3 files changed, 89 insertions, 27 deletions

diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 9f6f11ca0ab6..319a73be4180 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 b3da9a870cfc..74246efba931 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 94aeec7aa917..b290aadb1d3f 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]) {