[char-misc-next 09/15 V2] mei: bus: add reference to bus device in struct mei_cl_client

From: Tomas Winkler
Date: Mon Jun 15 2015 - 14:58:34 EST


Add reference to the bus device (mei_device) for easier access.
To ensures that referencing cldev->bus is valid during cldev life time
we increase the bus ref counter on a client device creation and drop it
on the device release.

Signed-off-by: Tomas Winkler <tomas.winkler@xxxxxxxxx>
---
V2: resend
drivers/misc/mei/bus.c | 17 +++++++++++++++++
include/linux/mei_cl_bus.h | 3 +++
2 files changed, 20 insertions(+)

diff --git a/drivers/misc/mei/bus.c b/drivers/misc/mei/bus.c
index 88cca46bddcb..2f690c76e047 100644
--- a/drivers/misc/mei/bus.c
+++ b/drivers/misc/mei/bus.c
@@ -589,6 +589,20 @@ static struct bus_type mei_cl_bus_type = {
.uevent = mei_cl_device_uevent,
};

+static struct mei_device *mei_dev_bus_get(struct mei_device *bus)
+{
+ if (bus)
+ get_device(bus->dev);
+
+ return bus;
+}
+
+static void mei_dev_bus_put(struct mei_device *bus)
+{
+ if (bus)
+ put_device(bus->dev);
+}
+
static void mei_cl_dev_release(struct device *dev)
{
struct mei_cl_device *cldev = to_mei_cl_device(dev);
@@ -597,6 +611,7 @@ static void mei_cl_dev_release(struct device *dev)
return;

mei_me_cl_put(cldev->me_cl);
+ mei_dev_bus_put(cldev->bus);
kfree(cldev);
}

@@ -640,6 +655,7 @@ struct mei_cl_device *mei_cl_add_device(struct mei_device *bus,
cldev->dev.parent = bus->dev;
cldev->dev.bus = &mei_cl_bus_type;
cldev->dev.type = &mei_cl_device_type;
+ cldev->bus = mei_dev_bus_get(bus);

strlcpy(cldev->name, name, sizeof(cldev->name));

@@ -649,6 +665,7 @@ struct mei_cl_device *mei_cl_add_device(struct mei_device *bus,
if (status) {
dev_err(bus->dev, "Failed to register MEI device\n");
mei_me_cl_put(cldev->me_cl);
+ mei_dev_bus_put(bus);
kfree(cldev);
return NULL;
}
diff --git a/include/linux/mei_cl_bus.h b/include/linux/mei_cl_bus.h
index a16b1f9c1aca..4c5c25b3222c 100644
--- a/include/linux/mei_cl_bus.h
+++ b/include/linux/mei_cl_bus.h
@@ -6,6 +6,7 @@
#include <linux/mod_devicetable.h>

struct mei_cl_device;
+struct mei_device;

typedef void (*mei_cl_event_cb_t)(struct mei_cl_device *device,
u32 events, void *context);
@@ -17,6 +18,7 @@ typedef void (*mei_cl_event_cb_t)(struct mei_cl_device *device,
* Drivers for MEI devices will get an mei_cl_device pointer
* when being probed and shall use it for doing ME bus I/O.
*
+ * @bus: parent mei device
* @dev: linux driver model device pointer
* @me_cl: me client
* @cl: mei client
@@ -29,6 +31,7 @@ typedef void (*mei_cl_event_cb_t)(struct mei_cl_device *device,
* @priv_data: client private data
*/
struct mei_cl_device {
+ struct mei_device *bus;
struct device dev;

struct mei_me_client *me_cl;
--
2.4.3

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