Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755568AbbBLOtD (ORCPT ); Thu, 12 Feb 2015 09:49:03 -0500 Received: from mail-pa0-f51.google.com ([209.85.220.51]:36140 "EHLO mail-pa0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752766AbbBLOtB (ORCPT ); Thu, 12 Feb 2015 09:49:01 -0500 Date: Thu, 12 Feb 2015 06:48:55 -0800 From: Stephen Hemminger To: Andrey Utkin Cc: "linux-kernel@vger.kernel.org" , kernelnewbies , "kernel-mentors@selenic.com" Subject: Re: Question on MSI support in PCI and PCI-E devices Message-ID: <20150212064855.5d7ac655@uryu.home.lan> In-Reply-To: References: X-Mailer: Claws Mail 3.11.1 (GTK+ 2.24.25; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 814 Lines: 19 On Wed, 11 Feb 2015 18:19:00 +0000 Andrey Utkin wrote: > Is it true that _every_ PCI or PCI Express device supporting MSI is > indicated by some mention of MSI in "lspci -v", and if there's no such > mention, it surely doesn't support MSI? > Look at kernel source (drivers/pci/msi.c) function pci_msi_supported there are many things which can block MSI. There can be cases where PCI quirks in kernel block MSI because for example the device supports MSI, but the motherboard BIOS is broken. This only happens on really old systems. -- 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/