NFC: HCI check presence must not fail when driver doesn't support it

When the driver does not support checking the tag is still present, it
must return -EOPNOTSUPP. The NFC Core will then stop asking and not
report a tag lost event to user space.

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

2 files changed, 4 insertions, 1 deletions

diff --git a/drivers/nfc/pn544_hci.c b/drivers/nfc/pn544_hci.c
index b66d4681a577..70858b5f81e4 100644
--- a/drivers/nfc/pn544_hci.c
+++ b/drivers/nfc/pn544_hci.c
@@ -986,7 +986,7 @@ static int pn544_hci_check_presence(struct nfc_hci_dev *hdev,
         } else if (target->supported_protocols & NFC_PROTO_MIFARE_MASK) {
                 if (target->nfcid1_len != 4 && target->nfcid1_len != 7 &&
                     target->nfcid1_len != 10)
-                        return -EPROTO;
+                        return -EOPNOTSUPP;
 
                  return nfc_hci_send_cmd(hdev, NFC_HCI_RF_READER_A_GATE,
                                      PN544_RF_READER_CMD_ACTIVATE_NEXT,
diff --git a/net/nfc/core.c b/net/nfc/core.c
index 479bee36dc3e..4cb069766ce5 100644
--- a/net/nfc/core.c
+++ b/net/nfc/core.c
@@ -697,6 +697,8 @@ static void nfc_check_pres_work(struct work_struct *work)
 
         if (dev->active_target && timer_pending(&dev->check_pres_timer) == 0) {
                 rc = dev->ops->check_presence(dev, dev->active_target);
+                if (rc == -EOPNOTSUPP)
+                        goto exit;
                 if (!rc) {
                         mod_timer(&dev->check_pres_timer, jiffies +
                                   msecs_to_jiffies(NFC_CHECK_PRES_FREQ_MS));
@@ -708,6 +710,7 @@ static void nfc_check_pres_work(struct work_struct *work)
                 }
         }
 
+exit:
         device_unlock(&dev->dev);
 }