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| author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2019-02-01 01:47:53 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-02-01 10:04:08 +0100 |
| commit | 5db25c9eb893df8f6b93c1d97b8006d768e1b6f5 (patch) | |
| tree | b4a98023165114a5539d9804089fb1f4493e4caa /drivers/base/core.c | |
| parent | f265df550a4350dce0a4d721a77c52e4b847ea40 (diff) | |
| download | lwn-5db25c9eb893df8f6b93c1d97b8006d768e1b6f5.tar.gz lwn-5db25c9eb893df8f6b93c1d97b8006d768e1b6f5.zip | |
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: 21d5c57b3726 ("PM / runtime: Use device links")
Fixes: baa8809f6097 ("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>
Diffstat (limited to 'drivers/base/core.c')
| -rw-r--r-- | drivers/base/core.c | 20 |
1 files changed, 14 insertions, 6 deletions
diff --git a/drivers/base/core.c b/drivers/base/core.c index a4d6f9b93088..50610cd87e71 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -201,12 +201,21 @@ struct device_link *device_link_add(struct device *consumer, struct device *supplier, u32 flags) { struct device_link *link; + bool rpm_put_supplier = false; if (!consumer || !supplier || (flags & DL_FLAG_STATELESS && flags & (DL_FLAG_AUTOREMOVE_CONSUMER | DL_FLAG_AUTOREMOVE_SUPPLIER))) return NULL; + if (flags & DL_FLAG_PM_RUNTIME && flags & DL_FLAG_RPM_ACTIVE) { + if (pm_runtime_get_sync(supplier) < 0) { + pm_runtime_put_noidle(supplier); + return NULL; + } + rpm_put_supplier = true; + } + device_links_write_lock(); device_pm_lock(); @@ -250,13 +259,8 @@ struct device_link *device_link_add(struct device *consumer, if (flags & DL_FLAG_PM_RUNTIME) { if (flags & DL_FLAG_RPM_ACTIVE) { - if (pm_runtime_get_sync(supplier) < 0) { - pm_runtime_put_noidle(supplier); - kfree(link); - link = NULL; - goto out; - } link->rpm_active = true; + rpm_put_supplier = false; } pm_runtime_new_link(consumer); /* @@ -328,6 +332,10 @@ struct device_link *device_link_add(struct device *consumer, out: device_pm_unlock(); device_links_write_unlock(); + + if (rpm_put_supplier) + pm_runtime_put(supplier); + return link; } EXPORT_SYMBOL_GPL(device_link_add); |