On 12 September 2016 at 13:01, Jon Hunter <jonathanh@xxxxxxxxxx> wrote:
> It is possible that a device has more than one provider of PM domains
> and to support the removal of a PM domain by provider, it is necessary
> to store a reference to the provider in the PM domain structure.
> Therefore, store a reference to the firmware node handle in the PM
> domain structure and populate it when providers (only device-tree based
> providers are currently supported by PM domains) are registered.
>
> Please note that when removing PM domains, it is necessary to verify
> that the PM domain provider has been removed from the list of providers
> before the PM domain can be removed. To do this add another member to
> the PM domain structure that indicates if the provider is present and
> set this member accordingly when providers are added and removed.
>
> Initialise the 'provider' and 'has_provider' members of the
> generic_pm_domain structure when a PM domains is added by calling
> pm_genpd_init().
>
> Signed-off-by: Jon Hunter <jonathanh@xxxxxxxxxx>
Acked-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Kind regards
Uffe
> ---
> drivers/base/power/domain.c | 42 +++++++++++++++++++++++++++++++++++++-----
> include/linux/pm_domain.h | 2 ++
> 2 files changed, 39 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
> index 1bd8d412db06..d5135caa84db 100644
> --- a/drivers/base/power/domain.c
> +++ b/drivers/base/power/domain.c
> @@ -1306,6 +1306,8 @@ int pm_genpd_init(struct generic_pm_domain *genpd,
> genpd->device_count = 0;
> genpd->max_off_time_ns = -1;
> genpd->max_off_time_changed = true;
> + genpd->provider = NULL;
> + genpd->has_provider = false;
> genpd->domain.ops.runtime_suspend = genpd_runtime_suspend;
> genpd->domain.ops.runtime_resume = genpd_runtime_resume;
> genpd->domain.ops.prepare = pm_genpd_prepare;
> @@ -1491,6 +1493,11 @@ int of_genpd_add_provider_simple(struct device_node *np,
> if (pm_genpd_present(genpd))
> ret = genpd_add_provider(np, genpd_xlate_simple, genpd);
>
> + if (!ret) {
> + genpd->provider = &np->fwnode;
> + genpd->has_provider = true;
> + }
> +
> mutex_unlock(&gpd_list_lock);
>
> return ret;
> @@ -1506,7 +1513,7 @@ int of_genpd_add_provider_onecell(struct device_node *np,
> struct genpd_onecell_data *data)
> {
> unsigned int i;
> - int ret;
> + int ret = -EINVAL;
>
> if (!np || !data)
> return -EINVAL;
> @@ -1514,13 +1521,26 @@ int of_genpd_add_provider_onecell(struct device_node *np,
> mutex_lock(&gpd_list_lock);
>
> for (i = 0; i < data->num_domains; i++) {
> - if (!pm_genpd_present(data->domains[i])) {
> - mutex_unlock(&gpd_list_lock);
> - return -EINVAL;
> - }
> + if (!pm_genpd_present(data->domains[i]))
> + goto error;
> +
> + data->domains[i]->provider = &np->fwnode;
> + data->domains[i]->has_provider = true;
> }
>
> ret = genpd_add_provider(np, genpd_xlate_onecell, data);
> + if (ret < 0)
> + goto error;
> +
> + mutex_unlock(&gpd_list_lock);
> +
> + return 0;
> +
> +error:
> + while (i--) {
> + data->domains[i]->provider = NULL;
> + data->domains[i]->has_provider = false;
> + }
>
> mutex_unlock(&gpd_list_lock);
>
> @@ -1535,10 +1555,21 @@ EXPORT_SYMBOL_GPL(of_genpd_add_provider_onecell);
> void of_genpd_del_provider(struct device_node *np)
> {
> struct of_genpd_provider *cp;
> + struct generic_pm_domain *gpd;
>
> + mutex_lock(&gpd_list_lock);
> mutex_lock(&of_genpd_mutex);
> list_for_each_entry(cp, &of_genpd_providers, link) {
> if (cp->node == np) {
> + /*
> + * For each PM domain associated with the
> + * provider, set the 'has_provider' to false
> + * so that the PM domain can be safely removed.
> + */
> + list_for_each_entry(gpd, &gpd_list, gpd_list_node)
> + if (gpd->provider == &np->fwnode)
> + gpd->has_provider = false;
> +
> list_del(&cp->link);
> of_node_put(cp->node);
> kfree(cp);
> @@ -1546,6 +1577,7 @@ void of_genpd_del_provider(struct device_node *np)
> }
> }
> mutex_unlock(&of_genpd_mutex);
> + mutex_unlock(&gpd_list_lock);
> }
> EXPORT_SYMBOL_GPL(of_genpd_del_provider);
>
> diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
> index f103869db443..554f8915c691 100644
> --- a/include/linux/pm_domain.h
> +++ b/include/linux/pm_domain.h
> @@ -51,6 +51,8 @@ struct generic_pm_domain {
> struct mutex lock;
> struct dev_power_governor *gov;
> struct work_struct power_off_work;
> + struct fwnode_handle *provider; /* Identity of the domain provider */
> + bool has_provider;
> const char *name;
> atomic_t sd_count; /* Number of subdomains with power "on" */
> enum gpd_status status; /* Current state of the domain */
> --
> 2.1.4
>
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