[PATCH 5.4 48/74] PM: runtime: Fix ordering in pm_runtime_get_suppliers()

Greg Kroah-Hartman
2021-04-05T09:06:28Z

From: Adrian Hunter <adrian.hunter@intel.com>

commit c0c33442f7203704aef345647e14c2fb86071001 upstream.

rpm_active indicates how many times the supplier usage_count has been
incremented. Consequently it must be updated after pm_runtime_get_sync() of
the supplier, not before.

Fixes: 4c06c4e6cf63 ("driver core: Fix possible supplier PM-usage counter imbalance")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: 5.1+ <stable@vger.kernel.org> # 5.1+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/base/power/runtime.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -1663,8 +1663,8 @@ void pm_runtime_get_suppliers(struct dev
device_links_read_lock_held())
if (link->flags & DL_FLAG_PM_RUNTIME) {
link->supplier_preactivated = true;
- refcount_inc(&link->rpm_active);
pm_runtime_get_sync(link->supplier);
+ refcount_inc(&link->rpm_active);
}

device_links_read_unlock(idx);