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authorAlexander Usyskin <alexander.usyskin@intel.com>2017-01-27 16:32:39 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-01-31 11:07:43 +0100
commit5d88246090c5e9b178eb05bcfb52bbaad2ae48f3 (patch)
tree35fba5dcc29e9a348d925ab900e2b69ee1346f69 /drivers/misc/mei
parent9ecb839f16a353e71175981a098842fda4ddc7f1 (diff)
downloadlinux-5d88246090c5e9b178eb05bcfb52bbaad2ae48f3.tar.bz2
mei: bus: prevent hardware module unload if device on bus is active
The hardware module should not be unloaded if the bus has active devices. Get get_/put_ bus parent module upon client device connection/disconnection, to prevent the hardware managing module to disappear underneath. Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/misc/mei')
-rw-r--r--drivers/misc/mei/bus.c31
-rw-r--r--drivers/misc/mei/client.c10
-rw-r--r--drivers/misc/mei/mei_dev.h2
3 files changed, 41 insertions, 2 deletions
diff --git a/drivers/misc/mei/bus.c b/drivers/misc/mei/bus.c
index 3bb1f1500f6b..b67f15b53067 100644
--- a/drivers/misc/mei/bus.c
+++ b/drivers/misc/mei/bus.c
@@ -542,6 +542,37 @@ out:
EXPORT_SYMBOL_GPL(mei_cldev_disable);
/**
+ * mei_cl_bus_module_get - acquire module of the underlying
+ * hw module.
+ *
+ * @cl: host client
+ *
+ * Return: true on success; false if the module was removed.
+ */
+bool mei_cl_bus_module_get(struct mei_cl *cl)
+{
+ struct mei_cl_device *cldev = cl->cldev;
+
+ if (!cldev)
+ return true;
+
+ return try_module_get(cldev->bus->dev->driver->owner);
+}
+
+/**
+ * mei_cl_bus_module_put - release the underlying hw module.
+ *
+ * @cl: host client
+ */
+void mei_cl_bus_module_put(struct mei_cl *cl)
+{
+ struct mei_cl_device *cldev = cl->cldev;
+
+ if (cldev)
+ module_put(cldev->bus->dev->driver->owner);
+}
+
+/**
* mei_cl_device_find - find matching entry in the driver id table
*
* @cldev: me client device
diff --git a/drivers/misc/mei/client.c b/drivers/misc/mei/client.c
index da1c0703910a..619b4702347f 100644
--- a/drivers/misc/mei/client.c
+++ b/drivers/misc/mei/client.c
@@ -774,6 +774,8 @@ static void mei_cl_set_disconnected(struct mei_cl *cl)
cl->tx_flow_ctrl_creds = 0;
cl->timer_count = 0;
+ mei_cl_bus_module_put(cl);
+
if (!cl->me_cl)
return;
@@ -1077,13 +1079,17 @@ int mei_cl_connect(struct mei_cl *cl, struct mei_me_client *me_cl,
dev = cl->dev;
+ if (!mei_cl_bus_module_get(cl))
+ return -ENODEV;
+
rets = mei_cl_set_connecting(cl, me_cl);
if (rets)
- return rets;
+ goto nortpm;
if (mei_cl_is_fixed_address(cl)) {
cl->state = MEI_FILE_CONNECTED;
- return 0;
+ rets = 0;
+ goto nortpm;
}
rets = pm_runtime_get(dev->dev);
diff --git a/drivers/misc/mei/mei_dev.h b/drivers/misc/mei/mei_dev.h
index 8dadb98662a9..33ff4b7e356d 100644
--- a/drivers/misc/mei/mei_dev.h
+++ b/drivers/misc/mei/mei_dev.h
@@ -328,6 +328,8 @@ ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length,
bool mei_cl_bus_rx_event(struct mei_cl *cl);
bool mei_cl_bus_notify_event(struct mei_cl *cl);
void mei_cl_bus_remove_devices(struct mei_device *bus);
+bool mei_cl_bus_module_get(struct mei_cl *cl);
+void mei_cl_bus_module_put(struct mei_cl *cl);
int mei_cl_bus_init(void);
void mei_cl_bus_exit(void);