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Commit 654ba4cc authored by Alan Tull's avatar Alan Tull Committed by Greg Kroah-Hartman
Browse files

fpga manager: ensure lifetime with of_fpga_mgr_get 



Ensure device and driver lifetime from of_fpga_mgr_get() to
fpga_mgr_put().

* Don't put_device() in of_fpga_mgr_get, do it in fpga_mgr_put().
  (still do put_device if there is an error).
* Do module_get on the low level driver.
* Don't need to module_get(THIS_MODULE) since we won't be allowed
  to unload the fpga manager core without unloading low level
  driver first.
* Remove unnedessary null check for node pointer.

Signed-off-by: default avatarAlan Tull <atull@opensource.altera.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 4d10eaff

drivers/fpga/fpga-mgr.c

+17 −15
Original line number Diff line number Diff line
@@ -204,9 +204,7 @@ struct fpga_manager *of_fpga_mgr_get(struct device_node *node) 
{

	struct fpga_manager *mgr;

	struct device *dev;



	if (!node)

		return ERR_PTR(-EINVAL);

	int ret = -ENODEV;



	dev = class_find_device(fpga_mgr_class, NULL, node,

				fpga_mgr_of_node_match);
@@ -214,20 +212,25 @@ struct fpga_manager *of_fpga_mgr_get(struct device_node *node) 
		return ERR_PTR(-ENODEV);



	mgr = to_fpga_manager(dev);

	put_device(dev);

	if (!mgr)

		return ERR_PTR(-ENODEV);

		goto err_dev;



	/* Get exclusive use of fpga manager */

	if (!mutex_trylock(&mgr->ref_mutex))

		return ERR_PTR(-EBUSY);



	if (!try_module_get(THIS_MODULE)) {

		mutex_unlock(&mgr->ref_mutex);

		return ERR_PTR(-ENODEV);

	if (!mutex_trylock(&mgr->ref_mutex)) {

		ret = -EBUSY;

		goto err_dev;

	}



	if (!try_module_get(dev->parent->driver->owner))

		goto err_ll_mod;



	return mgr;



err_ll_mod:

	mutex_unlock(&mgr->ref_mutex);

err_dev:

	put_device(dev);

	return ERR_PTR(ret);

}

EXPORT_SYMBOL_GPL(of_fpga_mgr_get);
@@ -237,10 +240,9 @@ EXPORT_SYMBOL_GPL(of_fpga_mgr_get); 
 */

void fpga_mgr_put(struct fpga_manager *mgr)

{

	if (mgr) {

		module_put(THIS_MODULE);

	module_put(mgr->dev.parent->driver->owner);

	mutex_unlock(&mgr->ref_mutex);

	}

	put_device(&mgr->dev);

}

EXPORT_SYMBOL_GPL(fpga_mgr_put);