[PATCH v2 2/7] pmdomain: core: Don't hold the genpd-lock when calling dev_pm_domain_set()

Ulf Hansson
2024-05-27T14:26:12Z

There is no need to hold the genpd-lock, while assigning the
dev->pm_domain. In fact, it becomes a problem on a PREEMPT_RT based
configuration as the genpd-lock may be a raw spinlock, while the lock
acquired through the call to dev_pm_domain_set() is a regular spinlock.

To fix the problem, let's simply move the calls to dev_pm_domain_set()
outside the genpd-lock.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---
Changes in v2:
- None.

---
drivers/pmdomain/core.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/pmdomain/core.c b/drivers/pmdomain/core.c
index 072e6bdb6ee6..454fccc38df1 100644
--- a/drivers/pmdomain/core.c
+++ b/drivers/pmdomain/core.c
@@ -1736,7 +1736,6 @@ static int genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
genpd_lock(genpd);

genpd_set_cpumask(genpd, gpd_data->cpu);
- dev_pm_domain_set(dev, &genpd->domain);

genpd->device_count++;
if (gd)
@@ -1745,6 +1744,7 @@ static int genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
list_add_tail(&gpd_data->base.list_node, &genpd->dev_list);

genpd_unlock(genpd);
+ dev_pm_domain_set(dev, &genpd->domain);
out:
if (ret)
genpd_free_dev_data(dev, gpd_data);
@@ -1801,12 +1801,13 @@ static int genpd_remove_device(struct generic_pm_domain *genpd,
genpd->gd->max_off_time_changed = true;

genpd_clear_cpumask(genpd, gpd_data->cpu);
- dev_pm_domain_set(dev, NULL);

list_del_init(&pdd->list_node);

genpd_unlock(genpd);

+ dev_pm_domain_set(dev, NULL);
+
if (genpd->detach_dev)
genpd->detach_dev(genpd, dev);

--
2.34.1