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: Alan Tull <atull@opensource.altera.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c
index 2526163..68d7b41 100644
--- a/drivers/fpga/fpga-mgr.c
+++ b/drivers/fpga/fpga-mgr.c
@@ -204,9 +204,7 @@
{
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 @@
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 @@
*/
void fpga_mgr_put(struct fpga_manager *mgr)
{
- if (mgr) {
- module_put(THIS_MODULE);
- mutex_unlock(&mgr->ref_mutex);
- }
+ module_put(mgr->dev.parent->driver->owner);
+ mutex_unlock(&mgr->ref_mutex);
+ put_device(&mgr->dev);
}
EXPORT_SYMBOL_GPL(fpga_mgr_put);