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Diffstat (limited to 'net/nfc/nci/core.c')
-rw-r--r--net/nfc/nci/core.c19
1 files changed, 17 insertions, 2 deletions
diff --git a/net/nfc/nci/core.c b/net/nfc/nci/core.c
index 1dd0269c1a72..d2537383a3e8 100644
--- a/net/nfc/nci/core.c
+++ b/net/nfc/nci/core.c
@@ -476,6 +476,11 @@ static int nci_open_device(struct nci_dev *ndev)
mutex_lock(&ndev->req_lock);
+ if (test_bit(NCI_UNREG, &ndev->flags)) {
+ rc = -ENODEV;
+ goto done;
+ }
+
if (test_bit(NCI_UP, &ndev->flags)) {
rc = -EALREADY;
goto done;
@@ -548,6 +553,10 @@ done:
static int nci_close_device(struct nci_dev *ndev)
{
nci_req_cancel(ndev, ENODEV);
+
+ /* This mutex needs to be held as a barrier for
+ * caller nci_unregister_device
+ */
mutex_lock(&ndev->req_lock);
if (!test_and_clear_bit(NCI_UP, &ndev->flags)) {
@@ -585,8 +594,8 @@ static int nci_close_device(struct nci_dev *ndev)
del_timer_sync(&ndev->cmd_timer);
- /* Clear flags */
- ndev->flags = 0;
+ /* Clear flags except NCI_UNREG */
+ ndev->flags &= BIT(NCI_UNREG);
mutex_unlock(&ndev->req_lock);
@@ -1269,6 +1278,12 @@ void nci_unregister_device(struct nci_dev *ndev)
{
struct nci_conn_info *conn_info, *n;
+ /* This set_bit is not protected with specialized barrier,
+ * However, it is fine because the mutex_lock(&ndev->req_lock);
+ * in nci_close_device() will help to emit one.
+ */
+ set_bit(NCI_UNREG, &ndev->flags);
+
nci_close_device(ndev);
destroy_workqueue(ndev->cmd_wq);