NFC: Check if NCI data flow control is used

Check if NCI data flow control is used in nci_tx_work.

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>

2 files changed, 7 insertions, 1 deletions

diff --git a/include/net/nfc/nci.h b/include/net/nfc/nci.h
index 0b34fde9b13..cdbe6713934 100644
--- a/include/net/nfc/nci.h
+++ b/include/net/nfc/nci.h
@@ -108,6 +108,9 @@
 /* NCI Static RF connection ID */
 #define NCI_STATIC_RF_CONN_ID                                   0x00
 
+/* NCI Data Flow Control */
+#define NCI_DATA_FLOW_CONTROL_NOT_USED                          0xff
+
 /* NCI RF_DISCOVER_MAP_CMD modes */
 #define NCI_DISC_MAP_MODE_POLL                                  0x01
 #define NCI_DISC_MAP_MODE_LISTEN                                0x02
diff --git a/net/nfc/nci/core.c b/net/nfc/nci/core.c
index 9d0b5305c36..3dffcb3221c 100644
--- a/net/nfc/nci/core.c
+++ b/net/nfc/nci/core.c
@@ -722,7 +722,10 @@ static void nci_tx_work(struct work_struct *work)
                 if (!skb)
                         return;
 
-                atomic_dec(&ndev->credits_cnt);
+                /* Check if data flow control is used */
+                if (atomic_read(&ndev->credits_cnt) !=
+                                NCI_DATA_FLOW_CONTROL_NOT_USED)
+                        atomic_dec(&ndev->credits_cnt);
 
                 nfc_dbg("NCI TX: MT=data, PBF=%d, conn_id=%d, plen=%d",
                                 nci_pbf(skb->data),