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driver core: Do not resume suppliers under device_links_write_lock()
It is incorrect to call pm_runtime_get_sync() under device_links_write_lock(), because it may end up trying to take device_links_read_lock() while resuming the target device and that will deadlock in the non-SRCU case, so avoid that by resuming the supplier device in device_link_add() before calling device_links_write_lock(). Fixes:21d5c57b37
("PM / runtime: Use device links") Fixes:baa8809f60
("PM / runtime: Optimize the use of device links") Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
parent
f265df550a
commit
5db25c9eb8
1 changed files with 14 additions and 6 deletions
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@ -201,12 +201,21 @@ struct device_link *device_link_add(struct device *consumer,
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struct device *supplier, u32 flags)
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{
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struct device_link *link;
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bool rpm_put_supplier = false;
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if (!consumer || !supplier ||
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(flags & DL_FLAG_STATELESS &&
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flags & (DL_FLAG_AUTOREMOVE_CONSUMER | DL_FLAG_AUTOREMOVE_SUPPLIER)))
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return NULL;
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if (flags & DL_FLAG_PM_RUNTIME && flags & DL_FLAG_RPM_ACTIVE) {
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if (pm_runtime_get_sync(supplier) < 0) {
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pm_runtime_put_noidle(supplier);
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return NULL;
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}
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rpm_put_supplier = true;
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}
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device_links_write_lock();
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device_pm_lock();
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@ -250,13 +259,8 @@ struct device_link *device_link_add(struct device *consumer,
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if (flags & DL_FLAG_PM_RUNTIME) {
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if (flags & DL_FLAG_RPM_ACTIVE) {
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if (pm_runtime_get_sync(supplier) < 0) {
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pm_runtime_put_noidle(supplier);
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kfree(link);
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link = NULL;
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goto out;
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}
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link->rpm_active = true;
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rpm_put_supplier = false;
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}
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pm_runtime_new_link(consumer);
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/*
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@ -328,6 +332,10 @@ struct device_link *device_link_add(struct device *consumer,
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out:
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device_pm_unlock();
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device_links_write_unlock();
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if (rpm_put_supplier)
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pm_runtime_put(supplier);
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return link;
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}
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EXPORT_SYMBOL_GPL(device_link_add);
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