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>

diff --git a/net/nfc/core.c b/net/nfc/core.c
index 6ceee8e..c571ca9 100644 (file)
--- 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;