From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754305AbcGVQVz (ORCPT ); Fri, 22 Jul 2016 12:21:55 -0400 Received: from mail-pa0-f45.google.com ([209.85.220.45]:34101 "EHLO mail-pa0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752184AbcGVQVx (ORCPT ); Fri, 22 Jul 2016 12:21:53 -0400 Date: Fri, 22 Jul 2016 09:21:51 -0700 From: Viresh Kumar To: Jisheng Zhang Cc: vireshk@kernel.org, nm@ti.com, sboyd@codeaurora.org, rjw@rjwysocki.net, gregkh@linuxfoundation.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH] PM / OPP: optimize dev_pm_opp_set_rate() a bit Message-ID: <20160722162151.GT3122@ubuntu> References: <1469191370-1285-1-git-send-email-jszhang@marvell.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1469191370-1285-1-git-send-email-jszhang@marvell.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 22-07-16, 20:42, Jisheng Zhang wrote: > static int _set_opp_voltage(struct device *dev, struct regulator *reg, > unsigned long u_volt, unsigned long u_volt_min, > unsigned long u_volt_max) > @@ -586,9 +565,24 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq) > return -EINVAL; > } > > - clk = _get_opp_clk(dev); > - if (IS_ERR(clk)) > + rcu_read_lock(); > + > + opp_table = _find_opp_table(dev); > + if (IS_ERR(opp_table)) { > + dev_err(dev, "%s: device opp doesn't exist\n", __func__); > + rcu_read_unlock(); > + return PTR_ERR(opp_table); > + } > + > + clk = opp_table->clk; > + if (IS_ERR(clk)) { > + dev_err(dev, "%s: No clock available for the device\n", > + __func__); > + rcu_read_unlock(); > return PTR_ERR(clk); > + } > + > + rcu_read_unlock(); It is not _safe_ to use opp_table pointer after the rcu_read_unlock() here. -- viresh