From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by dpdk.org (Postfix) with ESMTP id 1C4198DA2 for ; Wed, 28 Oct 2015 14:44:55 +0100 (CET) Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga101.jf.intel.com with ESMTP; 28 Oct 2015 06:44:55 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.20,210,1444719600"; d="scan'208";a="837532572" Received: from dhunt5x-mobl3.ger.corp.intel.com (HELO [10.237.208.62]) ([10.237.208.62]) by fmsmga002.fm.intel.com with ESMTP; 28 Oct 2015 06:44:51 -0700 To: Jan Viktorin , David Marchand References: <1445877458-31052-1-git-send-email-viktorin@rehivetech.com> <1445973229-22058-1-git-send-email-viktorin@rehivetech.com> <1445973229-22058-2-git-send-email-viktorin@rehivetech.com> <20151028115606.74fb2fb8@jvn> From: "Hunt, David" Message-ID: <5630D152.3000003@intel.com> Date: Wed, 28 Oct 2015 13:44:50 +0000 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <20151028115606.74fb2fb8@jvn> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Cc: "dev@dpdk.org" , Vlastimil Kosar Subject: Re: [dpdk-dev] [PATCH v3 01/17] mk: Introduce ARMv7 architecture X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 28 Oct 2015 13:44:56 -0000 On 28/10/2015 10:56, Jan Viktorin wrote: > On Wed, 28 Oct 2015 11:09:21 +0100 > David Marchand wrote: > >> Hello Jan, >> >> On Tue, Oct 27, 2015 at 8:13 PM, Jan Viktorin >> wrote: >> >> +# PCI is usually not used on ARM >>> +CONFIG_RTE_EAL_IGB_UIO=n >>> >> >> Not sure "usually not used" is a good reason to disable something. >> Is there a real issue on arm with igb_uio code (compilation, pci accesses) ? >> > > Well, it requires to set some options in Linux Kernel (at least PCI > support) which are usually disabled by the in-kernel *arm*_defconfigs. > Moreover, it seems I cannot enable it for some ARM architectures (I've > tried Altera SoC FPGA). That's because you hardly find an ARMv7 system > with a PCI bus. I suppose that if somebody _really_ needs this, she would > enable it by hand. > > At the moment, it breaks my common builds... The driver is mostly > useless on ARMv7 and just takes space in the filesystem. I have an ARMv8 board here that I've built a new kernel for the purposes of an ARMv8 port, and it took quite a while to get the PCI functionality all working, including implementing a fix to the kernel PCI driver to expose the mmap resources in sysfs properly. But after that, igb_uio compiles fine (on the ARMv8 patch) and works with a Niantic to pass traffic between ports. If the majority of ARMv7 boards don't have a PCI bus, then I'd suggest leaving igb_uio disabled. Those few boards with PCI will most likely have a correctly kernel (and source) ready to go, so enabling igb_uio for them will be easy, but disabling seems a more sensible default for the majority of ARMv7 users. Rgds, Dave.