Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756750Ab2J3IxI (ORCPT ); Tue, 30 Oct 2012 04:53:08 -0400 Received: from mail-ie0-f174.google.com ([209.85.223.174]:63398 "EHLO mail-ie0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756239Ab2J3IxE (ORCPT ); Tue, 30 Oct 2012 04:53:04 -0400 MIME-Version: 1.0 In-Reply-To: References: <50898F97.3000202@gmail.com> <1351235345-13050-1-git-send-email-hongbo.zhang@linaro.com> Date: Tue, 30 Oct 2012 09:53:02 +0100 Message-ID: Subject: Re: [PATCH V2 4/6] Thermal: Remove the cooling_cpufreq_list. From: Hongbo Zhang To: Amit Kachhap Cc: linaro-dev@lists.linaro.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, STEricsson_nomadik_linux@list.st.com, kernel@igloocommunity.org, linaro-kernel@lists.linaro.org, "hongbo.zhang" , patches@linaro.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 9503 Lines: 238 On 30 October 2012 09:03, Amit Kachhap wrote: > On 26 October 2012 12:39, hongbo.zhang wrote: >> From: "hongbo.zhang" >> >> Problem of using this list is that the cpufreq_get_max_state callback will be >> called when register cooling device by thermal_cooling_device_register, but >> this list isn't ready at this moment. What's more, there is no need to maintain >> such a list, we can get cpufreq_cooling_device instance by the private >> thermal_cooling_device.devdata. > > Hi, > > Removing this list seems fine as most of frequency checks are moved > inside generic thermal layer. > Some minor review comments below, > > Reviewed-by: Amit Daniel Kachhap Thanks. >> >> Signed-off-by: hongbo.zhang >> --- >> drivers/thermal/cpu_cooling.c | 91 +++++++++---------------------------------- >> 1 file changed, 19 insertions(+), 72 deletions(-) >> >> diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c >> index 415b041..2ffd12c 100644 >> --- a/drivers/thermal/cpu_cooling.c >> +++ b/drivers/thermal/cpu_cooling.c >> @@ -58,8 +58,9 @@ struct cpufreq_cooling_device { >> }; >> static LIST_HEAD(cooling_cpufreq_list); >> static DEFINE_IDR(cpufreq_idr); >> +static DEFINE_MUTEX(cooling_cpufreq_lock); >> >> -static struct mutex cooling_cpufreq_lock; >> +static unsigned int cpufreq_dev_count; >> >> /* notify_table passes value to the CPUFREQ_ADJUST callback function. */ >> #define NOTIFY_INVALID NULL >> @@ -240,28 +241,18 @@ static int cpufreq_thermal_notifier(struct notifier_block *nb, >> static int cpufreq_get_max_state(struct thermal_cooling_device *cdev, >> unsigned long *state) >> { >> - int ret = -EINVAL, i = 0; >> - struct cpufreq_cooling_device *cpufreq_device; >> - struct cpumask *maskPtr; >> + struct cpufreq_cooling_device *cpufreq_device = cdev->devdata; > check cdev is not null. >> + struct cpumask *maskPtr = &cpufreq_device->allowed_cpus; >> unsigned int cpu; >> struct cpufreq_frequency_table *table; >> unsigned long count = 0; >> + int i = 0; >> >> - mutex_lock(&cooling_cpufreq_lock); >> - list_for_each_entry(cpufreq_device, &cooling_cpufreq_list, node) { >> - if (cpufreq_device && cpufreq_device->cool_dev == cdev) >> - break; >> - } >> - if (cpufreq_device == NULL) >> - goto return_get_max_state; >> - >> - maskPtr = &cpufreq_device->allowed_cpus; >> cpu = cpumask_any(maskPtr); >> table = cpufreq_frequency_get_table(cpu); >> if (!table) { >> *state = 0; >> - ret = 0; >> - goto return_get_max_state; >> + return 0; >> } >> >> for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) { >> @@ -272,12 +263,10 @@ static int cpufreq_get_max_state(struct thermal_cooling_device *cdev, >> >> if (count > 0) { >> *state = --count; >> - ret = 0; >> + return 0; >> } >> >> -return_get_max_state: >> - mutex_unlock(&cooling_cpufreq_lock); >> - return ret; >> + return -EINVAL; >> } >> >> /** >> @@ -288,20 +277,10 @@ return_get_max_state: >> static int cpufreq_get_cur_state(struct thermal_cooling_device *cdev, >> unsigned long *state) >> { >> - int ret = -EINVAL; >> - struct cpufreq_cooling_device *cpufreq_device; >> + struct cpufreq_cooling_device *cpufreq_device = cdev->devdata; >> >> - mutex_lock(&cooling_cpufreq_lock); >> - list_for_each_entry(cpufreq_device, &cooling_cpufreq_list, node) { >> - if (cpufreq_device && cpufreq_device->cool_dev == cdev) { >> - *state = cpufreq_device->cpufreq_state; >> - ret = 0; >> - break; >> - } >> - } >> - mutex_unlock(&cooling_cpufreq_lock); >> - >> - return ret; >> + *state = cpufreq_device->cpufreq_state; >> + return 0; >> } >> >> /** >> @@ -312,22 +291,9 @@ static int cpufreq_get_cur_state(struct thermal_cooling_device *cdev, >> static int cpufreq_set_cur_state(struct thermal_cooling_device *cdev, >> unsigned long state) >> { >> - int ret = -EINVAL; >> - struct cpufreq_cooling_device *cpufreq_device; >> + struct cpufreq_cooling_device *cpufreq_device = cdev->devdata; > check cdev is not null Such values are used in all the three static cpufreq_***_state callback functions, when these functions are called, cdev->devdata should have been set in the registration function, and cannot be null, no body can call these function before registration, so I think there is no need to add such a check here. >> >> - mutex_lock(&cooling_cpufreq_lock); >> - list_for_each_entry(cpufreq_device, &cooling_cpufreq_list, node) { >> - if (cpufreq_device && cpufreq_device->cool_dev == cdev) { >> - ret = 0; >> - break; >> - } >> - } >> - if (!ret) >> - ret = cpufreq_apply_cooling(cpufreq_device, state); >> - >> - mutex_unlock(&cooling_cpufreq_lock); >> - >> - return ret; >> + return cpufreq_apply_cooling(cpufreq_device, state); >> } >> >> /* Bind cpufreq callbacks to thermal cooling device ops */ >> @@ -351,7 +317,7 @@ struct thermal_cooling_device *cpufreq_cooling_register( >> { >> struct thermal_cooling_device *cool_dev; >> struct cpufreq_cooling_device *cpufreq_dev = NULL; >> - unsigned int cpufreq_dev_count = 0, min = 0, max = 0; >> + unsigned int min = 0, max = 0; >> char dev_name[THERMAL_NAME_LENGTH]; >> int ret = 0, i; >> struct cpufreq_policy policy; >> @@ -360,9 +326,6 @@ struct thermal_cooling_device *cpufreq_cooling_register( >> if (!cpufreq_frequency_get_table(cpumask_any(clip_cpus))) >> return ERR_PTR(-EPROBE_DEFER); >> >> - list_for_each_entry(cpufreq_dev, &cooling_cpufreq_list, node) >> - cpufreq_dev_count++; >> - >> /*Verify that all the clip cpus have same freq_min, freq_max limit*/ >> for_each_cpu(i, clip_cpus) { >> /*continue if cpufreq policy not found and not return error*/ >> @@ -384,9 +347,6 @@ struct thermal_cooling_device *cpufreq_cooling_register( >> >> cpumask_copy(&cpufreq_dev->allowed_cpus, clip_cpus); >> >> - if (cpufreq_dev_count == 0) >> - mutex_init(&cooling_cpufreq_lock); >> - >> ret = get_idr(&cpufreq_idr, &cpufreq_dev->id); >> if (ret) { >> kfree(cpufreq_dev); >> @@ -405,12 +365,12 @@ struct thermal_cooling_device *cpufreq_cooling_register( >> cpufreq_dev->cool_dev = cool_dev; >> cpufreq_dev->cpufreq_state = 0; >> mutex_lock(&cooling_cpufreq_lock); >> - list_add_tail(&cpufreq_dev->node, &cooling_cpufreq_list); >> >> /* Register the notifier for first cpufreq cooling device */ >> if (cpufreq_dev_count == 0) >> cpufreq_register_notifier(&thermal_cpufreq_notifier_block, >> CPUFREQ_POLICY_NOTIFIER); >> + cpufreq_dev_count++; >> >> mutex_unlock(&cooling_cpufreq_lock); >> return cool_dev; >> @@ -423,33 +383,20 @@ EXPORT_SYMBOL(cpufreq_cooling_register); >> */ >> void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev) >> { >> - struct cpufreq_cooling_device *cpufreq_dev = NULL; >> - unsigned int cpufreq_dev_count = 0; >> + struct cpufreq_cooling_device *cpufreq_dev = cdev->devdata; >> >> mutex_lock(&cooling_cpufreq_lock); >> - list_for_each_entry(cpufreq_dev, &cooling_cpufreq_list, node) { >> - if (cpufreq_dev && cpufreq_dev->cool_dev == cdev) >> - break; >> - cpufreq_dev_count++; >> - } >> - >> - if (!cpufreq_dev || cpufreq_dev->cool_dev != cdev) { >> - mutex_unlock(&cooling_cpufreq_lock); >> - return; >> - } >> - >> - list_del(&cpufreq_dev->node); >> + cpufreq_dev_count--; >> >> /* Unregister the notifier for the last cpufreq cooling device */ >> - if (cpufreq_dev_count == 1) { >> + if (cpufreq_dev_count == 0) { >> cpufreq_unregister_notifier(&thermal_cpufreq_notifier_block, >> CPUFREQ_POLICY_NOTIFIER); >> } >> mutex_unlock(&cooling_cpufreq_lock); >> + >> thermal_cooling_device_unregister(cpufreq_dev->cool_dev); >> release_idr(&cpufreq_idr, cpufreq_dev->id); >> - if (cpufreq_dev_count == 1) >> - mutex_destroy(&cooling_cpufreq_lock); >> kfree(cpufreq_dev); >> } >> EXPORT_SYMBOL(cpufreq_cooling_unregister); >> -- >> 1.7.11.3 >> >> >> _______________________________________________ >> linaro-dev mailing list >> linaro-dev@lists.linaro.org >> http://lists.linaro.org/mailman/listinfo/linaro-dev -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/