diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-07-08 13:01:04 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-07-08 13:01:04 -0700 |
commit | 3784fad934c5bd68551f0af4252821697957a72a (patch) | |
tree | 7640abd7e7d7c48cbb064e66564b9e33204022d0 /drivers | |
parent | 483e4a1d83db1a6d339cd76f7966bf9e1748f752 (diff) | |
parent | fe7c758c07c4729a16f940eb1d77027ad032ab29 (diff) | |
download | linux-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.c | 13 | ||||
-rw-r--r-- | drivers/base/power/runtime.c | 34 | ||||
-rw-r--r-- | drivers/devfreq/exynos-bus.c | 6 |
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); |