[Resend][PATCH v4 1/5] driver core: Add a wrapper around __device_release_driver()
From: Rafael J. Wysocki <hidden>
Date: 2016-09-29 00:36:17
Also in:
lkml
Subsystem:
driver core, kobjects, debugfs and sysfs, the rest · Maintainers:
Greg Kroah-Hartman, "Rafael J. Wysocki", Danilo Krummrich, Linus Torvalds
From: Rafael J. Wysocki <redacted> Add an internal wrapper around __device_release_driver() that will acquire device locks and do the necessary checks before calling it. The next patch will make use of it. Signed-off-by: Rafael J. Wysocki <redacted> --- drivers/base/dd.c | 30 ++++++++++++++++++------------ 1 file changed, 18 insertions(+), 12 deletions(-)
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 16688f50729c..d9e76e9205c7 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c@@ -796,6 +796,22 @@ static void __device_release_driver(struct device *dev) } } +static void device_release_driver_internal(struct device *dev, + struct device_driver *drv, + struct device *parent) +{ + if (parent) + device_lock(parent); + + device_lock(dev); + if (!drv || drv == dev->driver) + __device_release_driver(dev); + + device_unlock(dev); + if (parent) + device_unlock(parent); +} + /** * device_release_driver - manually detach device from driver. * @dev: device.
@@ -810,9 +826,7 @@ void device_release_driver(struct device *dev) * within their ->remove callback for the same device, they * will deadlock right here. */ - device_lock(dev); - __device_release_driver(dev); - device_unlock(dev); + device_release_driver_internal(dev, NULL, NULL); } EXPORT_SYMBOL_GPL(device_release_driver);
@@ -837,15 +851,7 @@ void driver_detach(struct device_driver *drv) dev = dev_prv->device; get_device(dev); spin_unlock(&drv->p->klist_devices.k_lock); - - if (dev->parent) /* Needed for USB */ - device_lock(dev->parent); - device_lock(dev); - if (dev->driver == drv) - __device_release_driver(dev); - device_unlock(dev); - if (dev->parent) - device_unlock(dev->parent); + device_release_driver_internal(dev, drv, dev->parent); put_device(dev); } }