When buffers on the receiption path exceed 262 bytes, the pn533 uses
a chaining mechanism where the initiator has to send NULL data frames
to fetch the remaining frames.
We do that from a workqueue context while holding the cmd lock. Once the
MI bit is gone, we aggregate the queued received skbs.
Signed-off-by: Samuel Ortiz <sameo@xxxxxxxxxxxxxxx>
---
drivers/nfc/pn533.c | 144 +++++++++++++++++++++++++++++++++++++++++++++------
1 files changed, 128 insertions(+), 16 deletions(-)
diff --git a/drivers/nfc/pn533.c b/drivers/nfc/pn533.c
index f2ee06f..e6ec16d 100644
--- a/drivers/nfc/pn533.c
+++ b/drivers/nfc/pn533.c
@@ -266,8 +266,11 @@ struct pn533 {
int in_maxlen;
struct pn533_frame *in_frame;
+ struct sk_buff_head resp_q;
+
struct workqueue_struct *wq;
struct work_struct cmd_work;
+ struct work_struct mi_work;
struct pn533_frame *wq_in_frame;
int wq_in_error;
@@ -1256,6 +1259,8 @@ static void pn533_deactivate_target(struct nfc_dev *nfc_dev, u32 target_idx)
dev->tgt_active_prot = 0;
+ skb_queue_purge(&dev->resp_q);
+
pn533_tx_frame_init(dev->out_frame, PN533_CMD_IN_RELEASE);
tg = 1;
@@ -1454,11 +1459,49 @@ struct pn533_data_exchange_arg {
void *cb_context;
};
+static struct sk_buff *pn533_build_response(struct pn533 *dev)
+{
+ struct sk_buff *skb, *tmp, *t;
+ unsigned int skb_len = 0, tmp_len = 0;
+
+ nfc_dev_dbg(&dev->interface->dev, "%s\n", __func__);
+
+ if (skb_queue_empty(&dev->resp_q))
+ return NULL;
+
+ if (skb_queue_len(&dev->resp_q) == 1) {
+ skb = skb_dequeue(&dev->resp_q);
+ goto out;
+ }
+
+ skb_queue_walk_safe(&dev->resp_q, tmp, t)
+ skb_len += tmp->len;
+
+ nfc_dev_dbg(&dev->interface->dev, "%s total length %d\n",
+ __func__, skb_len);
+
+ skb = alloc_skb(skb_len, GFP_KERNEL);
+ if (skb == NULL)
+ goto out;
+
+ skb_put(skb, skb_len);
+
+ skb_queue_walk_safe(&dev->resp_q, tmp, t) {
+ memcpy(skb->data + tmp_len, tmp->data, tmp->len);
+ tmp_len += tmp->len;
+ }
+
+out:
+ skb_queue_purge(&dev->resp_q);
+
+ return skb;
+}
+
static int pn533_data_exchange_complete(struct pn533 *dev, void *_arg,
u8 *params, int params_len)
{
struct pn533_data_exchange_arg *arg = _arg;
- struct sk_buff *skb_resp = arg->skb_resp;
+ struct sk_buff *skb = NULL, *skb_resp = arg->skb_resp;
struct pn533_frame *in_frame = (struct pn533_frame *) skb_resp->data;
int err = 0;
u8 status;
@@ -1466,15 +1509,13 @@ static int pn533_data_exchange_complete(struct pn533 *dev, void *_arg,
nfc_dev_dbg(&dev->interface->dev, "%s", __func__);
- dev_kfree_skb_irq(arg->skb_out);
+ dev_kfree_skb(arg->skb_out);
if (params_len < 0) { /* error */
err = params_len;
goto error;
}
- skb_put(skb_resp, PN533_FRAME_SIZE(in_frame));
-
status = params[0];
cmd_ret = status & PN533_CMD_RET_MASK;
@@ -1485,25 +1526,27 @@ static int pn533_data_exchange_complete(struct pn533 *dev, void *_arg,
goto error;
}
+ skb_put(skb_resp, PN533_FRAME_SIZE(in_frame));
+ skb_pull(skb_resp, PN533_CMD_DATAEXCH_HEAD_LEN);
+ skb_trim(skb_resp, skb_resp->len - PN533_FRAME_TAIL_SIZE);
+ skb_queue_tail(&dev->resp_q, skb_resp);
+
if (status & PN533_CMD_MI_MASK) {
- /* TODO: Implement support to multi-part data exchange */
- nfc_dev_err(&dev->interface->dev, "Multi-part message not yet"
- " supported");
- /* Prevent the other messages from controller */
- pn533_send_ack(dev, GFP_ATOMIC);
- err = -ENOSYS;
- goto error;
+ queue_work(dev->wq, &dev->mi_work);
+ return -EINPROGRESS;
}
- skb_pull(skb_resp, PN533_CMD_DATAEXCH_HEAD_LEN);
- skb_trim(skb_resp, skb_resp->len - PN533_FRAME_TAIL_SIZE);
+ skb = pn533_build_response(dev);
+ if (skb == NULL)
+ goto error;
- arg->cb(arg->cb_context, skb_resp, 0);
+ arg->cb(arg->cb_context, skb, 0);
kfree(arg);
return 0;
error:
- dev_kfree_skb_irq(skb_resp);
+ skb_queue_purge(&dev->resp_q);
+ dev_kfree_skb(skb_resp);
arg->cb(arg->cb_context, NULL, err);
kfree(arg);
return 0;
@@ -1578,6 +1621,68 @@ error:
return rc;
}
+static void pn533_wq_mi_recv(struct work_struct *work)
+{
+ struct pn533 *dev = container_of(work, struct pn533, mi_work);
+ struct sk_buff *skb_cmd;
+ struct pn533_data_exchange_arg *arg = dev->cmd_complete_arg;
+ struct pn533_frame *out_frame, *in_frame;
+ struct sk_buff *skb_resp;
+ int skb_resp_len;
+ int rc;
+
+ nfc_dev_dbg(&dev->interface->dev, "%s", __func__);
+
+ /* This is a zero payload size skb */
+ skb_cmd = alloc_skb(PN533_CMD_DATAEXCH_HEAD_LEN + PN533_FRAME_TAIL_SIZE,
+ GFP_KERNEL);
+ if (skb_cmd == NULL)
+ goto error_cmd;
+
+ skb_reserve(skb_cmd, PN533_CMD_DATAEXCH_HEAD_LEN);
+
+ rc = pn533_data_exchange_tx_frame(dev, skb_cmd);
+ if (rc)
+ goto error_frame;
+
+ skb_resp_len = PN533_CMD_DATAEXCH_HEAD_LEN +
+ PN533_CMD_DATAEXCH_DATA_MAXLEN +
+ PN533_FRAME_TAIL_SIZE;
+ skb_resp = alloc_skb(skb_resp_len, GFP_KERNEL);
+ if (!skb_resp) {
+ rc = -ENOMEM;
+ goto error_frame;
+ }
+
+ in_frame = (struct pn533_frame *) skb_resp->data;
+ out_frame = (struct pn533_frame *) skb_cmd->data;
+
+ arg->skb_resp = skb_resp;
+ arg->skb_out = skb_cmd;
+
+ rc = __pn533_send_cmd_frame_async(dev, out_frame, in_frame,
+ skb_resp_len,
+ pn533_data_exchange_complete,
+ dev->cmd_complete_arg, GFP_KERNEL);
+ if (!rc)
+ return;
+
+ nfc_dev_err(&dev->interface->dev, "Error %d when trying to"
+ " perform data_exchange", rc);
+
+ kfree_skb(skb_resp);
+
+error_frame:
+ kfree_skb(skb_cmd);
+
+error_cmd:
+ pn533_send_ack(dev, GFP_KERNEL);
+
+ kfree(arg);
+
+ up(&dev->cmd_lock);
+}
+
static int pn533_set_configuration(struct pn533 *dev, u8 cfgitem, u8 *cfgdata,
u8 cfgdata_len)
{
@@ -1676,10 +1781,15 @@ static int pn533_probe(struct usb_interface *interface,
pn533_send_complete, dev);
INIT_WORK(&dev->cmd_work, pn533_wq_cmd_complete);
- dev->wq = create_singlethread_workqueue("pn533");
+ INIT_WORK(&dev->mi_work, pn533_wq_mi_recv);
+ dev->wq = alloc_workqueue("pn533",
+ WQ_NON_REENTRANT | WQ_UNBOUND | WQ_MEM_RECLAIM,
+ 1);
if (dev->wq == NULL)
goto error;
+ skb_queue_head_init(&dev->resp_q);
+
usb_set_intfdata(interface, dev);
pn533_tx_frame_init(dev->out_frame, PN533_CMD_GET_FIRMWARE_VERSION);
@@ -1756,6 +1866,8 @@ static void pn533_disconnect(struct usb_interface *interface)
destroy_workqueue(dev->wq);
+ skb_queue_purge(&dev->resp_q);
+
kfree(dev->in_frame);
usb_free_urb(dev->in_urb);
kfree(dev->out_frame);
--
1.7.9.1
--
To unsubscribe from this list: send the line "unsubscribe linux-wireless" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
