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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 21AEBC43441 for ; Wed, 28 Nov 2018 09:28:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D877E208E7 for ; Wed, 28 Nov 2018 09:28:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D877E208E7 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-m68k.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728217AbeK1U3i (ORCPT ); Wed, 28 Nov 2018 15:29:38 -0500 Received: from mail-ua1-f68.google.com ([209.85.222.68]:35281 "EHLO mail-ua1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727713AbeK1U3h (ORCPT ); Wed, 28 Nov 2018 15:29:37 -0500 Received: by mail-ua1-f68.google.com with SMTP id d2so8665900ual.2; Wed, 28 Nov 2018 01:28:38 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=CYAaP/4fD9Qb83tznyfqPwnDk3lPTPLvLdfGLagzl5o=; b=jaTdFTHele+aTWLF4PXc5tbXRBGjtJQ/uFiVo1PVWNxsRgQTFkTSyaD0ahYGLjQrPS TM5iMUOjajjRzRu+Y7hDjJ0q5/d5DcFHKYRS9jeDPg9ogzoZ01wtb7UXW39WTvKHX7dX IM8zdaSecRsRqdon8LWs4EQ0femtJuB0ismyAYq7NcR0xrNmpJrgBfdHGCAwQCPndtXc EzgmFBrH0oGo7+j5t5jMjq3hqU6kZfC16dsAWM4mfRbkK+KXRgXxjVJPbA5aOijKvGG4 Q50xRdNKcOU2f8UEwLMwXUjIuwujkek0R+1Er3BXV1m5TYZ+Api7D27YS31LsAlbQJJm p++Q== X-Gm-Message-State: AA+aEWZ56fwrYzjVJNUCeBvsYqoLN5CF1ntxb8aK834DQc4Es9kPPlSj 47b13CGSO/QlRF+sbHpfnvwskavFS2TKq8CARb4= X-Google-Smtp-Source: AFSGD/WOF5kifEo5Myop6f8/8yJrkwycU1KBVQKtXVQElMm6SeFWDzeINd2AfsKsQiHDYTgdjeG4y/LKrVPkSJ/VGEM= X-Received: by 2002:ab0:210e:: with SMTP id d14mr15145281ual.20.1543397318241; Wed, 28 Nov 2018 01:28:38 -0800 (PST) MIME-Version: 1.0 References: <20181113133520.20889-1-geert+renesas@glider.be> In-Reply-To: <20181113133520.20889-1-geert+renesas@glider.be> From: Geert Uytterhoeven Date: Wed, 28 Nov 2018 10:28:25 +0100 Message-ID: Subject: Re: [PATCH v3] reset: Exclusive resets must be dedicated to a single hardware block To: Mark Rutland , Rob Herring Cc: Philipp Zabel , Geert Uytterhoeven , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , Linux-Renesas , Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 13, 2018 at 2:35 PM Geert Uytterhoeven wrote: > In some SoCs multiple hardware blocks may share a reset control. > The reset control API for shared resets will only assert such a reset > when the drivers for all hardware blocks agree. > The exclusive reset control API still allows to assert such a reset, but > that impacts all other hardware blocks sharing the reset. > > While the kernel doc comments clearly state that the API for shared > resets applies to reset controls which are shared between hardware > blocks, the exact meaning of exclusive resets is not documented. > Fix the semantic ambiguity with respect to exclusive access vs. > exclusive reset lines by: > 1. Clarifying that exclusive resets really are intended for use with > reset controls which are dedicated to a single hardware block, > 2. Ensuring that obtaining an exclusive reset control will fail if the > reset is shared by multiple hardware blocks, for both DT-based and > lookup-based reset controls. > > Signed-off-by: Geert Uytterhoeven > --- > Question from Philipp for the DT maintainers: > > "I'd still like to hear the device tree maintainers' opinion on > parsing the whole DT for "resets" phandle properties to find shared > resets like this." Mark, Rob: Ping? Thanks! Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds