On Mon, 2015-11-30 at 15:00 +0530, Viresh Kumar wrote: > On 30-11-15, 17:26, dawei chien wrote: > > On Mon, 2015-11-30 at 11:08 +0530, Viresh Kumar wrote: > > > On 27-11-15, 17:32, Dawei Chien wrote: > > > > MT8173 cpufreq driver use of_cpufreq_power_cooling_register registering > > > > cooling devices with dynamic power coefficient. > > > > > > > > Signed-off-by: Dawei Chien <dawei.chien@xxxxxxxxxxxx> > > > > --- > > > > This patch is base on patchset: > > > > https://lkml.org/lkml/2015/11/17/251 > > > > --- > > > > drivers/cpufreq/mt8173-cpufreq.c | 28 ++++++++++++++++++++-------- > > > > 1 file changed, 20 insertions(+), 8 deletions(-) > > > > > > > > diff --git a/drivers/cpufreq/mt8173-cpufreq.c b/drivers/cpufreq/mt8173-cpufreq.c > > > > index 83001dc..4d39468 100644 > > > > --- a/drivers/cpufreq/mt8173-cpufreq.c > > > > +++ b/drivers/cpufreq/mt8173-cpufreq.c > > > > @@ -263,24 +263,34 @@ static int mtk_cpufreq_set_target(struct cpufreq_policy *policy, > > > > return 0; > > > > } > > > > > > > > +#define DYNAMIC_POWER "dynamic-power-coefficient" > > > > + > > > > static void mtk_cpufreq_ready(struct cpufreq_policy *policy) > > > > { > > > > struct mtk_cpu_dvfs_info *info = policy->driver_data; > > > > struct device_node *np = of_node_get(info->cpu_dev->of_node); > > > > + u32 capacitance; > > > > > > > > if (WARN_ON(!np)) > > > > return; > > > > > > > > if (of_find_property(np, "#cooling-cells", NULL)) { > > > > - info->cdev = of_cpufreq_cooling_register(np, > > > > - policy->related_cpus); > > > > + if (!info->cdev) { > > > > > > Why will info->cdev be non-NULL here ? > > > > This is a error-checking to avoid user or any script by command line hotplug CPU > > more than two times, we don't need to register cooling device on this case. > > Why? As far as I know, user or shell script has the right for using command online/offline cpu. Either user by console or shell script could make cpu2 online even cpu2 already onlined. That could cause of_cpufreq_cooling_register execute many times for the same cooling device. "echo 1 > /sys/devices/system/cpu/cpu2/online" With above hotplug command, mtk_cpufreq_ready will register cooling device again as well, but fail since the cooling device already created, so we might need not register cooling device again on this case. > > I will remove it if you don't agree it. > > No, my agreeing or not doesn't matter. If what you are doing is useful > (and I am not able to understand it), then you should make me > understand that and don't change your code. > > But, I really do not get the reasoning behind the logic. Please > elaborate that step by step. Please refer to above explaining, thank you. > > > > @@ -460,7 +470,9 @@ static int mtk_cpufreq_exit(struct cpufreq_policy *policy) > > > > { > > > > struct mtk_cpu_dvfs_info *info = policy->driver_data; > > > > > > > > - cpufreq_cooling_unregister(info->cdev); > > > > + if (info->cdev) > > > > + cpufreq_cooling_unregister(info->cdev); > > > > + > > > > > > Why do you need to update this? > > > > This is a error-checking to avoid user or any script by command line > > unplug CPU more than two times, we don't need to unregister cooling > > device on this case. > > > > I will remove it if you don't agree it. > > Same here. Please refer to the same reason as above. thank you. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
