NFC: Prevent polling when device is down

Some devices turn radio on whenever they're asked to start a poll.
To prevent that from happening, we just don't call into the driver
start_poll hook when the NFC device is down.

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/net/nfc/core.c b/net/nfc/core.c
index 6ceee8e181ca..c571ca9a960c 100644
--- a/net/nfc/core.c
+++ b/net/nfc/core.c
@@ -143,6 +143,11 @@ int nfc_start_poll(struct nfc_dev *dev, u32 im_protocols, u32 tm_protocols)
                 goto error;
         }
 
+        if (!dev->dev_up) {
+                rc = -ENODEV;
+                goto error;
+        }
+
         if (dev->polling) {
                 rc = -EBUSY;
                 goto error;