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-rw-r--r--drivers/base/dd.c108
-rw-r--r--include/linux/device.h3
-rw-r--r--init/do_mounts.c5
3 files changed, 89 insertions, 27 deletions
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 9f6f11c..319a73b 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -17,6 +17,7 @@
#include <linux/device.h>
#include <linux/module.h>
+#include <linux/kthread.h>
#include "base.h"
#include "power/power.h"
@@ -63,44 +64,35 @@ int device_bind_driver(struct device *dev)
return ret;
}
-/**
- * driver_probe_device - attempt to bind device & driver.
- * @drv: driver.
- * @dev: device.
- *
- * First, we call the bus's match function, if one present, which
- * should compare the device IDs the driver supports with the
- * device IDs of the device. Note we don't do this ourselves
- * because we don't know the 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 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 {
+ struct device_driver *drv;
+ struct device *dev;
+};
+
+static atomic_t probe_count = ATOMIC_INIT(0);
+static int really_probe(void *void_data)
{
+ struct stupid_thread_structure *data = void_data;
+ struct device_driver *drv = data->drv;
+ struct device *dev = data->dev;
int ret = 0;
- if (drv->bus->match && !drv->bus->match(dev, drv))
- goto Done;
+ atomic_inc(&probe_count);
+ pr_debug("%s: Probing driver %s with device %s\n",
+ drv->bus->name, drv->name, dev->bus_id);
- pr_debug("%s: Matched Device %s with Driver %s\n",
- drv->bus->name, dev->bus_id, drv->name);
dev->driver = drv;
if (dev->bus->probe) {
ret = dev->bus->probe(dev);
if (ret) {
dev->driver = NULL;
- goto ProbeFailed;
+ goto probe_failed;
}
} else if (drv->probe) {
ret = drv->probe(dev);
if (ret) {
dev->driver = NULL;
- goto ProbeFailed;
+ goto probe_failed;
}
}
if (device_bind_driver(dev)) {
@@ -111,9 +103,9 @@ int driver_probe_device(struct device_driver * drv, struct device * dev)
ret = 1;
pr_debug("%s: Bound Device %s to Driver %s\n",
drv->bus->name, dev->bus_id, drv->name);
- goto Done;
+ goto done;
- ProbeFailed:
+probe_failed:
if (ret == -ENODEV || ret == -ENXIO) {
/* Driver matched, but didn't support device
* or device not found.
@@ -126,7 +118,69 @@ int driver_probe_device(struct device_driver * drv, struct device * dev)
"%s: probe of %s failed with error %d\n",
drv->name, dev->bus_id, ret);
}
- Done:
+done:
+ kfree(data);
+ atomic_dec(&probe_count);
+ return ret;
+}
+
+/**
+ * driver_probe_done
+ * Determine if the probe sequence is finished or not.
+ *
+ * Should somehow figure out how to use a semaphore, not an atomic variable...
+ */
+int driver_probe_done(void)
+{
+ pr_debug("%s: probe_count = %d\n", __FUNCTION__,
+ atomic_read(&probe_count));
+ if (atomic_read(&probe_count))
+ return -EBUSY;
+ return 0;
+}
+
+/**
+ * driver_probe_device - attempt to bind device & driver together
+ * @drv: driver to bind a device to
+ * @dev: device to try to bind to the driver
+ *
+ * First, we call the bus's match function, if one present, which should
+ * compare the device IDs the driver supports with the device IDs of the
+ * device. Note we don't do this ourselves because we don't know the
+ * 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 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 (drv->bus->match && !drv->bus->match(dev, drv))
+ goto done;
+
+ pr_debug("%s: Matched Device %s with Driver %s\n",
+ drv->bus->name, dev->bus_id, drv->name);
+
+ data = kmalloc(sizeof(*data), GFP_KERNEL);
+ 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 = PTR_ERR(probe_task);
+ } else
+ ret = really_probe(data);
+
+done:
return ret;
}
diff --git a/include/linux/device.h b/include/linux/device.h
index b3da9a8..74246ef 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -106,6 +106,8 @@ struct device_driver {
void (*shutdown) (struct device * dev);
int (*suspend) (struct device * dev, pm_message_t state);
int (*resume) (struct device * dev);
+
+ unsigned int multithread_probe:1;
};
@@ -115,6 +117,7 @@ extern void driver_unregister(struct device_driver * drv);
extern struct device_driver * get_driver(struct device_driver * drv);
extern void put_driver(struct device_driver * drv);
extern struct device_driver *driver_find(const char *name, struct bus_type *bus);
+extern int driver_probe_done(void);
/* driverfs interface for exporting driver attributes */
diff --git a/init/do_mounts.c b/init/do_mounts.c
index 94aeec7..b290aad 100644
--- a/init/do_mounts.c
+++ b/init/do_mounts.c
@@ -8,6 +8,7 @@
#include <linux/security.h>
#include <linux/delay.h>
#include <linux/mount.h>
+#include <linux/device.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_fs_sb.h>
@@ -403,6 +404,10 @@ void __init prepare_namespace(void)
ssleep(root_delay);
}
+ /* wait for the known devices to complete their probing */
+ while (driver_probe_done() != 0)
+ msleep(100);
+
md_run_setup();
if (saved_root_name[0]) {
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