From patchwork Sat Jan 31 01:31:58 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stephen Boyd X-Patchwork-Id: 5753801 Return-Path: X-Original-To: patchwork-linux-omap@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id AB8809F336 for ; Sat, 31 Jan 2015 01:32:36 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id DB8942027D for ; Sat, 31 Jan 2015 01:32:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0869C200D6 for ; Sat, 31 Jan 2015 01:32:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761689AbbAaBcG (ORCPT ); Fri, 30 Jan 2015 20:32:06 -0500 Received: from smtp.codeaurora.org ([198.145.11.231]:56458 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761350AbbAaBcB (ORCPT ); Fri, 30 Jan 2015 20:32:01 -0500 Received: from smtp.codeaurora.org (localhost [127.0.0.1]) by smtp.codeaurora.org (Postfix) with ESMTP id 0669F1406A2; Sat, 31 Jan 2015 01:32:00 +0000 (UTC) Received: by smtp.codeaurora.org (Postfix, from userid 486) id E69721406B2; Sat, 31 Jan 2015 01:31:59 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 Received: from localhost (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) (Authenticated sender: sboyd@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id 5DEED1406A2; Sat, 31 Jan 2015 01:31:59 +0000 (UTC) Date: Fri, 30 Jan 2015 17:31:58 -0800 From: Stephen Boyd To: Geert Uytterhoeven , Tomeu Vizoso , Mike Turquette Cc: Linux MIPS Mailing List , "linux-doc@vger.kernel.org" , Tony Lindgren , Chao Xie , Haojian Zhuang , Boris Brezillon , Russell King , Jonathan Corbet , Emilio L??pez , Linux-sh list , Alex Elder , Zhangfei Gao , Bintian Wang , Matt Porter , "linux-omap@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , Ralf Baechle , Tero Kristo , Manuel Lauss , Maxime Ripard , Javier Martinez Canillas Subject: Re: [PATCH v13 4/6] clk: Add rate constraints to clocks Message-ID: <20150131013158.GA4323@codeaurora.org> References: <1422011024-32283-1-git-send-email-tomeu.vizoso@collabora.com> <1422011024-32283-5-git-send-email-tomeu.vizoso@collabora.com> <54CA8662.7040008@codeaurora.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <54CA8662.7040008@codeaurora.org> User-Agent: Mutt/1.5.21 (2010-09-15) X-Virus-Scanned: ClamAV using ClamSMTP Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP On 01/29, Stephen Boyd wrote: > On 01/29/15 05:31, Geert Uytterhoeven wrote: > > Hi Tomeu, Mike, > > > > On Fri, Jan 23, 2015 at 12:03 PM, Tomeu Vizoso > > wrote: > >> --- a/drivers/clk/clk.c > >> +++ b/drivers/clk/clk.c > >> @@ -2391,25 +2543,24 @@ int __clk_get(struct clk *clk) > >> return 1; > >> } > >> > >> -static void clk_core_put(struct clk_core *core) > >> +void __clk_put(struct clk *clk) > >> { > >> struct module *owner; > >> > >> - owner = core->owner; > >> + if (!clk || WARN_ON_ONCE(IS_ERR(clk))) > >> + return; > >> > >> clk_prepare_lock(); > >> - kref_put(&core->ref, __clk_release); > >> + > >> + hlist_del(&clk->child_node); > >> + clk_core_set_rate_nolock(clk->core, clk->core->req_rate); > > At this point, clk->core->req_rate is still zero, causing > > cpg_div6_clock_round_rate() to be called with a zero "rate" parameter, > > e.g. on r8a7791: > > Hmm.. I wonder if we should assign core->req_rate to be the same as > core->rate during __clk_init()? That would make this call to > clk_core_set_rate_nolock() a nop in this case. > Here's a patch to do this ---8<---- From: Stephen Boyd Subject: [PATCH] clk: Assign a requested rate by default We need to assign a requested rate here so that we avoid requesting a rate of 0 on clocks when we remove clock consumers. Signed-off-by: Stephen Boyd Reviewed-by: Tomeu Vizoso --- drivers/clk/clk.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index a29daf9edea4..8416ed1c40be 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -2142,6 +2142,7 @@ int __clk_init(struct device *dev, struct clk *clk_user) struct clk_core *orphan; struct hlist_node *tmp2; struct clk_core *clk; + unsigned long rate; if (!clk_user) return -EINVAL; @@ -2266,12 +2267,13 @@ int __clk_init(struct device *dev, struct clk *clk_user) * then rate is set to zero. */ if (clk->ops->recalc_rate) - clk->rate = clk->ops->recalc_rate(clk->hw, + rate = clk->ops->recalc_rate(clk->hw, clk_core_get_rate_nolock(clk->parent)); else if (clk->parent) - clk->rate = clk->parent->rate; + rate = clk->parent->rate; else - clk->rate = 0; + rate = 0; + clk->rate = clk->req_rate = rate; /* * walk the list of orphan clocks and reparent any that are children of