summaryrefslogtreecommitdiffstats
path: root/drivers
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2022-07-08 13:01:04 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2022-07-08 13:01:04 -0700
commit3784fad934c5bd68551f0af4252821697957a72a (patch)
tree7640abd7e7d7c48cbb064e66564b9e33204022d0 /drivers
parent483e4a1d83db1a6d339cd76f7966bf9e1748f752 (diff)
parentfe7c758c07c4729a16f940eb1d77027ad032ab29 (diff)
downloadlinux-3784fad934c5bd68551f0af4252821697957a72a.tar.bz2
Merge tag 'pm-5.19-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management fixes from Rafael Wysocki: "These fix a NULL pointer dereference in a devfreq driver and a runtime PM framework issue that may cause a supplier device to be suspended before its consumer. Specifics: - Fix NULL pointer dereference related to printing a diagnostic message in the exynos-bus devfreq driver (Christian Marangi) - Fix race condition in the runtime PM framework which in some cases may cause a supplier device to be suspended when its consumer is still active (Rafael Wysocki)" * tag 'pm-5.19-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: PM / devfreq: exynos-bus: Fix NULL pointer dereference PM: runtime: Fix supplier device management during consumer probe PM: runtime: Redefine pm_runtime_release_supplier()
Diffstat (limited to 'drivers')
-rw-r--r--drivers/base/core.c13
-rw-r--r--drivers/base/power/runtime.c34
-rw-r--r--drivers/devfreq/exynos-bus.c6
3 files changed, 25 insertions, 28 deletions
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 7cd789c4985d..460d6f163e41 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -486,7 +486,18 @@ static void device_link_release_fn(struct work_struct *work)
/* Ensure that all references to the link object have been dropped. */
device_link_synchronize_removal();
- pm_runtime_release_supplier(link, true);
+ pm_runtime_release_supplier(link);
+ /*
+ * If supplier_preactivated is set, the link has been dropped between
+ * the pm_runtime_get_suppliers() and pm_runtime_put_suppliers() calls
+ * in __driver_probe_device(). In that case, drop the supplier's
+ * PM-runtime usage counter to remove the reference taken by
+ * pm_runtime_get_suppliers().
+ */
+ if (link->supplier_preactivated)
+ pm_runtime_put_noidle(link->supplier);
+
+ pm_request_idle(link->supplier);
put_device(link->consumer);
put_device(link->supplier);
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index 676dc72d912d..949907e2e242 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -308,13 +308,10 @@ static int rpm_get_suppliers(struct device *dev)
/**
* pm_runtime_release_supplier - Drop references to device link's supplier.
* @link: Target device link.
- * @check_idle: Whether or not to check if the supplier device is idle.
*
- * Drop all runtime PM references associated with @link to its supplier device
- * and if @check_idle is set, check if that device is idle (and so it can be
- * suspended).
+ * Drop all runtime PM references associated with @link to its supplier device.
*/
-void pm_runtime_release_supplier(struct device_link *link, bool check_idle)
+void pm_runtime_release_supplier(struct device_link *link)
{
struct device *supplier = link->supplier;
@@ -327,9 +324,6 @@ void pm_runtime_release_supplier(struct device_link *link, bool check_idle)
while (refcount_dec_not_one(&link->rpm_active) &&
atomic_read(&supplier->power.usage_count) > 0)
pm_runtime_put_noidle(supplier);
-
- if (check_idle)
- pm_request_idle(supplier);
}
static void __rpm_put_suppliers(struct device *dev, bool try_to_suspend)
@@ -337,8 +331,11 @@ static void __rpm_put_suppliers(struct device *dev, bool try_to_suspend)
struct device_link *link;
list_for_each_entry_rcu(link, &dev->links.suppliers, c_node,
- device_links_read_lock_held())
- pm_runtime_release_supplier(link, try_to_suspend);
+ device_links_read_lock_held()) {
+ pm_runtime_release_supplier(link);
+ if (try_to_suspend)
+ pm_request_idle(link->supplier);
+ }
}
static void rpm_put_suppliers(struct device *dev)
@@ -1771,7 +1768,6 @@ void pm_runtime_get_suppliers(struct device *dev)
if (link->flags & DL_FLAG_PM_RUNTIME) {
link->supplier_preactivated = true;
pm_runtime_get_sync(link->supplier);
- refcount_inc(&link->rpm_active);
}
device_links_read_unlock(idx);
@@ -1791,19 +1787,8 @@ void pm_runtime_put_suppliers(struct device *dev)
list_for_each_entry_rcu(link, &dev->links.suppliers, c_node,
device_links_read_lock_held())
if (link->supplier_preactivated) {
- bool put;
-
link->supplier_preactivated = false;
-
- spin_lock_irq(&dev->power.lock);
-
- put = pm_runtime_status_suspended(dev) &&
- refcount_dec_not_one(&link->rpm_active);
-
- spin_unlock_irq(&dev->power.lock);
-
- if (put)
- pm_runtime_put(link->supplier);
+ pm_runtime_put(link->supplier);
}
device_links_read_unlock(idx);
@@ -1838,7 +1823,8 @@ void pm_runtime_drop_link(struct device_link *link)
return;
pm_runtime_drop_link_count(link->consumer);
- pm_runtime_release_supplier(link, true);
+ pm_runtime_release_supplier(link);
+ pm_request_idle(link->supplier);
}
static bool pm_runtime_need_not_resume(struct device *dev)
diff --git a/drivers/devfreq/exynos-bus.c b/drivers/devfreq/exynos-bus.c
index e689101abc93..f7dcc44f9414 100644
--- a/drivers/devfreq/exynos-bus.c
+++ b/drivers/devfreq/exynos-bus.c
@@ -447,9 +447,9 @@ static int exynos_bus_probe(struct platform_device *pdev)
}
}
- max_state = bus->devfreq->profile->max_state;
- min_freq = (bus->devfreq->profile->freq_table[0] / 1000);
- max_freq = (bus->devfreq->profile->freq_table[max_state - 1] / 1000);
+ max_state = bus->devfreq->max_state;
+ min_freq = (bus->devfreq->freq_table[0] / 1000);
+ max_freq = (bus->devfreq->freq_table[max_state - 1] / 1000);
pr_info("exynos-bus: new bus device registered: %s (%6ld KHz ~ %6ld KHz)\n",
dev_name(dev), min_freq, max_freq);