NFC: pn533: Add pn533_abort_cmd procedure
pn533_abort_cmd() aborts last command sent to the controller
and cancels already requested urb.
As ACR122U does not support any mechanism (as ACK for standard
PN533) which aborts last command this cannot be issued for this
device. Otherwise, acr122u will behave in an unstable way.
Signed-off-by: Waldemar Rymarkiewicz <waldemar.rymarkiewicz@tieto.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/nfc/pn533.c b/drivers/nfc/pn533.c
index 697f154..22efb6a 100644
--- a/drivers/nfc/pn533.c
+++ b/drivers/nfc/pn533.c
@@ -1113,6 +1113,23 @@
}
}
+static void pn533_abort_cmd(struct pn533 *dev, gfp_t flags)
+{
+ /* ACR122U does not support any command which aborts last
+ * issued command i.e. as ACK for standard PN533. Additionally,
+ * it behaves stange, sending broken or incorrect responses,
+ * when we cancel urb before the chip will send response.
+ */
+ if (dev->device_type == PN533_DEVICE_ACR122U)
+ return;
+
+ /* An ack will cancel the last issued command */
+ pn533_send_ack(dev, flags);
+
+ /* cancel the urb request */
+ usb_kill_urb(dev->in_urb);
+}
+
static struct sk_buff *pn533_alloc_skb(struct pn533 *dev, unsigned int size)
{
struct sk_buff *skb;
@@ -1631,9 +1648,6 @@
nfc_dev_dbg(&dev->interface->dev, "Listen mode timeout");
- /* An ack will cancel the last issued command (poll) */
- pn533_send_ack(dev, GFP_ATOMIC);
-
dev->cancel_listen = 1;
pn533_poll_next_mod(dev);
@@ -1763,7 +1777,7 @@
if (dev->cancel_listen == 1) {
dev->cancel_listen = 0;
- usb_kill_urb(dev->in_urb);
+ pn533_abort_cmd(dev, GFP_ATOMIC);
}
rc = pn533_send_poll_frame(dev);
@@ -1825,12 +1839,7 @@
return;
}
- /* An ack will cancel the last issued command (poll) */
- pn533_send_ack(dev, GFP_KERNEL);
-
- /* prevent pn533_start_poll_complete to issue a new poll meanwhile */
- usb_kill_urb(dev->in_urb);
-
+ pn533_abort_cmd(dev, GFP_KERNEL);
pn533_poll_reset_mod_list(dev);
}
@@ -2123,10 +2132,8 @@
pn533_poll_reset_mod_list(dev);
- if (dev->tgt_mode || dev->tgt_active_prot) {
- pn533_send_ack(dev, GFP_KERNEL);
- usb_kill_urb(dev->in_urb);
- }
+ if (dev->tgt_mode || dev->tgt_active_prot)
+ pn533_abort_cmd(dev, GFP_KERNEL);
dev->tgt_active_prot = 0;
dev->tgt_mode = 0;
