NFC: protect nci_data_exchange transactions
Protect 'cb' and 'cb_context' arguments in nci_data_exchange.
In fact, this implements a queue with max length of 1 data
exchange transactions in parallel.
Signed-off-by: Ilan Elias <ilane@ti.com>
Acked-by: Lauro Ramos Venancio <lauro.venancio@openbossa.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/nfc/nci/core.c b/net/nfc/nci/core.c
index 9f17e8e..1e6b20f 100644
--- a/net/nfc/nci/core.c
+++ b/net/nfc/nci/core.c
@@ -453,6 +453,7 @@
void *cb_context)
{
struct nci_dev *ndev = nfc_get_drvdata(nfc_dev);
+ int rc;
nfc_dbg("entry, target_idx %d, len %d", target_idx, skb->len);
@@ -461,11 +462,18 @@
return -EINVAL;
}
+ if (test_and_set_bit(NCI_DATA_EXCHANGE, &ndev->flags))
+ return -EBUSY;
+
/* store cb and context to be used on receiving data */
ndev->data_exchange_cb = cb;
ndev->data_exchange_cb_context = cb_context;
- return nci_send_data(ndev, ndev->conn_id, skb);
+ rc = nci_send_data(ndev, ndev->conn_id, skb);
+ if (rc)
+ clear_bit(NCI_DATA_EXCHANGE, &ndev->flags);
+
+ return rc;
}
static struct nfc_ops nci_nfc_ops = {
diff --git a/net/nfc/nci/data.c b/net/nfc/nci/data.c
index 141790a..e5ed90f 100644
--- a/net/nfc/nci/data.c
+++ b/net/nfc/nci/data.c
@@ -54,6 +54,8 @@
/* no waiting callback, free skb */
kfree_skb(skb);
}
+
+ clear_bit(NCI_DATA_EXCHANGE, &ndev->flags);
}
/* ----------------- NCI TX Data ----------------- */
diff --git a/net/nfc/nci/ntf.c b/net/nfc/nci/ntf.c
index 8dd7535..96633f5 100644
--- a/net/nfc/nci/ntf.c
+++ b/net/nfc/nci/ntf.c
@@ -215,7 +215,7 @@
}
/* complete the data exchange transaction, if exists */
- if (ndev->data_exchange_cb)
+ if (test_bit(NCI_DATA_EXCHANGE, &ndev->flags))
nci_data_exchange_complete(ndev, NULL, -EIO);
}