Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752729AbdF2Puc (ORCPT ); Thu, 29 Jun 2017 11:50:32 -0400 Received: from mail-oi0-f66.google.com ([209.85.218.66]:34928 "EHLO mail-oi0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751861AbdF2PuY (ORCPT ); Thu, 29 Jun 2017 11:50:24 -0400 MIME-Version: 1.0 In-Reply-To: <6d9d0d63-113e-b050-a54e-62746ebc6013@suse.de> References: <20170606005426.26446-1-afaerber@suse.de> <20170606005426.26446-21-afaerber@suse.de> <6d9d0d63-113e-b050-a54e-62746ebc6013@suse.de> From: Arnd Bergmann Date: Thu, 29 Jun 2017 17:50:15 +0200 X-Google-Sender-Auth: aH31SArrs8b5Q5GZlPK1pUKztbI Message-ID: Subject: Re: [PATCH v4 20/28] ARM: owl: Implement CPU enable-method for S500 To: =?UTF-8?Q?Andreas_F=C3=A4rber?= Cc: Thomas Liau , Linux ARM , mp-cs@actions-semi.com, =?UTF-8?B?5byg5Lic6aOO?= , =?UTF-8?B?5YiY54Kc?= , =?UTF-8?B?5byg5aSp55uK?= , 96boards@ucrobotics.com, support@lemaker.org, Linux Kernel Mailing List , Russell King Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by mail.home.local id v5TFofkY010392 Content-Length: 1015 Lines: 23 On Thu, Jun 29, 2017 at 5:22 PM, Andreas Färber wrote: > Am 29.06.2017 um 17:07 schrieb Arnd Bergmann: >> >> It seems you missed my question here. Can you please follow up, and >> if possible send a patch to remove the pen_release logic that appears >> to be unnecessary here? > > I do not have any documentation on these registers, only the downstream > code that I forward-ported here. If you tell me what you mean exactly, I > can do some testing and if it still works submit a patch to simplify it. > > Comments from the so far quiet Actions Semi side would help, too. IIRC, there are two ways to implement SMP bootup: either you have registers to tell the secondary CPU how to start up out of reset or they get put into a holding pen during early boot where they spin waiting for a variable to get written. However, doing both is not necessary. See for example mach-sunxi for an example without the holding pen. I think you can just delete half of your file to do the same. Arnd