This is a note to let you know that I've just added the patch titled
pmdomain: core: Don't hold the genpd-lock when calling dev_pm_domain_set()
to the 6.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
pmdomain-core-don-t-hold-the-genpd-lock-when-calling.patch
and it can be found in the queue-6.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 98f8d5886c9ab96dab11b5ea593d58f59f70e3b6
Author: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Date: Mon May 27 16:25:52 2024 +0200
pmdomain: core: Don't hold the genpd-lock when calling dev_pm_domain_set()
[ Upstream commit b87eee38605c396f0e1fa435939960e5c6cd41d6 ]
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@xxxxxxxxxx>
Tested-by: Raghavendra Kakarla <quic_rkakarla@xxxxxxxxxxx> # qcm6490 with PREEMPT_RT set
Acked-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20240527142557.321610-3-ulf.hansson@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/pmdomain/core.c b/drivers/pmdomain/core.c
index 0ab6008e863e8..4134a8344d2da 100644
--- a/drivers/pmdomain/core.c
+++ b/drivers/pmdomain/core.c
@@ -1694,7 +1694,6 @@ 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)
@@ -1703,6 +1702,7 @@ 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);
@@ -1759,12 +1759,13 @@ 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);
