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[209.132.180.67]) by mx.google.com with ESMTP id p3si7318171pds.160.2015.07.01.23.25.08; Wed, 01 Jul 2015 23:25:09 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-pm-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752590AbbGBGZH (ORCPT + 11 others); Thu, 2 Jul 2015 02:25:07 -0400 Received: from mail-pa0-f53.google.com ([209.85.220.53]:33888 "EHLO mail-pa0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752351AbbGBGZG (ORCPT ); Thu, 2 Jul 2015 02:25:06 -0400 Received: by pabvl15 with SMTP id vl15so35335089pab.1 for ; Wed, 01 Jul 2015 23:25:05 -0700 (PDT) X-Received: by 10.70.17.66 with SMTP id m2mr63334165pdd.49.1435818305731; Wed, 01 Jul 2015 23:25:05 -0700 (PDT) Received: from localhost ([223.227.117.39]) by mx.google.com with ESMTPSA id pj6sm4336051pac.18.2015.07.01.23.25.01 (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Wed, 01 Jul 2015 23:25:04 -0700 (PDT) Date: Thu, 2 Jul 2015 11:54:55 +0530 From: Viresh Kumar To: Stephen Boyd Cc: Rafael Wysocki , rob.herring@linaro.org, nm@ti.com, linaro-kernel@lists.linaro.org, linux-pm@vger.kernel.org, arnd.bergmann@linaro.org, broonie@kernel.org, mike.turquette@linaro.org, Sudeep.Holla@arm.com, viswanath.puttagunta@linaro.org, l.stach@pengutronix.de, thomas.petazzoni@free-electrons.com, linux-arm-kernel@lists.infradead.org, ta.omasab@gmail.com, kesavan.abhilash@gmail.com, khilman@linaro.org, santosh.shilimkar@oracle.com Subject: Re: [PATCH 03/10] OPP: Allocate dev_opp from _add_device_opp() Message-ID: <20150702062455.GD31684@linux> References: <83bd3b9837b30bab62f41aed3dd2cdf52cc21688.1434369079.git.viresh.kumar@linaro.org> <55948DB0.8060500@codeaurora.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <55948DB0.8060500@codeaurora.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-pm-owner@vger.kernel.org Precedence: list List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Removed-Original-Auth: Dkim didn't pass. X-Original-Sender: viresh.kumar@linaro.org X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of patch+caf_=patchwork-forward=linaro.org@linaro.org designates 209.85.217.176 as permitted sender) smtp.mail=patch+caf_=patchwork-forward=linaro.org@linaro.org Mailing-list: list patchwork-forward@linaro.org; contact patchwork-forward+owners@linaro.org X-Google-Group-Id: 836684582541 List-Post: , List-Help: , List-Archive: List-Unsubscribe: , On 01-07-15, 18:02, Stephen Boyd wrote: > On 06/15/2015 04:57 AM, Viresh Kumar wrote: > > + * _add_device_opp() - Returns device OPP table > > Find device OPP table, or allocate a new one? Sure. > > static int _opp_add_dynamic(struct device *dev, unsigned long freq, > > long u_volt, bool dynamic) > > { > > - struct device_opp *dev_opp = NULL; > > - struct dev_pm_opp *opp, *new_opp; > > + struct device_opp *dev_opp; > > + struct dev_pm_opp *opp = NULL, *new_opp; > > Hm... > > /* Duplicate OPPs ? */ > > - if (new_opp->rate == opp->rate) { > > + if (opp && new_opp->rate == opp->rate) { > > Isn't opp always non-NULL at this point? Maybe this if statement should > be moved into the list_for_each_entry_rcu() loop. when the dev_opp was getting created for the first time, before this patch, we used to do a 'goto list_add'. And so control never reached here, but now we might find a empty list of OPPs and so 'opp' can be NULL here. Not sure about moving this to the loop, as we are already taking 'dev_opp_list_lock' in this routine. > > +remove_dev_opp: > > + _remove_device_opp(dev_opp); > > Doesn't this just return early because dev_opp has something in it? Hmm, it isn't required probably. ---------------------8<----------------------- Message-Id: From: Viresh Kumar Date: Fri, 12 Jun 2015 12:43:14 +0530 Subject: [PATCH] OPP: Allocate dev_opp from _add_device_opp() There is no need to complicate _opp_add_dynamic() with allocation of dev_opp as well. Allocate it from _add_device_opp() instead. Signed-off-by: Viresh Kumar --- drivers/base/power/opp.c | 35 ++++++++++++++++------------------- 1 file changed, 16 insertions(+), 19 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c index 7895fdd64192..f8df0ad3e822 100644 --- a/drivers/base/power/opp.c +++ b/drivers/base/power/opp.c @@ -408,11 +408,11 @@ struct dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev, EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor); /** - * _add_device_opp() - Allocate a new device OPP table + * _add_device_opp() - Find device OPP table or allocate a new one * @dev: device for which we do this operation * - * New device node which uses OPPs - used when multiple devices with OPP tables - * are maintained. + * It tries to find an existing table first, if it couldn't find one, it + * allocates a new OPP table and returns that. * * Return: valid device_opp pointer if success, else NULL. */ @@ -420,6 +420,11 @@ static struct device_opp *_add_device_opp(struct device *dev) { struct device_opp *dev_opp; + /* Check for existing list for 'dev' first */ + dev_opp = _find_device_opp(dev); + if (!IS_ERR(dev_opp)) + return dev_opp; + /* * Allocate a new device OPP table. In the infrequent case where a new * device is needed to be added, we pay this penalty. @@ -575,8 +580,8 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_remove); static int _opp_add_dynamic(struct device *dev, unsigned long freq, long u_volt, bool dynamic) { - struct device_opp *dev_opp = NULL; - struct dev_pm_opp *opp, *new_opp; + struct device_opp *dev_opp; + struct dev_pm_opp *opp = NULL, *new_opp; struct list_head *head; int ret; @@ -592,19 +597,11 @@ static int _opp_add_dynamic(struct device *dev, unsigned long freq, new_opp->rate = freq; new_opp->u_volt = u_volt; new_opp->available = true; - new_opp->dynamic = dynamic; - /* Check for existing list for 'dev' */ - dev_opp = _find_device_opp(dev); - if (IS_ERR(dev_opp)) { - dev_opp = _add_device_opp(dev); - if (!dev_opp) { - ret = -ENOMEM; - goto free_opp; - } - - head = &dev_opp->opp_list; - goto list_add; + dev_opp = _add_device_opp(dev); + if (!dev_opp) { + ret = -ENOMEM; + goto free_opp; } /* @@ -620,7 +617,7 @@ static int _opp_add_dynamic(struct device *dev, unsigned long freq, } /* Duplicate OPPs ? */ - if (new_opp->rate == opp->rate) { + if (opp && new_opp->rate == opp->rate) { ret = opp->available && new_opp->u_volt == opp->u_volt ? 0 : -EEXIST; @@ -630,7 +627,7 @@ static int _opp_add_dynamic(struct device *dev, unsigned long freq, goto free_opp; } -list_add: + new_opp->dynamic = dynamic; new_opp->dev_opp = dev_opp; list_add_rcu(&new_opp->node, head); mutex_unlock(&dev_opp_list_lock);