From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DF74EC3A59D for ; Fri, 16 Aug 2019 16:15:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C17BA21721 for ; Fri, 16 Aug 2019 16:15:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726345AbfHPQPS (ORCPT ); Fri, 16 Aug 2019 12:15:18 -0400 Received: from emh02.mail.saunalahti.fi ([62.142.5.108]:44832 "EHLO emh02.mail.saunalahti.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726089AbfHPQPS (ORCPT ); Fri, 16 Aug 2019 12:15:18 -0400 Received: from darkstar.musicnaut.iki.fi (85-76-65-201-nat.elisa-mobile.fi [85.76.65.201]) by emh02.mail.saunalahti.fi (Postfix) with ESMTP id 15AB6200D9; Fri, 16 Aug 2019 19:15:14 +0300 (EEST) Date: Fri, 16 Aug 2019 19:15:14 +0300 From: Aaro Koskinen To: Russell King - ARM Linux admin Cc: Linus Walleij , Martin Michlmayr , Peter Teichmann , Arnd Bergmann , "open list:GPIO SUBSYSTEM" , Linux Kernel Mailing List , soc@kernel.org, Bartosz Golaszewski , Vinod Koul , linux-i2c , dmaengine@vger.kernel.org, Dan Williams , Linux ARM Subject: Re: [PATCH 1/7] [RFC] ARM: remove Intel iop33x and iop13xx support Message-ID: <20190816161514.GB30291@darkstar.musicnaut.iki.fi> References: <20190809162956.488941-1-arnd@arndb.de> <20190809163334.489360-1-arnd@arndb.de> <20190812094456.GI10598@jirafa.cyrius.com> <20190816154249.GA30291@darkstar.musicnaut.iki.fi> <20190816155833.GL13294@shell.armlinux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190816155833.GL13294@shell.armlinux.org.uk> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org Hi, On Fri, Aug 16, 2019 at 04:58:33PM +0100, Russell King - ARM Linux admin wrote: > On Fri, Aug 16, 2019 at 06:42:49PM +0300, Aaro Koskinen wrote: > > On Wed, Aug 14, 2019 at 10:36:01AM +0200, Linus Walleij wrote: > > > On Mon, Aug 12, 2019 at 11:45 AM Martin Michlmayr wrote: > > > > As Arnd points out, Debian used to have support for various iop32x > > > > devices. While Debian hasn't supported iop32x in a number of years, > > > > these devices are still usable and in use (RMK being a prime example). > > > > > > I suppose it could be a good idea to add support for iop32x to > > > OpenWrt and/or OpenEmbedded, both of which support some > > > pretty constrained systems. > > > > This platform is not really too constrained... E.g. on N2100 you have > > 512 MB RAM, SATA disks and gigabit ethernet. Not that different from > > mvebu that Debian currently (?) supports. Maybe with multiplatform they > > could support iop32x again. > > Probably not. The kernel has a dividing line between ARMv5 and ARMv6 > where it's not possible to multiplatform across that boundary, so > you're already needing separate kernel images there. > > Secondly, armhf distros won't be compatible with ARMv5, and to make > them compatible will make performance on armhf suffer - you have to > stop using barriers, exclusive load/store and a few other things. > You have to rely on the kuser page exported by the kernel (which is > now optional as it's deemed to be a security issue for ROP attacks) > for some things that such a userspace requires - such as NPTL support. > > Effectively, ARMv5 is an entirely separate userspace distro from armhf. I thought they still had armel for ARMv5 and mvebu (kirkwood). A.