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authorRafael J. Wysocki2019-02-01 01:59:42 +0100
committerGreg Kroah-Hartman2019-02-01 10:04:08 +0100
commite7dd40105aac9ba051e44ad711123bc53a5e4c71 (patch)
treebce4bbd7d389e5e84b369156f8ee266a906628ed /drivers/base/core.c
parentdriver core: Make driver core own stateful device links (diff)
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driver core: Add device link flag DL_FLAG_AUTOPROBE_CONSUMER
Add a new device link flag, DL_FLAG_AUTOPROBE_CONSUMER, to request the driver core to probe for a consumer driver automatically after binding a driver to the supplier device on a persistent managed device link. As unbinding the supplier driver on a managed device link causes the consumer driver to be detached from its device automatically, this flag provides a complementary mechanism which is needed to address some "composite device" use cases. 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.c16
1 files changed, 15 insertions, 1 deletions
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 9d49b461b1d9..abfce4f613f8 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -208,6 +208,12 @@ static void device_link_rpm_prepare(struct device *consumer,
* the link will be maintained until one of the devices pointed to by it (either
* the consumer or the supplier) is unregistered.
*
+ * Also, if DL_FLAG_STATELESS, DL_FLAG_AUTOREMOVE_CONSUMER and
+ * DL_FLAG_AUTOREMOVE_SUPPLIER are not set in @flags (that is, a persistent
+ * managed device link is being added), the DL_FLAG_AUTOPROBE_CONSUMER flag can
+ * be used to request the driver core to automaticall probe for a consmer
+ * driver after successfully binding a driver to the supplier device.
+ *
* The combination of DL_FLAG_STATELESS and either DL_FLAG_AUTOREMOVE_CONSUMER
* or DL_FLAG_AUTOREMOVE_SUPPLIER set in @flags at the same time is invalid and
* will cause NULL to be returned upfront.
@@ -228,7 +234,12 @@ struct device_link *device_link_add(struct device *consumer,
if (!consumer || !supplier ||
(flags & DL_FLAG_STATELESS &&
- flags & (DL_FLAG_AUTOREMOVE_CONSUMER | DL_FLAG_AUTOREMOVE_SUPPLIER)))
+ flags & (DL_FLAG_AUTOREMOVE_CONSUMER |
+ DL_FLAG_AUTOREMOVE_SUPPLIER |
+ DL_FLAG_AUTOPROBE_CONSUMER)) ||
+ (flags & DL_FLAG_AUTOPROBE_CONSUMER &&
+ flags & (DL_FLAG_AUTOREMOVE_CONSUMER |
+ DL_FLAG_AUTOREMOVE_SUPPLIER)))
return NULL;
if (flags & DL_FLAG_PM_RUNTIME && flags & DL_FLAG_RPM_ACTIVE) {
@@ -589,6 +600,9 @@ void device_links_driver_bound(struct device *dev)
WARN_ON(link->status != DL_STATE_DORMANT);
WRITE_ONCE(link->status, DL_STATE_AVAILABLE);
+
+ if (link->flags & DL_FLAG_AUTOPROBE_CONSUMER)
+ driver_deferred_probe_add(link->consumer);
}
list_for_each_entry(link, &dev->links.suppliers, c_node) {