NFC: Changed event_received hci ops result semantic

Some chips use a standard HCI event code, destined to a proprietary
gate, with a different meaning. Therefore, the HCI driver must always
have a chance to intercept the event before standard processing is
attempted.
The new semantic specifies that the result value "1" means that the
driver doesn't especially handle the event. result <= 0 means it was
handled.

Signed-off-by: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

2 files changed, 19 insertions, 11 deletions

diff --git a/drivers/nfc/pn544/pn544.c b/drivers/nfc/pn544/pn544.c
index 4af70f9c01aa..9349c548e8dc 100644
--- a/drivers/nfc/pn544/pn544.c
+++ b/drivers/nfc/pn544/pn544.c
@@ -714,18 +714,23 @@ static int pn544_hci_check_presence(struct nfc_hci_dev *hdev,
         return 0;
 }
 
+/*
+ * Returns:
+ * <= 0: driver handled the event, skb consumed
+ *    1: driver does not handle the event, please do standard processing
+ */
 static int pn544_hci_event_received(struct nfc_hci_dev *hdev, u8 gate, u8 event,
                                     struct sk_buff *skb)
 {
         struct sk_buff *rgb_skb = NULL;
-        int r = 0;
+        int r;
 
         pr_debug("hci event %d", event);
         switch (event) {
         case PN544_HCI_EVT_ACTIVATED:
-                if (gate == PN544_RF_READER_NFCIP1_INITIATOR_GATE)
+                if (gate == PN544_RF_READER_NFCIP1_INITIATOR_GATE) {
                         r = nfc_hci_target_discovered(hdev, gate);
-                else if (gate == PN544_RF_READER_NFCIP1_TARGET_GATE) {
+                } else if (gate == PN544_RF_READER_NFCIP1_TARGET_GATE) {
                         r = nfc_hci_get_param(hdev, gate, PN544_DEP_ATR_REQ,
                                               &rgb_skb);
                         if (r < 0)
@@ -736,6 +741,8 @@ static int pn544_hci_event_received(struct nfc_hci_dev *hdev, u8 gate, u8 event,
                                              rgb_skb->len);
 
                         kfree_skb(rgb_skb);
+                } else {
+                        r = -EINVAL;
                 }
                 break;
         case PN544_HCI_EVT_DEACTIVATED:
@@ -757,8 +764,7 @@ static int pn544_hci_event_received(struct nfc_hci_dev *hdev, u8 gate, u8 event,
                 skb_pull(skb, 2);
                 return nfc_tm_data_received(hdev->ndev, skb);
         default:
-                pr_err("Discarded unknown event %x to gate %x\n", event, gate);
-                break;
+                return 1;
         }
 
 exit:
diff --git a/net/nfc/hci/core.c b/net/nfc/hci/core.c
index f30f6fe815b4..0430f3086e41 100644
--- a/net/nfc/hci/core.c
+++ b/net/nfc/hci/core.c
@@ -297,6 +297,12 @@ void nfc_hci_event_received(struct nfc_hci_dev *hdev, u8 pipe, u8 event,
                 goto exit;
         }
 
+        if (hdev->ops->event_received) {
+                r = hdev->ops->event_received(hdev, gate, event, skb);
+                if (r <= 0)
+                        goto exit_noskb;
+        }
+
         switch (event) {
         case NFC_HCI_EVT_TARGET_DISCOVERED:
                 if (skb->len < 1) {     /* no status data? */
@@ -322,12 +328,8 @@ void nfc_hci_event_received(struct nfc_hci_dev *hdev, u8 pipe, u8 event,
                 r = nfc_hci_target_discovered(hdev, gate);
                 break;
         default:
-                if (hdev->ops->event_received) {
-                        r = hdev->ops->event_received(hdev, gate, event, skb);
-                        goto exit_noskb;
-                } else {
-                        r = -EINVAL;
-                }
+                pr_info("Discarded unknown event %x to gate %x\n", event, gate);
+                r = -EINVAL;
                 break;
         }