firewire: core: fix sleep in atomic context due to driver core change

Due to commit 2831fe6f9cc4e16c103504ee09a47a084297c0f3, "driver core:
create a private portion of struct device", device_initialize() can no
longer be called from atomic contexts.

We now defer it until after config ROM probing.  This requires changes
to the bus manager code because this may use a device before it was
probed.

Reported-by: Jay Fenlason <fenlason@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

1 files changed, 13 insertions, 10 deletions

diff --git a/drivers/firewire/fw-device.c b/drivers/firewire/fw-device.c
index c173be383725..2af5a8d1e012 100644
--- a/drivers/firewire/fw-device.c
+++ b/drivers/firewire/fw-device.c
@@ -159,7 +159,8 @@ static void fw_device_release(struct device *dev)
 
         /*
          * Take the card lock so we don't set this to NULL while a
-         * FW_NODE_UPDATED callback is being handled.
+         * FW_NODE_UPDATED callback is being handled or while the
+         * bus manager work looks at this node.
          */
         spin_lock_irqsave(&card->lock, flags);
         device->node->data = NULL;
@@ -695,12 +696,13 @@ static void fw_device_init(struct work_struct *work)
                 return;
         }
 
-        err = -ENOMEM;
+        device_initialize(&device->device);
 
         fw_device_get(device);
         down_write(&fw_device_rwsem);
-        if (idr_pre_get(&fw_device_idr, GFP_KERNEL))
-                err = idr_get_new(&fw_device_idr, device, &minor);
+        err = idr_pre_get(&fw_device_idr, GFP_KERNEL) ?
+              idr_get_new(&fw_device_idr, device, &minor) :
+              -ENOMEM;
         up_write(&fw_device_rwsem);
 
         if (err < 0)
@@ -911,13 +913,14 @@ void fw_node_event(struct fw_card *card, struct fw_node *node, int event)
 
                 /*
                  * Do minimal intialization of the device here, the
-                 * rest will happen in fw_device_init().  We need the
-                 * card and node so we can read the config rom and we
-                 * need to do device_initialize() now so
-                 * device_for_each_child() in FW_NODE_UPDATED is
-                 * doesn't freak out.
+                 * rest will happen in fw_device_init().
+                 *
+                 * Attention:  A lot of things, even fw_device_get(),
+                 * cannot be done before fw_device_init() finished!
+                 * You can basically just check device->state and
+                 * schedule work until then, but only while holding
+                 * card->lock.
                  */
-                device_initialize(&device->device);
                 atomic_set(&device->state, FW_DEVICE_INITIALIZING);
                 device->card = fw_card_get(card);
                 device->node = fw_node_get(node);