diff mbox series

[v2,09/17] driver core: Allow only unprobed consumers for SYNC_STATE_ONLY device links

Message ID 20201121020232.908850-10-saravanak@google.com
State Accepted
Commit ac66c5bbb4371073dcace77e47c234d2e36a006b
Headers show
Series Refactor fw_devlink to significantly improve boot time | expand

Commit Message

Saravana Kannan Nov. 21, 2020, 2:02 a.m. UTC 
SYNC_STATE_ONLY device links only affect the behavior of sync_state()
callbacks. Specifically, they prevent sync_state() only callbacks from
being called on a device if one or more of its consumers haven't probed.

So, creating a SYNC_STATE_ONLY device link from an already probed
consumer is useless. So, don't allow creating such device links.

Signed-off-by: Saravana Kannan <saravanak@google.com>
---
 drivers/base/core.c | 11 +++++++++++
 1 file changed, 11 insertions(+)
diff mbox series

Patch

diff --git a/drivers/base/core.c b/drivers/base/core.c
index e2b246a44d1a..215ce9e72790 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -649,6 +649,17 @@  struct device_link *device_link_add(struct device *consumer,
 		goto out;
 	}
 
+	/*
+	 * SYNC_STATE_ONLY links are useless once a consumer device has probed.
+	 * So, only create it if the consumer hasn't probed yet.
+	 */
+	if (flags & DL_FLAG_SYNC_STATE_ONLY &&
+	    consumer->links.status != DL_DEV_NO_DRIVER &&
+	    consumer->links.status != DL_DEV_PROBING) {
+		link = NULL;
+		goto out;
+	}
+
 	/*
 	 * DL_FLAG_AUTOREMOVE_SUPPLIER indicates that the link will be needed
 	 * longer than for DL_FLAG_AUTOREMOVE_CONSUMER and setting them both