From patchwork Tue Mar 12 19:20:49 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ulf Hansson X-Patchwork-Id: 15305 Return-Path: X-Original-To: patchwork@peony.canonical.com Delivered-To: patchwork@peony.canonical.com Received: from fiordland.canonical.com (fiordland.canonical.com [91.189.94.145]) by peony.canonical.com (Postfix) with ESMTP id 9F8B123E2C for ; Tue, 12 Mar 2013 19:21:16 +0000 (UTC) Received: from mail-ve0-f178.google.com (mail-ve0-f178.google.com [209.85.128.178]) by fiordland.canonical.com (Postfix) with ESMTP id 4B687A18567 for ; Tue, 12 Mar 2013 19:21:16 +0000 (UTC) Received: by mail-ve0-f178.google.com with SMTP id db10so175038veb.9 for ; Tue, 12 Mar 2013 12:21:15 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=x-received:x-forwarded-to:x-forwarded-for:delivered-to:x-received :received-spf:from:to:cc:subject:date:message-id:x-mailer :in-reply-to:references:mime-version:content-type:x-gm-message-state; bh=YOAJbB0FfOxXbQYcJ6imI1GEZhhXANqx2x5KElwx3pc=; b=mxeh9Dd3UWHgwZFHMePEyamnUg4VonW5F+wDcIO4MARtPOAMw6EoxAq0JNxtrwkwvC WOUIS0X0uD/drooNXavPBnFw2xKcBpxakmqKS2mM4REQFCMyaiyzfu7TV25NJtvkYY/p KTz5a5h+AG+DtfKGWb9ar4lOcCo6y0VGSDGL5nb44wABlH6c7k8eP1WKWtjcRGDb0abX SfmtlncGitjqM4R9A0SxL6rLI00fO4DQvmNRMIfbq6BE6ZqroHiQIFjt4Ta4eiYhFTAG hp7e4l73kGpizs7MDB6FSunu5DH6fMW9gJ8vX337vSwiq9/8Wd8tX9wjbbAYKXuaUkmO Yitg== X-Received: by 10.52.88.237 with SMTP id bj13mr6089640vdb.75.1363116075805; Tue, 12 Mar 2013 12:21:15 -0700 (PDT) X-Forwarded-To: linaro-patchwork@canonical.com X-Forwarded-For: patch@linaro.org linaro-patchwork@canonical.com Delivered-To: patches@linaro.org Received: by 10.58.127.98 with SMTP id nf2csp144396veb; Tue, 12 Mar 2013 12:21:15 -0700 (PDT) X-Received: by 10.14.194.198 with SMTP id m46mr50729946een.8.1363116074784; Tue, 12 Mar 2013 12:21:14 -0700 (PDT) Received: from eu1sys200aog108.obsmtp.com (eu1sys200aog108.obsmtp.com [207.126.144.125]) by mx.google.com with SMTP id r44si37365101eeo.85.2013.03.12.12.21.09 (version=TLSv1 cipher=RC4-SHA bits=128/128); Tue, 12 Mar 2013 12:21:14 -0700 (PDT) Received-SPF: neutral (google.com: 207.126.144.125 is neither permitted nor denied by best guess record for domain of ulf.hansson@stericsson.com) client-ip=207.126.144.125; Authentication-Results: mx.google.com; spf=neutral (google.com: 207.126.144.125 is neither permitted nor denied by best guess record for domain of ulf.hansson@stericsson.com) smtp.mail=ulf.hansson@stericsson.com Received: from beta.dmz-ap.st.com ([138.198.100.35]) (using TLSv1) by eu1sys200aob108.postini.com ([207.126.147.11]) with SMTP ID DSNKUT+AJU1YR/Sw30oDpt+7nqynF0jRlxXN@postini.com; Tue, 12 Mar 2013 19:21:14 UTC Received: from zeta.dmz-ap.st.com (ns6.st.com [138.198.234.13]) by beta.dmz-ap.st.com (STMicroelectronics) with ESMTP id 45810A3; Tue, 12 Mar 2013 19:12:58 +0000 (GMT) Received: from relay2.stm.gmessaging.net (unknown [10.230.100.18]) by zeta.dmz-ap.st.com (STMicroelectronics) with ESMTP id CA96B563; Tue, 12 Mar 2013 19:21:05 +0000 (GMT) Received: from exdcvycastm004.EQ1STM.local (alteon-source-exch [10.230.100.61]) (using TLSv1 with cipher RC4-MD5 (128/128 bits)) (Client CN "exdcvycastm004", Issuer "exdcvycastm004" (not verified)) by relay2.stm.gmessaging.net (Postfix) with ESMTPS id C6972A8074; Tue, 12 Mar 2013 20:20:57 +0100 (CET) Received: from steludxu1397.stericsson.com (10.230.100.153) by smtp.stericsson.com (10.230.100.2) with Microsoft SMTP Server (TLS) id 8.3.83.0; Tue, 12 Mar 2013 20:21:04 +0100 From: Ulf Hansson To: , Mike Turquette Cc: Linus Walleij , Par-Olof Hakansson , Ulf Hansson Subject: [RESEND PATCH 2/3] clk: Improve errorhandling for clk_set_parent Date: Tue, 12 Mar 2013 20:20:49 +0100 Message-ID: <1363116050-3882-3-git-send-email-ulf.hansson@stericsson.com> X-Mailer: git-send-email 1.7.10 In-Reply-To: <1363116050-3882-1-git-send-email-ulf.hansson@stericsson.com> References: <1363116050-3882-1-git-send-email-ulf.hansson@stericsson.com> MIME-Version: 1.0 X-Gm-Message-State: ALoCoQl8Ie+QRF9qzR5unl9R4cVQghokNrkIYTXIQR0eOxB8J70uDt1Fl8VXUSojPEa1l5vpziaP From: Ulf Hansson By verifying all the needed static information before doing the clk notifications, we minimize number of unwanted rollback notifications with ABORT_RATE_CHANGE message to occur. Additionally make sure the parent are valid pointer before using it. Signed-off-by: Ulf Hansson --- drivers/clk/clk.c | 48 +++++++++++++++++++++++++++++------------------- 1 file changed, 29 insertions(+), 19 deletions(-) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 2e10cc1..a61cf6d 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -1227,15 +1227,10 @@ static void clk_reparent(struct clk *clk, struct clk *new_parent) clk->parent = new_parent; } -static int __clk_set_parent(struct clk *clk, struct clk *parent) +static u8 clk_fetch_parent_index(struct clk *clk, struct clk *parent) { - struct clk *old_parent; - unsigned long flags; - int ret = -EINVAL; u8 i; - old_parent = clk->parent; - if (!clk->parents) clk->parents = kzalloc((sizeof(struct clk*) * clk->num_parents), GFP_KERNEL); @@ -1255,11 +1250,14 @@ static int __clk_set_parent(struct clk *clk, struct clk *parent) } } - if (i == clk->num_parents) { - pr_debug("%s: clock %s is not a possible parent of clock %s\n", - __func__, parent->name, clk->name); - goto out; - } + return i; +} + +static int __clk_set_parent(struct clk *clk, struct clk *parent, u8 p_index) +{ + unsigned long flags; + int ret; + struct clk *old_parent = clk->parent; /* migrate prepare and enable */ if (clk->prepare_count) @@ -1272,7 +1270,7 @@ static int __clk_set_parent(struct clk *clk, struct clk *parent) spin_unlock_irqrestore(&enable_lock, flags); /* change clock input source */ - ret = clk->ops->set_parent(clk->hw, i); + ret = clk->ops->set_parent(clk->hw, p_index); /* clean up old prepare and enable */ spin_lock_irqsave(&enable_lock, flags); @@ -1283,7 +1281,6 @@ static int __clk_set_parent(struct clk *clk, struct clk *parent) if (clk->prepare_count) __clk_unprepare(old_parent); -out: return ret; } @@ -1302,8 +1299,9 @@ out: int clk_set_parent(struct clk *clk, struct clk *parent) { int ret = 0; + u8 p_index; - if (!clk || !clk->ops) + if (!clk || !clk->ops || !parent) return -EINVAL; if (!clk->ops->set_parent) @@ -1315,6 +1313,21 @@ int clk_set_parent(struct clk *clk, struct clk *parent) if (clk->parent == parent) goto out; + /* check that we are allowed to re-parent if the clock is in use */ + if ((clk->flags & CLK_SET_PARENT_GATE) && clk->prepare_count) { + ret = -EBUSY; + goto out; + } + + /* try finding the new parent index */ + p_index = clk_fetch_parent_index(clk, parent); + if (p_index == clk->num_parents) { + pr_debug("%s: clock %s is not a possible parent of clock %s\n", + __func__, parent->name, clk->name); + ret = -EINVAL; + goto out; + } + /* propagate PRE_RATE_CHANGE notifications */ if (clk->notifier_count) ret = __clk_speculate_rates(clk, parent->rate); @@ -1323,11 +1336,8 @@ int clk_set_parent(struct clk *clk, struct clk *parent) if (ret == NOTIFY_STOP) goto out; - /* only re-parent if the clock is not in use */ - if ((clk->flags & CLK_SET_PARENT_GATE) && clk->prepare_count) - ret = -EBUSY; - else - ret = __clk_set_parent(clk, parent); + /* do the re-parent */ + ret = __clk_set_parent(clk, parent, p_index); /* propagate ABORT_RATE_CHANGE if .set_parent failed */ if (ret) {