From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754351AbaKSNWc (ORCPT ); Wed, 19 Nov 2014 08:22:32 -0500 Received: from mail-wg0-f51.google.com ([74.125.82.51]:64866 "EHLO mail-wg0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752765AbaKSNWa (ORCPT ); Wed, 19 Nov 2014 08:22:30 -0500 From: Tomeu Vizoso To: linux-tegra@vger.kernel.org Cc: Javier Martinez Canillas , Tomeu Vizoso , "Rafael J. Wysocki" , Viresh Kumar , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] cpufreq: Ref the policy object sooner Date: Wed, 19 Nov 2014 14:21:31 +0100 Message-Id: <1416403291-7722-1-git-send-email-tomeu.vizoso@collabora.com> X-Mailer: git-send-email 1.9.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Do it before it's assigned to cpufreq_cpu_data, otherwise we can get this warning when a driver tries to get the cpu frequency during initialization: ------------[ cut here ]------------ WARNING: CPU: 1 PID: 64 at include/linux/kref.h:47 kobject_get+0x64/0x70() Modules linked in: CPU: 1 PID: 64 Comm: irq/77-tegra-ac Not tainted 3.18.0-rc4-next-20141114ccu-00050-g3eff942 #326 [] (unwind_backtrace) from [] (show_stack+0x10/0x14) [] (show_stack) from [] (dump_stack+0x98/0xd8) [] (dump_stack) from [] (warn_slowpath_common+0x84/0xb4) [] (warn_slowpath_common) from [] (warn_slowpath_null+0x1c/0x24) [] (warn_slowpath_null) from [] (kobject_get+0x64/0x70) [] (kobject_get) from [] (cpufreq_cpu_get+0x88/0xc8) [] (cpufreq_cpu_get) from [] (cpufreq_get+0xc/0x64) [] (cpufreq_get) from [] (actmon_thread_isr+0x134/0x198) [] (actmon_thread_isr) from [] (irq_thread_fn+0x1c/0x40) [] (irq_thread_fn) from [] (irq_thread+0x134/0x174) [] (irq_thread) from [] (kthread+0xdc/0xf4) [] (kthread) from [] (ret_from_fork+0x14/0x3c) ---[ end trace b7bd64a81b340c59 ]--- Signed-off-by: Tomeu Vizoso --- drivers/cpufreq/cpufreq.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 4473eba..954cb2f 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -898,12 +898,6 @@ static int cpufreq_add_dev_interface(struct cpufreq_policy *policy, struct freq_attr **drv_attr; int ret = 0; - /* prepare interface data */ - ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, - &dev->kobj, "cpufreq"); - if (ret) - return ret; - /* set up files for this cpu device */ drv_attr = cpufreq_driver->attr; while ((drv_attr) && (*drv_attr)) { @@ -1211,6 +1205,15 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) } down_write(&policy->rwsem); + + /* prepare interface data */ + ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, + &dev->kobj, "cpufreq"); + if (ret) { + pr_err("%s: failed to init policy->kobj: %d\n", __func__, ret); + goto err_init_policy_kobj; + } + write_lock_irqsave(&cpufreq_driver_lock, flags); for_each_cpu(j, policy->cpus) per_cpu(cpufreq_cpu_data, j) = policy; @@ -1301,6 +1304,7 @@ err_get_freq: per_cpu(cpufreq_cpu_data, j) = NULL; write_unlock_irqrestore(&cpufreq_driver_lock, flags); +err_init_policy_kobj: up_write(&policy->rwsem); if (cpufreq_driver->exit) -- 1.9.3