[PATCH v1 6/6] driver core: Fix creation of device links with PM-runtime flags

[Saravana Kannan]

From: "Rafael J. Wysocki" <rafael.j.wysocki@xxxxxxxxx>

After commit 515db266a9da ("driver core: Remove device link creation
limitation"), if PM-runtime flags are passed to device_link_add(), it
will fail (returning NULL) due to an overly restrictive flags check
introduced by that commit.

Fix this issue by extending the check in question to cover the
PM-runtime flags too.

Fixes: 515db266a9da ("driver core: Remove device link creation limitation")
Reported-by: Dmitry Osipenko <digetx@xxxxxxxxx>
Tested-by: Jon Hunter <jonathanh@xxxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Tested-by: Dmitry Osipenko <digetx@xxxxxxxxx>
Tested-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/7674989.cD04D8YV3U@kreacher
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
(cherry picked from commit fb583c8eeeb1fd57e24ef41ed94c9112067aeac9)
Signed-off-by: Saravana Kannan <saravanak@xxxxxxxxxx>
---
 drivers/base/core.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 31007af4cb79..928fc1532a70 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -213,6 +213,9 @@ void device_pm_move_to_tail(struct device *dev)
 			       DL_FLAG_AUTOREMOVE_SUPPLIER | \
 			       DL_FLAG_AUTOPROBE_CONSUMER)
 
+#define DL_ADD_VALID_FLAGS (DL_MANAGED_LINK_FLAGS | DL_FLAG_STATELESS | \
+			    DL_FLAG_PM_RUNTIME | DL_FLAG_RPM_ACTIVE)
+
 /**
  * device_link_add - Create a link between two devices.
  * @consumer: Consumer end of the link.
@@ -274,8 +277,7 @@ struct device_link *device_link_add(struct device *consumer,
 {
 	struct device_link *link;
 
-	if (!consumer || !supplier ||
-	    (flags & ~(DL_FLAG_STATELESS | DL_MANAGED_LINK_FLAGS)) ||
+	if (!consumer || !supplier || flags & ~DL_ADD_VALID_FLAGS ||
 	    (flags & DL_FLAG_STATELESS && flags & DL_MANAGED_LINK_FLAGS) ||
 	    (flags & DL_FLAG_AUTOPROBE_CONSUMER &&
 	     flags & (DL_FLAG_AUTOREMOVE_CONSUMER |
-- 
2.25.1.481.gfbce0eb801-goog