From: Ulf Hansson <ulf.hansson@linaro.org>
Date: Mon, 27 May 2024 14:25:52 +0000 (+0200)
Subject: pmdomain: core: Don't hold the genpd-lock when calling dev_pm_domain_set()
X-Git-Tag: v6.12-rc1~154^2~39
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=b87eee38605c396f0e1fa435939960e5c6cd41d6;p=thirdparty%2Fkernel%2Flinux.git

pmdomain: core: Don't hold the genpd-lock when calling dev_pm_domain_set()

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>
Tested-by: Raghavendra Kakarla <quic_rkakarla@quicinc.com>  # qcm6490 with PREEMPT_RT set
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20240527142557.321610-3-ulf.hansson@linaro.org
---

diff --git a/drivers/pmdomain/core.c b/drivers/pmdomain/core.c
index 8c798a46ffec0..ef61486d41ee9 100644
--- a/drivers/pmdomain/core.c
+++ b/drivers/pmdomain/core.c
@@ -1800,7 +1800,6 @@ 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)
@@ -1809,6 +1808,7 @@ 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);
@@ -1865,12 +1865,13 @@ 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);