From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Boyd Subject: Re: [PATCH 12/12] PM / OPP: Update Documentation to remove RCU specific bits Date: Mon, 9 Jan 2017 14:39:37 -0800 Message-ID: <20170109223937.GR17126@codeaurora.org> References: <164ad6c0c6a5200eae99a7ac23554f33542f465b.1481106919.git.viresh.kumar@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from smtp.codeaurora.org ([198.145.29.96]:36512 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754245AbdAIWjj (ORCPT ); Mon, 9 Jan 2017 17:39:39 -0500 Content-Disposition: inline In-Reply-To: <164ad6c0c6a5200eae99a7ac23554f33542f465b.1481106919.git.viresh.kumar@linaro.org> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Viresh Kumar Cc: Rafael Wysocki , Viresh Kumar , Nishanth Menon , Len Brown , Pavel Machek , linaro-kernel@lists.linaro.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Vincent Guittot On 12/07, Viresh Kumar wrote: > @@ -137,15 +121,18 @@ functions return the matching pointer representing the opp if a match is > found, else returns error. These errors are expected to be handled by standard > error checks such as IS_ERR() and appropriate actions taken by the caller. > > +Callers of these functions shall call dev_pm_opp_put() after they have used the > +OPP. Otherwise the memory for the OPP will never get freed and result in > +memleak. > + > dev_pm_opp_find_freq_exact - Search for an OPP based on an *exact* frequency and > availability. This function is especially useful to enable an OPP which > is not available by default. > Example: In a case when SoC framework detects a situation where a > higher frequency could be made available, it can use this function to > find the OPP prior to call the dev_pm_opp_enable to actually make it available. > - rcu_read_lock(); > opp = dev_pm_opp_find_freq_exact(dev, 1000000000, false); > - rcu_read_unlock(); > + dev_pm_opp_put(opp); > /* dont operate on the pointer.. just do a sanity check.. */ > if (IS_ERR(opp)) { > pr_err("frequency not disabled!\n"); > @@ -163,9 +150,8 @@ dev_pm_opp_find_freq_floor - Search for an available OPP which is *at most* the > frequency. > Example: To find the highest opp for a device: > freq = ULONG_MAX; > - rcu_read_lock(); > dev_pm_opp_find_freq_floor(dev, &freq); > - rcu_read_unlock(); > + dev_pm_opp_put(opp); opp doesn't exist in the scope here. Missing an assignment during the dev_pm_opp_find_freq_floor() call? -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project