Re: [PATCH 4/4] PM / Domains: Allow to attach a CPU via genpd_dev_pm_attach_by_id|name()

Viresh Kumar
2019-04-25T09:47:58Z

On 25-04-19, 11:04, Ulf Hansson wrote:
> Attaching a device via genpd_dev_pm_attach_by_id|name() makes genpd to
> allocate a virtual device that it attaches instead. This leads to a problem
> in case the base device belongs to a CPU. More precisely, it means
> genpd_get_cpu() compares against the virtual device, thus it fails to find
> a matching CPU device.
>
> Address this limitation, by passing the base device to genpd_get_cpu()
> rather than the virtual device. Moreover, to deal with detach correctly
> from genpd_remove_device(), let's store the CPU number in the struct
> generic_pm_domain_data, as to be able to clear the corresponding bit in the
> cpumask for the genpd.
>
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> ---
> drivers/base/power/domain.c | 20 ++++++++++----------
> include/linux/pm_domain.h | 1 +
> 2 files changed, 11 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
> index da1c99178943..3d899e8abd58 100644
> --- a/drivers/base/power/domain.c
> +++ b/drivers/base/power/domain.c
> @@ -1499,10 +1499,11 @@ static int genpd_get_cpu(struct generic_pm_domain *genpd, struct device *dev)
> return -1;
> }
>
> -static int genpd_add_device(struct generic_pm_domain *genpd, struct device *dev)
> +static int genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
> + struct device *base_dev)
> {
> struct generic_pm_domain_data *gpd_data;
> - int ret, cpu;
> + int ret;
>
> dev_dbg(dev, "%s()\n", __func__);
>
> @@ -1513,7 +1514,7 @@ static int genpd_add_device(struct generic_pm_domain *genpd, struct device *dev)
> if (IS_ERR(gpd_data))
> return PTR_ERR(gpd_data);
>
> - cpu = genpd_get_cpu(genpd, dev);
> + gpd_data->cpu = genpd_get_cpu(genpd, base_dev);
>
> ret = genpd->attach_dev ? genpd->attach_dev(genpd, dev) : 0;
> if (ret)
> @@ -1521,7 +1522,7 @@ static int genpd_add_device(struct generic_pm_domain *genpd, struct device *dev)
>
> genpd_lock(genpd);
>
> - genpd_set_cpumask(genpd, cpu);
> + genpd_set_cpumask(genpd, gpd_data->cpu);
> dev_pm_domain_set(dev, &genpd->domain);
>
> genpd->device_count++;
> @@ -1549,7 +1550,7 @@ int pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev)
> int ret;
>
> mutex_lock(&gpd_list_lock);
> - ret = genpd_add_device(genpd, dev);
> + ret = genpd_add_device(genpd, dev, dev);
> mutex_unlock(&gpd_list_lock);
>
> return ret;
> @@ -1561,14 +1562,13 @@ static int genpd_remove_device(struct generic_pm_domain *genpd,
> {
> struct generic_pm_domain_data *gpd_data;
> struct pm_domain_data *pdd;
> - int cpu, ret = 0;
> + int ret = 0;
>
> dev_dbg(dev, "%s()\n", __func__);
>
> pdd = dev->power.subsys_data->domain_data;
> gpd_data = to_gpd_data(pdd);
> dev_pm_qos_remove_notifier(dev, &gpd_data->nb);
> - cpu = genpd_get_cpu(genpd, dev);
>
> genpd_lock(genpd);
>
> @@ -1580,7 +1580,7 @@ static int genpd_remove_device(struct generic_pm_domain *genpd,
> genpd->device_count--;
> genpd->max_off_time_changed = true;
>
> - genpd_clear_cpumask(genpd, cpu);
> + genpd_clear_cpumask(genpd, gpd_data->cpu);
> dev_pm_domain_set(dev, NULL);
>
> list_del_init(&pdd->list_node);
> @@ -2256,7 +2256,7 @@ int of_genpd_add_device(struct of_phandle_args *genpdspec, struct device *dev)
> goto out;
> }
>
> - ret = genpd_add_device(genpd, dev);
> + ret = genpd_add_device(genpd, dev, dev);
>
> out:
> mutex_unlock(&gpd_list_lock);
> @@ -2426,7 +2426,7 @@ static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev,
>
> dev_dbg(dev, "adding to PM domain %s\n", pd->name);
>
> - ret = genpd_add_device(pd, dev);
> + ret = genpd_add_device(pd, dev, base_dev);
> mutex_unlock(&gpd_list_lock);
>
> if (ret < 0) {
> diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
> index bc82e74560ee..0e8e356bed6a 100644
> --- a/include/linux/pm_domain.h
> +++ b/include/linux/pm_domain.h
> @@ -175,6 +175,7 @@ struct generic_pm_domain_data {
> struct pm_domain_data base;
> struct gpd_timing_data td;
> struct notifier_block nb;
> + int cpu;
> unsigned int performance_state;
> void *data;
> };

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>

--
viresh