From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Qiu Subject: Re: BCM5719(tg3) use multiple MSI with RSS Date: Thu, 16 May 2013 10:30:36 +0800 Message-ID: <519444CC.6080406@linux.vnet.ibm.com> References: <51933FCB.4090402@linux.vnet.ibm.com> <1368630538.3768.12.camel@LTIRV-MCHAN1.corp.ad.broadcom.com> <1368633120.2652.11.camel@bwh-desktop.uk.solarflarecom.com> <1368633836.6796.1.camel@LTIRV-MCHAN1.corp.ad.broadcom.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Ben Hutchings , eilong@broadcom.com, mcarlson@broadcom.com, zambrano@broadcom.com, jeffrey.t.kirsher@intel.com, netdev@vger.kernel.org To: Michael Chan Return-path: Received: from e28smtp07.in.ibm.com ([122.248.162.7]:36860 "EHLO e28smtp07.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751887Ab3EPCas (ORCPT ); Wed, 15 May 2013 22:30:48 -0400 Received: from /spool/local by e28smtp07.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 16 May 2013 07:55:03 +0530 Received: from d28relay03.in.ibm.com (d28relay03.in.ibm.com [9.184.220.60]) by d28dlp03.in.ibm.com (Postfix) with ESMTP id E62901258023 for ; Thu, 16 May 2013 08:02:35 +0530 (IST) Received: from d28av05.in.ibm.com (d28av05.in.ibm.com [9.184.220.67]) by d28relay03.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r4G2UZtC66912480 for ; Thu, 16 May 2013 08:00:35 +0530 Received: from d28av05.in.ibm.com (loopback [127.0.0.1]) by d28av05.in.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r4G2UfpG028206 for ; Thu, 16 May 2013 12:30:43 +1000 In-Reply-To: <1368633836.6796.1.camel@LTIRV-MCHAN1.corp.ad.broadcom.com> Sender: netdev-owner@vger.kernel.org List-ID: =E4=BA=8E 2013/5/16 0:03, Michael Chan =E5=86=99=E9=81=93: > On Wed, 2013-05-15 at 16:52 +0100, Ben Hutchings wrote: >> On Wed, 2013-05-15 at 08:08 -0700, Michael Chan wrote: >>> On Wed, 2013-05-15 at 15:56 +0800, Mike Qiu wrote: >>>> Hi all >>>> >>>> Currently, I need to enable multiple MSI on BCM5719 network card. >>>> But I look in to the spec of 5719 from Broadcom, it seems >>>> that RSS just enable with MSI-X, so I'm not sure if multiple >>>> MSI can use RSS. >>>> >>> MSI can only support one IRQ source and cannot support RSS. >> It is possible for an MSI capability to have multiple MSIs, but they >> will use the same address and consecutive data values. >> >> On x86, if you can find a large enough block of free IRQs on an IOAP= IC, >> it is possible to implement RSS this way. Linux supports this on >> systems with an x2apic. >> >> Now, maybe tg3 hardware doesn't support this (and really, why bother >> when there is MSI-X?) but the option does exist. > Yes, tg3 hardware (may be all Broadcom hardware) can only use MSI as = a > replacement for INTA. That you mean, it can't use multiple MSI for RSS ? >