From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755114AbbATQzY (ORCPT ); Tue, 20 Jan 2015 11:55:24 -0500 Received: from mail-lb0-f172.google.com ([209.85.217.172]:58393 "EHLO mail-lb0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751180AbbATQzX (ORCPT ); Tue, 20 Jan 2015 11:55:23 -0500 Message-ID: <54BE8868.2080101@gmail.com> Date: Tue, 20 Jan 2015 19:55:04 +0300 From: Dmitry Osipenko User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.3.0 MIME-Version: 1.0 To: Stephen Warren , Thierry Reding CC: Alexandre Courbot , Peter De Schrijver , linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH] ARM: tegra20: Store CPU "resettable" status in IRAM References: <1421319545-23920-1-git-send-email-digetx@gmail.com> <1421319545-23920-2-git-send-email-digetx@gmail.com> <20150119141224.GF23778@ulmo.nvidia.com> <54BD3E3E.2040801@wwwdotorg.org> <54BD41D3.7030703@gmail.com> <54BD42D0.3020107@wwwdotorg.org> <54BD4626.70902@gmail.com> <54BD4C42.6090407@gmail.com> In-Reply-To: <54BD4C42.6090407@gmail.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 19.01.2015 21:26, Dmitry Osipenko пишет: > 19.01.2015 21:00, Dmitry Osipenko пишет: >> 19.01.2015 20:45, Stephen Warren пишет: >>> On 01/19/2015 10:41 AM, Dmitry Osipenko wrote: >>>> 19.01.2015 20:26, Stephen Warren пишет: >>>>> Hopefully this works out. I suppose it's unlikely anyone will be >>>>> running code on >>>>> the AVP upstrem, so any potential conflict with AVP's usage of IRAM >>>>> isn't likely >>>>> to occur. >>>>> >>>> I don't see how it can conflict with AVP code. First KB of IRAM is >>>> reserved for reset handler. Am I missing something? >>>> >>>> From reset.h: >>>> >>>> /* The first 1K of IRAM is permanently reserved for the CPU reset >>>> handler */ >>> >>> I believe "CPU" in that context means AVP CPU. Still, I may not be correct, and >>> to be honest it's likely not too well defined even if that comment seems >>> clear-cut. >>> >> Hmm... Suddenly I recalled that LP2 was always disabled in downstream kernel. I >> remember that I tried it once (couple years ago) and it didn't work, however I >> presume it was just broken. Now I don't feel good with it. >> > Can't generic RAM be used for "resettable" status? Or it will be too slow?... > > CPU1 always come up after CPU0, so RAM is already init'ed. Given that CPU0 can't > be halted with running CPU1, I suppose CPU1 can't be booted first, right? Anyway > it's not the case for linux. > Correcting myself: Well, it's meaningless in case if LP2 cpuidle can't co-exist with AVP firmware. Isn't possible verify it? -- Dmitry