Bluetooth: Add a new workqueue for hci_request operations

The hci_request function is blocking and cannot be called through the
usual per-HCI device workqueue (hdev->workqueue). While hci_request is
in progress any other work from the queue, including sending HCI
commands to the controller would be blocked and eventually cause the
hci_request call to time out.

This patch adds a second workqueue to be used by operations needing
hci_request and thereby avoiding issues with blocking other workqueue
users.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>

1 files changed, 11 insertions, 0 deletions

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 596660d37c5e..f73907aad79f 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -1799,6 +1799,15 @@ int hci_register_dev(struct hci_dev *hdev)
                 goto err;
         }
 
+        hdev->req_workqueue = alloc_workqueue(hdev->name,
+                                              WQ_HIGHPRI | WQ_UNBOUND |
+                                              WQ_MEM_RECLAIM, 1);
+        if (!hdev->req_workqueue) {
+                destroy_workqueue(hdev->workqueue);
+                error = -ENOMEM;
+                goto err;
+        }
+
         error = hci_add_sysfs(hdev);
         if (error < 0)
                 goto err_wqueue;
@@ -1827,6 +1836,7 @@ int hci_register_dev(struct hci_dev *hdev)
 
 err_wqueue:
         destroy_workqueue(hdev->workqueue);
+        destroy_workqueue(hdev->req_workqueue);
 err:
         ida_simple_remove(&hci_index_ida, hdev->id);
         write_lock(&hci_dev_list_lock);
@@ -1880,6 +1890,7 @@ void hci_unregister_dev(struct hci_dev *hdev)
         hci_del_sysfs(hdev);
 
         destroy_workqueue(hdev->workqueue);
+        destroy_workqueue(hdev->req_workqueue);
 
         hci_dev_lock(hdev);
         hci_blacklist_clear(hdev);