diff options
Diffstat (limited to 'net/nfc/nci/core.c')
| -rw-r--r-- | net/nfc/nci/core.c | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/net/nfc/nci/core.c b/net/nfc/nci/core.c index 39994dbb6a55..e41e2e9e5498 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); @@ -1273,6 +1282,12 @@ 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); |