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>

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 014a2eaa53899d40e1d1eb91f54ba3870e09e9f4..769a740c104c5c28eca38504eba3eded8a767758 100644 (file)
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -216,6 +216,7 @@ struct hci_dev {
        unsigned long   le_last_tx;
 
        struct workqueue_struct *workqueue;
+       struct workqueue_struct *req_workqueue;
 
        struct work_struct      power_on;
        struct delayed_work     power_off;

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 596660d37c5e56d6a0178b16b288a2d3c868f965..f73907aad79fffcf76ada1795008ddc221cf3de4 100644 (file)
--- 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);