[PATCH v2 09/17] driver core: Allow only unprobed consumers for SYNC_STATE_ONLY device links
From: Saravana Kannan <hidden>
Date: 2020-11-21 02:04:00
Also in:
linux-acpi, linux-efi, lkml
Subsystem:
driver core, kobjects, debugfs and sysfs, the rest · Maintainers:
Greg Kroah-Hartman, "Rafael J. Wysocki", Danilo Krummrich, Linus Torvalds
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 <redacted> --- drivers/base/core.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
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
--
2.29.2.454.gaff20da3a2-goog