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 10:25:32 +0800 Message-ID: <5194439C.2050509@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> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Michael Chan , eilong@broadcom.com, mcarlson@broadcom.com, zambrano@broadcom.com, jeffrey.t.kirsher@intel.com, netdev@vger.kernel.org To: Ben Hutchings Return-path: Received: from e28smtp03.in.ibm.com ([122.248.162.3]:36768 "EHLO e28smtp03.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755027Ab3EPCZp (ORCPT ); Wed, 15 May 2013 22:25:45 -0400 Received: from /spool/local by e28smtp03.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 16 May 2013 07:50:49 +0530 Received: from d28relay04.in.ibm.com (d28relay04.in.ibm.com [9.184.220.61]) by d28dlp03.in.ibm.com (Postfix) with ESMTP id 217EB1258051 for ; Thu, 16 May 2013 07:57:31 +0530 (IST) Received: from d28av05.in.ibm.com (d28av05.in.ibm.com [9.184.220.67]) by d28relay04.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r4G2PWe214025046 for ; Thu, 16 May 2013 07:55:32 +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 r4G2PbhP012212 for ; Thu, 16 May 2013 12:25:37 +1000 In-Reply-To: <1368633120.2652.11.camel@bwh-desktop.uk.solarflarecom.com> Sender: netdev-owner@vger.kernel.org List-ID: =E4=BA=8E 2013/5/15 23:52, Ben Hutchings =E5=86=99=E9=81=93: > 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. Yes, it should be this. > On x86, if you can find a large enough block of free IRQs on an IOAPI= C, > it is possible to implement RSS this way. Linux supports this on > systems with an x2apic. But, I see the tg3 spec, and it seems the RSS is just for MSI-X(and IOV= ). And I try to enable RSS use multiple MSI for 4 irqs, the system alloc 4 consecutive irqs to tg3, and each one can be test pass using=20 interrupt test. But the last 3 interrupts seems not to be triggered as "cat /proc/inter= rups" shows after the driver loaded. Only the first irq can be triggered for only sometimes. The network surely not work. > Now, maybe tg3 hardware doesn't support this (and really, why bother > when there is MSI-X?) but the option does exist. Actually, I try to enable the multiple MSI feature, and needs tg3 card = to support this feature. For some old PCI device, it may only support=20 multiple MSI Thanks Mike > > Ben. >