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path: root/drivers/base/dd.c
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Diffstat (limited to 'drivers/base/dd.c')
-rw-r--r--drivers/base/dd.c66
1 files changed, 35 insertions, 31 deletions
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 6a48824e43ff..18dba8e78da7 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -94,19 +94,11 @@ int device_bind_driver(struct device *dev)
return ret;
}
-struct stupid_thread_structure {
- struct device_driver *drv;
- struct device *dev;
-};
-
static atomic_t probe_count = ATOMIC_INIT(0);
static DECLARE_WAIT_QUEUE_HEAD(probe_waitqueue);
-static int really_probe(void *void_data)
+static int really_probe(struct device *dev, struct device_driver *drv)
{
- struct stupid_thread_structure *data = void_data;
- struct device_driver *drv = data->drv;
- struct device *dev = data->dev;
int ret = 0;
atomic_inc(&probe_count);
@@ -154,7 +146,6 @@ probe_failed:
*/
ret = 0;
done:
- kfree(data);
atomic_dec(&probe_count);
wake_up(&probe_waitqueue);
return ret;
@@ -186,16 +177,14 @@ int driver_probe_done(void)
* format of the ID structures, nor what is to be considered a match and
* what is not.
*
- * This function returns 1 if a match is found, an error if one occurs
- * (that is not -ENODEV or -ENXIO), and 0 otherwise.
+ * This function returns 1 if a match is found, -ENODEV if the device is
+ * not registered, and 0 otherwise.
*
* This function must be called with @dev->sem held. When called for a
* USB interface, @dev->parent->sem must be held as well.
*/
int driver_probe_device(struct device_driver * drv, struct device * dev)
{
- struct stupid_thread_structure *data;
- struct task_struct *probe_task;
int ret = 0;
if (!device_is_registered(dev))
@@ -206,19 +195,7 @@ int driver_probe_device(struct device_driver * drv, struct device * dev)
pr_debug("%s: Matched Device %s with Driver %s\n",
drv->bus->name, dev->bus_id, drv->name);
- data = kmalloc(sizeof(*data), GFP_KERNEL);
- if (!data)
- return -ENOMEM;
- data->drv = drv;
- data->dev = dev;
-
- if (drv->multithread_probe) {
- probe_task = kthread_run(really_probe, data,
- "probe-%s", dev->bus_id);
- if (IS_ERR(probe_task))
- ret = really_probe(data);
- } else
- ret = really_probe(data);
+ ret = really_probe(dev, drv);
done:
return ret;
@@ -230,30 +207,57 @@ static int __device_attach(struct device_driver * drv, void * data)
return driver_probe_device(drv, dev);
}
+static int device_probe_drivers(void *data)
+{
+ struct device *dev = data;
+ int ret = 0;
+
+ if (dev->bus) {
+ down(&dev->sem);
+ ret = bus_for_each_drv(dev->bus, NULL, dev, __device_attach);
+ up(&dev->sem);
+ }
+ return ret;
+}
+
/**
* device_attach - try to attach device to a driver.
* @dev: device.
*
* Walk the list of drivers that the bus has and call
* driver_probe_device() for each pair. If a compatible
- * pair is found, break out and return.
+ * pair is found, break out and return. If the bus specifies
+ * multithreaded probing, walking the list of drivers is done
+ * on a probing thread.
*
* Returns 1 if the device was bound to a driver;
- * 0 if no matching device was found; error code otherwise.
+ * 0 if no matching device was found or multithreaded probing is done;
+ * -ENODEV if the device is not registered.
*
* When called for a USB interface, @dev->parent->sem must be held.
*/
int device_attach(struct device * dev)
{
int ret = 0;
+ struct task_struct *probe_task = ERR_PTR(-ENOMEM);
down(&dev->sem);
if (dev->driver) {
ret = device_bind_driver(dev);
if (ret == 0)
ret = 1;
- } else
- ret = bus_for_each_drv(dev->bus, NULL, dev, __device_attach);
+ else {
+ dev->driver = NULL;
+ ret = 0;
+ }
+ } else {
+ if (dev->bus->multithread_probe)
+ probe_task = kthread_run(device_probe_drivers, dev,
+ "probe-%s", dev->bus_id);
+ if(IS_ERR(probe_task))
+ ret = bus_for_each_drv(dev->bus, NULL, dev,
+ __device_attach);
+ }
up(&dev->sem);
return ret;
}