (ORCPT ); Sat, 26 May 2007 11:05:29 -0400 Received: from mu-out-0910.google.com ([209.85.134.191]:16189 "EHLO mu-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754915AbXEZPF3 (ORCPT ); Sat, 26 May 2007 11:05:29 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:user-agent:mime-version:to:cc:subject:references:in-reply-to:content-type:content-transfer-encoding; b=IiHD7mgbJJMQpWbVIsL0Edw3SeqCVZZ2AdSMnaQcf+Y6ku7DnFXYGUlLIPPND/uieubW2+wOJh17IQoi9K/FagW8H714XzPa70MGF1Msy5t93zJvCm7zRfdRRnBTsWBQSRyMAyAL4ASR4lkLyNgyqguUtv5rT1e7ggFieY9r0s0= Message-ID: <46584C30.4030206@gmail.com> Date: Sat, 26 May 2007 19:03:12 +0400 From: Manu Abraham User-Agent: Thunderbird 1.5.0.10 (X11/20070306) MIME-Version: 1.0 To: Roland Dreier CC: Greg KH , linux-pci@atrey.karlin.mff.cuni.cz, linux-kernel Subject: Re: PCIE References: <46543045.3030904@gmail.com> <20070523155958.GA5282@kroah.com> <4654AB40.6060208@gmail.com> <4654BC10.2000808@gmail.com> <4654C85B.6060505@gmail.com> <46561287.8020103@gmail.com> In-Reply-To: Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1247 Lines: 30 Roland Dreier wrote: > > I am now wondering whether the usage of MSI would help in this case and > > that i should be using enable_msi before request_irq ? > > MSI interrupts are never shared. So if pci_enable_msi() succeeds, you > can be sure that the interrupts you get with that IRQ number are > coming from your device. > i presume then i shouldn't be using IRQF_SHARED, if using MSI. Another question would be if the device supports multiple messages, MSIX should be used ? In such a context, if i request for say more than the messages that i need, say i request 16 messages, but use only 1 or 2, that does bear any consequences ? > But using MSI does not work on all systems, so your driver needs to > work with standard (possibly shared) INTx interrupts too. And you > should probably provide at least a module flag to disable the use of > MSI, to avoid problems on buggy systems. I should probably look for CONFIG_PCI_MSI and check whether the system supports MSI pci_enable_msi() ? - 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/