[PATCH v6 1/3] drivers core: refactor device_shutdown

From: Pavel Tatashin
Date: Fri Jun 29 2018 - 14:26:29 EST


device_shutdown() traverses through the list of devices, and calls
dev->{bug/driver}->shutdown() for each entry in the list.

Refactor the function by keeping device_shutdown() to do the logic of
traversing the list of devices, and device_shutdown_one() to perform the
actual shutdown operation on one device.

Signed-off-by: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
---
drivers/base/core.c | 50 +++++++++++++++++++++++++++------------------
1 file changed, 30 insertions(+), 20 deletions(-)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index df3e1a44707a..07380aa0683b 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -2802,6 +2802,35 @@ int device_move(struct device *dev, struct device *new_parent,
}
EXPORT_SYMBOL_GPL(device_move);

+/*
+ * device_shutdown_one - call ->shutdown() for the device passed as
+ * argument.
+ */
+static void device_shutdown_one(struct device *dev)
+{
+ /* Don't allow any more runtime suspends */
+ pm_runtime_get_noresume(dev);
+ pm_runtime_barrier(dev);
+
+ if (dev->class && dev->class->shutdown_pre) {
+ if (initcall_debug)
+ dev_info(dev, "shutdown_pre\n");
+ dev->class->shutdown_pre(dev);
+ }
+ if (dev->bus && dev->bus->shutdown) {
+ if (initcall_debug)
+ dev_info(dev, "shutdown\n");
+ dev->bus->shutdown(dev);
+ } else if (dev->driver && dev->driver->shutdown) {
+ if (initcall_debug)
+ dev_info(dev, "shutdown\n");
+ dev->driver->shutdown(dev);
+ }
+
+ /* decrement the reference counter */
+ put_device(dev);
+}
+
/**
* device_shutdown - call ->shutdown() on each device to shutdown.
*/
@@ -2838,30 +2867,11 @@ void device_shutdown(void)
device_lock(parent);
device_lock(dev);

- /* Don't allow any more runtime suspends */
- pm_runtime_get_noresume(dev);
- pm_runtime_barrier(dev);
-
- if (dev->class && dev->class->shutdown_pre) {
- if (initcall_debug)
- dev_info(dev, "shutdown_pre\n");
- dev->class->shutdown_pre(dev);
- }
- if (dev->bus && dev->bus->shutdown) {
- if (initcall_debug)
- dev_info(dev, "shutdown\n");
- dev->bus->shutdown(dev);
- } else if (dev->driver && dev->driver->shutdown) {
- if (initcall_debug)
- dev_info(dev, "shutdown\n");
- dev->driver->shutdown(dev);
- }
-
+ device_shutdown_one(dev);
device_unlock(dev);
if (parent)
device_unlock(parent);

- put_device(dev);
put_device(parent);

spin_lock(&devices_kset->list_lock);
--
2.18.0