Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751687AbaJDKPt (ORCPT ); Sat, 4 Oct 2014 06:15:49 -0400 Received: from pegase1.c-s.fr ([93.17.236.30]:40719 "EHLO mailhub1.si.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750780AbaJDKPr (ORCPT ); Sat, 4 Oct 2014 06:15:47 -0400 Message-ID: <542FC8C1.1000707@c-s.fr> Date: Sat, 04 Oct 2014 12:15:29 +0200 From: christophe leroy User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: Scott Wood CC: Mark Brown , Benjamin Herrenschmidt , Paul Mackerras , Marcelo Tosatti , Vitaly Bordug , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-spi@vger.kernel.org, Joakim Tjernlund Subject: Re: [PATCH 2/2] spi: fsl-spi: Allow dynamic allocation of CPM1 parameter RAM References: <20141003125609.5BEA11AB276@localhost.localdomain> <20141003144420.GC24441@sirena.org.uk> <542F03CF.8010900@c-s.fr> <1412367858.13320.432.camel@snotra.buserror.net> In-Reply-To: <1412367858.13320.432.camel@snotra.buserror.net> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Antivirus: avast! (VPS 141004-0, 04/10/2014), Outbound message X-Antivirus-Status: Clean Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le 03/10/2014 22:24, Scott Wood a écrit : > On Fri, 2014-10-03 at 22:15 +0200, christophe leroy wrote: >> Le 03/10/2014 16:44, Mark Brown a écrit : >>> On Fri, Oct 03, 2014 at 02:56:09PM +0200, Christophe Leroy wrote: >>> >>>> +config CPM1_RELOCSPI >>>> + bool "Dynamic SPI relocation" >>>> + default n >>>> + help >>>> + On recent MPC8xx (at least MPC866 and MPC885) SPI can be relocated >>>> + without micropatch. This activates relocation to a dynamically >>>> + allocated area in the CPM Dual port RAM. >>>> + When combined with SPI relocation patch (for older MPC8xx) it avoids >>>> + the "loss" of additional Dual port RAM space just above the patch, >>>> + which might be needed for example when using the CPM QMC. >>> Something like this shouldn't be a compile time option. Either it >>> should be unconditional or it should be triggered in some system >>> specific manner (from DT, from knowing about other users or similar). >> Can't be unconditional as older versions of mpc8xx (eg MPC860) don't >> support relocation without a micropatch. >> I have therefore submitted a v2 based on a DTS compatible property. > So the device tree change is about whether relocation is supported, not > whether it is required? Indeed no, my intension is to say that relocation is requested. Do you mean that it should then not use a compatible ? > Is this specific to SPI or does the relocation > mechanism work for other things? Relocation is the same for I2C. It is also possible to relocate SMC1 and SMC2 parameter RAM but only with a micropatch. Today, the kernel only implements relocation of SMC1, and it relocates it at a fixed address just after SMC2 at offset 0x1FC0. > > How about checking for the existing specific-SoC compatibles? What do you mean ? Christophe --- Ce courrier électronique ne contient aucun virus ou logiciel malveillant parce que la protection avast! Antivirus est active. http://www.avast.com -- 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/