[PATCH v8 1/4] driver core: don't always lock parent in shutdown

Stuart Hayes
2024-08-22T20:28:15Z

Don't lock a parent device unless it is needed in device_shutdown. This
is in preparation for making device shutdown asynchronous, when it will
be needed to allow children of a common parent to shut down
simultaneously.

Signed-off-by: Stuart Hayes <stuart.w.hayes@gmail.com>
Signed-off-by: David Jeffery <djeffery@redhat.com>
---
drivers/base/core.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 8c0733d3aad8..13253d105062 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -4818,7 +4818,7 @@ void device_shutdown(void)
spin_unlock(&devices_kset->list_lock);

/* hold lock to avoid race with probe/release */
- if (parent)
+ if (parent && dev->bus && dev->bus->need_parent_lock)
device_lock(parent);
device_lock(dev);

@@ -4842,7 +4842,7 @@ void device_shutdown(void)
}

device_unlock(dev);
- if (parent)
+ if (parent && dev->bus && dev->bus->need_parent_lock)
device_unlock(parent);

put_device(dev);
--
2.39.3