Merge tag 'nfc-next-4.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/sameo/nfc-next

Samuel Ortiz says:

====================
NFC 4.8 pull request

This is the first NFC pull request for 4.8. We have:

- A fairly large NFC digital stack patchset:
* RTOX fixes.
* Proper DEP RWT support.
* ACK and NACK PDUs handling fixes, in both initiator
and target modes.
* A few memory leak fixes.

- A conversion of the nfcsim driver to use the digital stack.
The driver supports the DEP protocol in both NFC-A and NFC-F.

- Error injection through debugfs for the nfcsim driver.

- Improvements to the port100 driver for the Sony USB chipset, in
particular to the command abort and cancellation code paths.

- A few minor fixes for the pn533, trf7970a and fdp drivers.
====================

Signed-off-by: David S. Miller <[e-mail]>

drivers/nfc/Kconfig

···
 
 config NFC_SIM
 	tristate "NFC hardware simulator driver"
+	depends on NFC_DIGITAL
 	help
 	  This driver declares two virtual NFC devices supporting NFC-DEP
 	  protocol. An LLCP connection can be established between them and

drivers/nfc/fdp/fdp.c

···
 
 	if (info->ram_patch) {
 		release_firmware(info->ram_patch);
-		info->otp_patch = NULL;
+		info->ram_patch = NULL;
 	}
 }
 
···
 {
 	struct fdp_nci_info *info = nci_get_drvdata(ndev);
 	struct device *dev = &info->phy->i2c_dev->dev;
-	u8 conn_id;
+	int conn_id;
 	int r = 0;
 
 	if (info->otp_version >= info->otp_patch_version)
···
 {
 	struct fdp_nci_info *info = nci_get_drvdata(ndev);
 	struct device *dev = &info->phy->i2c_dev->dev;
-	u8 conn_id;
+	int conn_id;
 	int r = 0;
 
 	if (info->ram_version >= info->ram_patch_version)

drivers/nfc/nfcsim.c

···
 #include <linux/device.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/ctype.h>
+#include <linux/debugfs.h>
 #include <linux/nfc.h>
 #include <net/nfc/nfc.h>
+#include <net/nfc/digital.h>
 
-#define DEV_ERR(_dev, fmt, args...) nfc_err(&_dev->nfc_dev->dev, \
-						"%s: " fmt, __func__, ## args)
+#define NFCSIM_ERR(d, fmt, args...) nfc_err(&d->nfc_digital_dev->nfc_dev->dev, \
+					    "%s: " fmt, __func__, ## args)
 
-#define DEV_DBG(_dev, fmt, args...) dev_dbg(&_dev->nfc_dev->dev, \
-						"%s: " fmt, __func__, ## args)
+#define NFCSIM_DBG(d, fmt, args...) dev_dbg(&d->nfc_digital_dev->nfc_dev->dev, \
+					    "%s: " fmt, __func__, ## args)
 
-#define NFCSIM_VERSION "0.1"
+#define NFCSIM_VERSION "0.2"
 
-#define NFCSIM_POLL_NONE	0
-#define NFCSIM_POLL_INITIATOR	1
-#define NFCSIM_POLL_TARGET	2
-#define NFCSIM_POLL_DUAL	(NFCSIM_POLL_INITIATOR | NFCSIM_POLL_TARGET)
+#define NFCSIM_MODE_NONE	0
+#define NFCSIM_MODE_INITIATOR	1
+#define NFCSIM_MODE_TARGET	2
 
-#define RX_DEFAULT_DELAY	5
+#define NFCSIM_CAPABILITIES (NFC_DIGITAL_DRV_CAPS_IN_CRC   | \
+			     NFC_DIGITAL_DRV_CAPS_TG_CRC)
 
 struct nfcsim {
-	struct nfc_dev *nfc_dev;
+	struct nfc_digital_dev *nfc_digital_dev;
 
+	struct work_struct recv_work;
+	struct delayed_work send_work;
+
+	struct nfcsim_link *link_in;
+	struct nfcsim_link *link_out;
+
+	bool up;
+	u8 mode;
+	u8 rf_tech;
+
+	u16 recv_timeout;
+
+	nfc_digital_cmd_complete_t cb;
+	void *arg;
+
+	u8 dropframe;
+};
+
+struct nfcsim_link {
 	struct mutex lock;
 
-	struct delayed_work recv_work;
+	u8 rf_tech;
+	u8 mode;
 
-	struct sk_buff *clone_skb;
+	u8 shutdown;
 
-	struct delayed_work poll_work;
-	u8 polling_mode;
-	u8 curr_polling_mode;
-
-	u8 shutting_down;
-
-	u8 up;
-
-	u8 initiator;
-
-	u32 rx_delay;
-
-	data_exchange_cb_t cb;
-	void *cb_context;
-
-	struct nfcsim *peer_dev;
+	struct sk_buff *skb;
+	wait_queue_head_t recv_wait;
+	u8 cond;
 };
+
+static struct nfcsim_link *nfcsim_link_new(void)
+{
+	struct nfcsim_link *link;
+
+	link = kzalloc(sizeof(struct nfcsim_link), GFP_KERNEL);
+	if (!link)
+		return NULL;
+
+	mutex_init(&link->lock);
+	init_waitqueue_head(&link->recv_wait);
+
+	return link;
+}
+
+static void nfcsim_link_free(struct nfcsim_link *link)
+{
+	dev_kfree_skb(link->skb);
+	kfree(link);
+}
+
+static void nfcsim_link_recv_wake(struct nfcsim_link *link)
+{
+	link->cond = 1;
+	wake_up_interruptible(&link->recv_wait);
+}
+
+static void nfcsim_link_set_skb(struct nfcsim_link *link, struct sk_buff *skb,
+				u8 rf_tech, u8 mode)
+{
+	mutex_lock(&link->lock);
+
+	dev_kfree_skb(link->skb);
+	link->skb = skb;
+	link->rf_tech = rf_tech;
+	link->mode = mode;
+
+	mutex_unlock(&link->lock);
+}
+
+static void nfcsim_link_recv_cancel(struct nfcsim_link *link)
+{
+	mutex_lock(&link->lock);
+
+	link->mode = NFCSIM_MODE_NONE;
+
+	mutex_unlock(&link->lock);
+
+	nfcsim_link_recv_wake(link);
+}
+
+static void nfcsim_link_shutdown(struct nfcsim_link *link)
+{
+	mutex_lock(&link->lock);
+
+	link->shutdown = 1;
+	link->mode = NFCSIM_MODE_NONE;
+
+	mutex_unlock(&link->lock);
+
+	nfcsim_link_recv_wake(link);
+}
+
+static struct sk_buff *nfcsim_link_recv_skb(struct nfcsim_link *link,
+					    int timeout, u8 rf_tech, u8 mode)
+{
+	int rc;
+	struct sk_buff *skb;
+
+	rc = wait_event_interruptible_timeout(link->recv_wait,
+					      link->cond,
+					      msecs_to_jiffies(timeout));
+
+	mutex_lock(&link->lock);
+
+	skb = link->skb;
+	link->skb = NULL;
+
+	if (!rc) {
+		rc = -ETIMEDOUT;
+		goto done;
+	}
+
+	if (!skb || link->rf_tech != rf_tech || link->mode == mode) {
+		rc = -EINVAL;
+		goto done;
+	}
+
+	if (link->shutdown) {
+		rc = -ENODEV;
+		goto done;
+	}
+
+done:
+	mutex_unlock(&link->lock);
+
+	if (rc < 0) {
+		dev_kfree_skb(skb);
+		skb = ERR_PTR(rc);
+	}
+
+	link->cond = 0;
+
+	return skb;
+}
+
+static void nfcsim_send_wq(struct work_struct *work)
+{
+	struct nfcsim *dev = container_of(work, struct nfcsim, send_work.work);
+
+	/*
+	 * To effectively send data, the device just wake up its link_out which
+	 * is the link_in of the peer device. The exchanged skb has already been
+	 * stored in the dev->link_out through nfcsim_link_set_skb().
+	 */
+	nfcsim_link_recv_wake(dev->link_out);
+}
+
+static void nfcsim_recv_wq(struct work_struct *work)
+{
+	struct nfcsim *dev = container_of(work, struct nfcsim, recv_work);
+	struct sk_buff *skb;
+
+	skb = nfcsim_link_recv_skb(dev->link_in, dev->recv_timeout,
+				   dev->rf_tech, dev->mode);
+
+	if (!dev->up) {
+		NFCSIM_ERR(dev, "Device is down\n");
+
+		if (!IS_ERR(skb))
+			dev_kfree_skb(skb);
+
+		skb = ERR_PTR(-ENODEV);
+	}
+
+	dev->cb(dev->nfc_digital_dev, dev->arg, skb);
+}
+
+static int nfcsim_send(struct nfc_digital_dev *ddev, struct sk_buff *skb,
+		       u16 timeout, nfc_digital_cmd_complete_t cb, void *arg)
+{
+	struct nfcsim *dev = nfc_digital_get_drvdata(ddev);
+	u8 delay;
+
+	if (!dev->up) {
+		NFCSIM_ERR(dev, "Device is down\n");
+		return -ENODEV;
+	}
+
+	dev->recv_timeout = timeout;
+	dev->cb = cb;
+	dev->arg = arg;
+
+	schedule_work(&dev->recv_work);
+
+	if (dev->dropframe) {
+		NFCSIM_DBG(dev, "dropping frame (out of %d)\n", dev->dropframe);
+		dev_kfree_skb(skb);
+		dev->dropframe--;
+
+		return 0;
+	}
+
+	if (skb) {
+		nfcsim_link_set_skb(dev->link_out, skb, dev->rf_tech,
+				    dev->mode);
+
+		/* Add random delay (between 3 and 10 ms) before sending data */
+		get_random_bytes(&delay, 1);
+		delay = 3 + (delay & 0x07);
+
+		schedule_delayed_work(&dev->send_work, msecs_to_jiffies(delay));
+	}
+
+	return 0;
+}
+
+static void nfcsim_abort_cmd(struct nfc_digital_dev *ddev)
+{
+	struct nfcsim *dev = nfc_digital_get_drvdata(ddev);
+
+	nfcsim_link_recv_cancel(dev->link_in);
+}
+
+static int nfcsim_switch_rf(struct nfc_digital_dev *ddev, bool on)
+{
+	struct nfcsim *dev = nfc_digital_get_drvdata(ddev);
+
+	dev->up = on;
+
+	return 0;
+}
+
+static int nfcsim_in_configure_hw(struct nfc_digital_dev *ddev,
+					  int type, int param)
+{
+	struct nfcsim *dev = nfc_digital_get_drvdata(ddev);
+
+	switch (type) {
+	case NFC_DIGITAL_CONFIG_RF_TECH:
+		dev->up = true;
+		dev->mode = NFCSIM_MODE_INITIATOR;
+		dev->rf_tech = param;
+		break;
+
+	case NFC_DIGITAL_CONFIG_FRAMING:
+		break;
+
+	default:
+		NFCSIM_ERR(dev, "Invalid configuration type: %d\n", type);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int nfcsim_in_send_cmd(struct nfc_digital_dev *ddev,
+			       struct sk_buff *skb, u16 timeout,
+			       nfc_digital_cmd_complete_t cb, void *arg)
+{
+	return nfcsim_send(ddev, skb, timeout, cb, arg);
+}
+
+static int nfcsim_tg_configure_hw(struct nfc_digital_dev *ddev,
+					  int type, int param)
+{
+	struct nfcsim *dev = nfc_digital_get_drvdata(ddev);
+
+	switch (type) {
+	case NFC_DIGITAL_CONFIG_RF_TECH:
+		dev->up = true;
+		dev->mode = NFCSIM_MODE_TARGET;
+		dev->rf_tech = param;
+		break;
+
+	case NFC_DIGITAL_CONFIG_FRAMING:
+		break;
+
+	default:
+		NFCSIM_ERR(dev, "Invalid configuration type: %d\n", type);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int nfcsim_tg_send_cmd(struct nfc_digital_dev *ddev,
+			       struct sk_buff *skb, u16 timeout,
+			       nfc_digital_cmd_complete_t cb, void *arg)
+{
+	return nfcsim_send(ddev, skb, timeout, cb, arg);
+}
+
+static int nfcsim_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
+			    nfc_digital_cmd_complete_t cb, void *arg)
+{
+	return nfcsim_send(ddev, NULL, timeout, cb, arg);
+}
+
+static struct nfc_digital_ops nfcsim_digital_ops = {
+	.in_configure_hw = nfcsim_in_configure_hw,
+	.in_send_cmd = nfcsim_in_send_cmd,
+
+	.tg_listen = nfcsim_tg_listen,
+	.tg_configure_hw = nfcsim_tg_configure_hw,
+	.tg_send_cmd = nfcsim_tg_send_cmd,
+
+	.abort_cmd = nfcsim_abort_cmd,
+	.switch_rf = nfcsim_switch_rf,
+};
+
+static struct dentry *nfcsim_debugfs_root;
+
+static void nfcsim_debugfs_init(void)
+{
+	nfcsim_debugfs_root = debugfs_create_dir("nfcsim", NULL);
+
+	if (!nfcsim_debugfs_root)
+		pr_err("Could not create debugfs entry\n");
+
+}
+
+static void nfcsim_debugfs_remove(void)
+{
+	debugfs_remove_recursive(nfcsim_debugfs_root);
+}
+
+static void nfcsim_debugfs_init_dev(struct nfcsim *dev)
+{
+	struct dentry *dev_dir;
+	char devname[5]; /* nfcX\0 */
+	u32 idx;
+	int n;
+
+	if (!nfcsim_debugfs_root) {
+		NFCSIM_ERR(dev, "nfcsim debugfs not initialized\n");
+		return;
+	}
+
+	idx = dev->nfc_digital_dev->nfc_dev->idx;
+	n = snprintf(devname, sizeof(devname), "nfc%d", idx);
+	if (n >= sizeof(devname)) {
+		NFCSIM_ERR(dev, "Could not compute dev name for dev %d\n", idx);
+		return;
+	}
+
+	dev_dir = debugfs_create_dir(devname, nfcsim_debugfs_root);
+	if (!dev_dir) {
+		NFCSIM_ERR(dev, "Could not create debugfs entries for nfc%d\n",
+			   idx);
+		return;
+	}
+
+	debugfs_create_u8("dropframe", 0664, dev_dir, &dev->dropframe);
+}
+
+static struct nfcsim *nfcsim_device_new(struct nfcsim_link *link_in,
+					struct nfcsim_link *link_out)
+{
+	struct nfcsim *dev;
+	int rc;
+
+	dev = kzalloc(sizeof(struct nfcsim), GFP_KERNEL);
+	if (!dev)
+		return ERR_PTR(-ENOMEM);
+
+	INIT_DELAYED_WORK(&dev->send_work, nfcsim_send_wq);
+	INIT_WORK(&dev->recv_work, nfcsim_recv_wq);
+
+	dev->nfc_digital_dev =
+			nfc_digital_allocate_device(&nfcsim_digital_ops,
+						    NFC_PROTO_NFC_DEP_MASK,
+						    NFCSIM_CAPABILITIES,
+						    0, 0);
+	if (!dev->nfc_digital_dev) {
+		kfree(dev);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	nfc_digital_set_drvdata(dev->nfc_digital_dev, dev);
+
+	dev->link_in = link_in;
+	dev->link_out = link_out;
+
+	rc = nfc_digital_register_device(dev->nfc_digital_dev);
+	if (rc) {
+		pr_err("Could not register digital device (%d)\n", rc);
+		nfc_digital_free_device(dev->nfc_digital_dev);
+		kfree(dev);
+
+		return ERR_PTR(rc);
+	}
+
+	nfcsim_debugfs_init_dev(dev);
+
+	return dev;
+}
+
+static void nfcsim_device_free(struct nfcsim *dev)
+{
+	nfc_digital_unregister_device(dev->nfc_digital_dev);
+
+	dev->up = false;
+
+	nfcsim_link_shutdown(dev->link_in);
+
+	cancel_delayed_work_sync(&dev->send_work);
+	cancel_work_sync(&dev->recv_work);
+
+	nfc_digital_free_device(dev->nfc_digital_dev);
+
+	kfree(dev);
+}
 
 static struct nfcsim *dev0;
 static struct nfcsim *dev1;
 
-static struct workqueue_struct *wq;
-
-static void nfcsim_cleanup_dev(struct nfcsim *dev, u8 shutdown)
-{
-	DEV_DBG(dev, "shutdown=%d\n", shutdown);
-
-	mutex_lock(&dev->lock);
-
-	dev->polling_mode = NFCSIM_POLL_NONE;
-	dev->shutting_down = shutdown;
-	dev->cb = NULL;
-	dev_kfree_skb(dev->clone_skb);
-	dev->clone_skb = NULL;
-
-	mutex_unlock(&dev->lock);
-
-	cancel_delayed_work_sync(&dev->poll_work);
-	cancel_delayed_work_sync(&dev->recv_work);
-}
-
-static int nfcsim_target_found(struct nfcsim *dev)
-{
-	struct nfc_target nfc_tgt;
-
-	DEV_DBG(dev, "\n");
-
-	memset(&nfc_tgt, 0, sizeof(struct nfc_target));
-
-	nfc_tgt.supported_protocols = NFC_PROTO_NFC_DEP_MASK;
-	nfc_targets_found(dev->nfc_dev, &nfc_tgt, 1);
-
-	return 0;
-}
-
-static int nfcsim_dev_up(struct nfc_dev *nfc_dev)
-{
-	struct nfcsim *dev = nfc_get_drvdata(nfc_dev);
-
-	DEV_DBG(dev, "\n");
-
-	mutex_lock(&dev->lock);
-
-	dev->up = 1;
-
-	mutex_unlock(&dev->lock);
-
-	return 0;
-}
-
-static int nfcsim_dev_down(struct nfc_dev *nfc_dev)
-{
-	struct nfcsim *dev = nfc_get_drvdata(nfc_dev);
-
-	DEV_DBG(dev, "\n");
-
-	mutex_lock(&dev->lock);
-
-	dev->up = 0;
-
-	mutex_unlock(&dev->lock);
-
-	return 0;
-}
-
-static int nfcsim_dep_link_up(struct nfc_dev *nfc_dev,
-			      struct nfc_target *target,
-			      u8 comm_mode, u8 *gb, size_t gb_len)
-{
-	int rc;
-	struct nfcsim *dev = nfc_get_drvdata(nfc_dev);
-	struct nfcsim *peer = dev->peer_dev;
-	u8 *remote_gb;
-	size_t remote_gb_len;
-
-	DEV_DBG(dev, "target_idx: %d, comm_mode: %d\n", target->idx, comm_mode);
-
-	mutex_lock(&peer->lock);
-
-	nfc_tm_activated(peer->nfc_dev, NFC_PROTO_NFC_DEP_MASK,
-			 NFC_COMM_ACTIVE, gb, gb_len);
-
-	remote_gb = nfc_get_local_general_bytes(peer->nfc_dev, &remote_gb_len);
-	if (!remote_gb) {
-		DEV_ERR(peer, "Can't get remote general bytes\n");
-
-		mutex_unlock(&peer->lock);
-		return -EINVAL;
-	}
-
-	mutex_unlock(&peer->lock);
-
-	mutex_lock(&dev->lock);
-
-	rc = nfc_set_remote_general_bytes(nfc_dev, remote_gb, remote_gb_len);
-	if (rc) {
-		DEV_ERR(dev, "Can't set remote general bytes\n");
-		mutex_unlock(&dev->lock);
-		return rc;
-	}
-
-	rc = nfc_dep_link_is_up(nfc_dev, target->idx, NFC_COMM_ACTIVE,
-				NFC_RF_INITIATOR);
-
-	mutex_unlock(&dev->lock);
-
-	return rc;
-}
-
-static int nfcsim_dep_link_down(struct nfc_dev *nfc_dev)
-{
-	struct nfcsim *dev = nfc_get_drvdata(nfc_dev);
-
-	DEV_DBG(dev, "\n");
-
-	nfcsim_cleanup_dev(dev, 0);
-
-	return 0;
-}
-
-static int nfcsim_start_poll(struct nfc_dev *nfc_dev,
-			     u32 im_protocols, u32 tm_protocols)
-{
-	struct nfcsim *dev = nfc_get_drvdata(nfc_dev);
-	int rc;
-
-	mutex_lock(&dev->lock);
-
-	if (dev->polling_mode != NFCSIM_POLL_NONE) {
-		DEV_ERR(dev, "Already in polling mode\n");
-		rc = -EBUSY;
-		goto exit;
-	}
-
-	if (im_protocols & NFC_PROTO_NFC_DEP_MASK)
-		dev->polling_mode |= NFCSIM_POLL_INITIATOR;
-
-	if (tm_protocols & NFC_PROTO_NFC_DEP_MASK)
-		dev->polling_mode |= NFCSIM_POLL_TARGET;
-
-	if (dev->polling_mode == NFCSIM_POLL_NONE) {
-		DEV_ERR(dev, "Unsupported polling mode\n");
-		rc = -EINVAL;
-		goto exit;
-	}
-
-	dev->initiator = 0;
-	dev->curr_polling_mode = NFCSIM_POLL_NONE;
-
-	queue_delayed_work(wq, &dev->poll_work, 0);
-
-	DEV_DBG(dev, "Start polling: im: 0x%X, tm: 0x%X\n", im_protocols,
-		tm_protocols);
-
-	rc = 0;
-exit:
-	mutex_unlock(&dev->lock);
-
-	return rc;
-}
-
-static void nfcsim_stop_poll(struct nfc_dev *nfc_dev)
-{
-	struct nfcsim *dev = nfc_get_drvdata(nfc_dev);
-
-	DEV_DBG(dev, "Stop poll\n");
-
-	mutex_lock(&dev->lock);
-
-	dev->polling_mode = NFCSIM_POLL_NONE;
-
-	mutex_unlock(&dev->lock);
-
-	cancel_delayed_work_sync(&dev->poll_work);
-}
-
-static int nfcsim_activate_target(struct nfc_dev *nfc_dev,
-				  struct nfc_target *target, u32 protocol)
-{
-	struct nfcsim *dev = nfc_get_drvdata(nfc_dev);
-
-	DEV_DBG(dev, "\n");
-
-	return -ENOTSUPP;
-}
-
-static void nfcsim_deactivate_target(struct nfc_dev *nfc_dev,
-				     struct nfc_target *target, u8 mode)
-{
-	struct nfcsim *dev = nfc_get_drvdata(nfc_dev);
-
-	DEV_DBG(dev, "\n");
-}
-
-static void nfcsim_wq_recv(struct work_struct *work)
-{
-	struct nfcsim *dev = container_of(work, struct nfcsim,
-					  recv_work.work);
-
-	mutex_lock(&dev->lock);
-
-	if (dev->shutting_down || !dev->up || !dev->clone_skb) {
-		dev_kfree_skb(dev->clone_skb);
-		goto exit;
-	}
-
-	if (dev->initiator) {
-		if (!dev->cb) {
-			DEV_ERR(dev, "Null recv callback\n");
-			dev_kfree_skb(dev->clone_skb);
-			goto exit;
-		}
-
-		dev->cb(dev->cb_context, dev->clone_skb, 0);
-		dev->cb = NULL;
-	} else {
-		nfc_tm_data_received(dev->nfc_dev, dev->clone_skb);
-	}
-
-exit:
-	dev->clone_skb = NULL;
-
-	mutex_unlock(&dev->lock);
-}
-
-static int nfcsim_tx(struct nfc_dev *nfc_dev, struct nfc_target *target,
-		     struct sk_buff *skb, data_exchange_cb_t cb,
-		     void *cb_context)
-{
-	struct nfcsim *dev = nfc_get_drvdata(nfc_dev);
-	struct nfcsim *peer = dev->peer_dev;
-	int err;
-
-	mutex_lock(&dev->lock);
-
-	if (dev->shutting_down || !dev->up) {
-		mutex_unlock(&dev->lock);
-		err = -ENODEV;
-		goto exit;
-	}
-
-	dev->cb = cb;
-	dev->cb_context = cb_context;
-
-	mutex_unlock(&dev->lock);
-
-	mutex_lock(&peer->lock);
-
-	peer->clone_skb = skb_clone(skb, GFP_KERNEL);
-
-	if (!peer->clone_skb) {
-		DEV_ERR(dev, "skb_clone failed\n");
-		mutex_unlock(&peer->lock);
-		err = -ENOMEM;
-		goto exit;
-	}
-
-	/* This simulates an arbitrary transmission delay between the 2 devices.
-	 * If packet transmission occurs immediately between them, we have a
-	 * non-stop flow of several tens of thousands SYMM packets per second
-	 * and a burning cpu.
-	 */
-	queue_delayed_work(wq, &peer->recv_work,
-			msecs_to_jiffies(dev->rx_delay));
-
-	mutex_unlock(&peer->lock);
-
-	err = 0;
-exit:
-	dev_kfree_skb(skb);
-
-	return err;
-}
-
-static int nfcsim_im_transceive(struct nfc_dev *nfc_dev,
-				struct nfc_target *target, struct sk_buff *skb,
-				data_exchange_cb_t cb, void *cb_context)
-{
-	return nfcsim_tx(nfc_dev, target, skb, cb, cb_context);
-}
-
-static int nfcsim_tm_send(struct nfc_dev *nfc_dev, struct sk_buff *skb)
-{
-	return nfcsim_tx(nfc_dev, NULL, skb, NULL, NULL);
-}
-
-static struct nfc_ops nfcsim_nfc_ops = {
-	.dev_up = nfcsim_dev_up,
-	.dev_down = nfcsim_dev_down,
-	.dep_link_up = nfcsim_dep_link_up,
-	.dep_link_down = nfcsim_dep_link_down,
-	.start_poll = nfcsim_start_poll,
-	.stop_poll = nfcsim_stop_poll,
-	.activate_target = nfcsim_activate_target,
-	.deactivate_target = nfcsim_deactivate_target,
-	.im_transceive = nfcsim_im_transceive,
-	.tm_send = nfcsim_tm_send,
-};
-
-static void nfcsim_set_polling_mode(struct nfcsim *dev)
-{
-	if (dev->polling_mode == NFCSIM_POLL_NONE) {
-		dev->curr_polling_mode = NFCSIM_POLL_NONE;
-		return;
-	}
-
-	if (dev->curr_polling_mode == NFCSIM_POLL_NONE) {
-		if (dev->polling_mode & NFCSIM_POLL_INITIATOR)
-			dev->curr_polling_mode = NFCSIM_POLL_INITIATOR;
-		else
-			dev->curr_polling_mode = NFCSIM_POLL_TARGET;
-
-		return;
-	}
-
-	if (dev->polling_mode == NFCSIM_POLL_DUAL) {
-		if (dev->curr_polling_mode == NFCSIM_POLL_TARGET)
-			dev->curr_polling_mode = NFCSIM_POLL_INITIATOR;
-		else
-			dev->curr_polling_mode = NFCSIM_POLL_TARGET;
-	}
-}
-
-static void nfcsim_wq_poll(struct work_struct *work)
-{
-	struct nfcsim *dev = container_of(work, struct nfcsim, poll_work.work);
-	struct nfcsim *peer = dev->peer_dev;
-
-	/* These work items run on an ordered workqueue and are therefore
-	 * serialized. So we can take both mutexes without being dead locked.
-	 */
-	mutex_lock(&dev->lock);
-	mutex_lock(&peer->lock);
-
-	nfcsim_set_polling_mode(dev);
-
-	if (dev->curr_polling_mode == NFCSIM_POLL_NONE) {
-		DEV_DBG(dev, "Not polling\n");
-		goto unlock;
-	}
-
-	DEV_DBG(dev, "Polling as %s",
-		dev->curr_polling_mode == NFCSIM_POLL_INITIATOR ?
-		"initiator\n" : "target\n");
-
-	if (dev->curr_polling_mode == NFCSIM_POLL_TARGET)
-		goto sched_work;
-
-	if (peer->curr_polling_mode == NFCSIM_POLL_TARGET) {
-		peer->polling_mode = NFCSIM_POLL_NONE;
-		dev->polling_mode = NFCSIM_POLL_NONE;
-
-		dev->initiator = 1;
-
-		nfcsim_target_found(dev);
-
-		goto unlock;
-	}
-
-sched_work:
-	/* This defines the delay for an initiator to check if the other device
-	 * is polling in target mode.
-	 * If the device starts in dual mode polling, it switches between
-	 * initiator and target at every round.
-	 * Because the wq is ordered and only 1 work item is executed at a time,
-	 * we'll always have one device polling as initiator and the other as
-	 * target at some point, even if both are started in dual mode.
-	 */
-	queue_delayed_work(wq, &dev->poll_work, msecs_to_jiffies(200));
-
-unlock:
-	mutex_unlock(&peer->lock);
-	mutex_unlock(&dev->lock);
-}
-
-static struct nfcsim *nfcsim_init_dev(void)
-{
-	struct nfcsim *dev;
-	int rc = -ENOMEM;
-
-	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
-	if (dev == NULL)
-		return ERR_PTR(-ENOMEM);
-
-	mutex_init(&dev->lock);
-
-	INIT_DELAYED_WORK(&dev->recv_work, nfcsim_wq_recv);
-	INIT_DELAYED_WORK(&dev->poll_work, nfcsim_wq_poll);
-
-	dev->nfc_dev = nfc_allocate_device(&nfcsim_nfc_ops,
-					   NFC_PROTO_NFC_DEP_MASK,
-					   0, 0);
-	if (!dev->nfc_dev)
-		goto error;
-
-	nfc_set_drvdata(dev->nfc_dev, dev);
-
-	rc = nfc_register_device(dev->nfc_dev);
-	if (rc)
-		goto free_nfc_dev;
-
-	dev->rx_delay = RX_DEFAULT_DELAY;
-	return dev;
-
-free_nfc_dev:
-	nfc_free_device(dev->nfc_dev);
-
-error:
-	kfree(dev);
-
-	return ERR_PTR(rc);
-}
-
-static void nfcsim_free_device(struct nfcsim *dev)
-{
-	nfc_unregister_device(dev->nfc_dev);
-
-	nfc_free_device(dev->nfc_dev);
-
-	kfree(dev);
-}
-
 static int __init nfcsim_init(void)
 {
+	struct nfcsim_link *link0, *link1;
 	int rc;
 
-	/* We need an ordered wq to ensure that poll_work items are executed
-	 * one at a time.
-	 */
-	wq = alloc_ordered_workqueue("nfcsim", 0);
-	if (!wq) {
+	link0 = nfcsim_link_new();
+	link1 = nfcsim_link_new();
+	if (!link0 || !link1) {
 		rc = -ENOMEM;
-		goto exit;
+		goto exit_err;
 	}
 
-	dev0 = nfcsim_init_dev();
+	nfcsim_debugfs_init();
+
+	dev0 = nfcsim_device_new(link0, link1);
 	if (IS_ERR(dev0)) {
 		rc = PTR_ERR(dev0);
-		goto exit;
+		goto exit_err;
 	}
 
-	dev1 = nfcsim_init_dev();
+	dev1 = nfcsim_device_new(link1, link0);
 	if (IS_ERR(dev1)) {
-		kfree(dev0);
+		nfcsim_device_free(dev0);
 
 		rc = PTR_ERR(dev1);
-		goto exit;
+		goto exit_err;
 	}
 
-	dev0->peer_dev = dev1;
-	dev1->peer_dev = dev0;
+	pr_info("nfcsim " NFCSIM_VERSION " initialized\n");
 
-	pr_debug("NFCsim " NFCSIM_VERSION " initialized\n");
+	return 0;
 
-	rc = 0;
-exit:
-	if (rc)
-		pr_err("Failed to initialize nfcsim driver (%d)\n",
-		       rc);
+exit_err:
+	pr_err("Failed to initialize nfcsim driver (%d)\n", rc);
+
+	nfcsim_link_free(link0);
+	nfcsim_link_free(link1);
 
 	return rc;
 }
 
 static void __exit nfcsim_exit(void)
 {
-	nfcsim_cleanup_dev(dev0, 1);
-	nfcsim_cleanup_dev(dev1, 1);
+	struct nfcsim_link *link0, *link1;
 
-	nfcsim_free_device(dev0);
-	nfcsim_free_device(dev1);
+	link0 = dev0->link_in;
+	link1 = dev0->link_out;
 
-	destroy_workqueue(wq);
+	nfcsim_device_free(dev0);
+	nfcsim_device_free(dev1);
+
+	nfcsim_link_free(link0);
+	nfcsim_link_free(link1);
+
+	nfcsim_debugfs_remove();
 }
 
 module_init(nfcsim_init);

drivers/nfc/pn533/usb.c

···
 		return -ENOMEM;
 
 	in_buf = kzalloc(in_buf_len, GFP_KERNEL);
-	if (!in_buf) {
-		rc = -ENOMEM;
-		goto out_free_phy;
-	}
+	if (!in_buf)
+		return -ENOMEM;
 
 	phy->udev = usb_get_dev(interface_to_usbdev(interface));
 	phy->interface = interface;
···
 	usb_free_urb(phy->out_urb);
 	usb_put_dev(phy->udev);
 	kfree(in_buf);
-out_free_phy:
-	kfree(phy);
+
 	return rc;
 }
 

drivers/nfc/port100.c

···
 	},
 	[NFC_DIGITAL_FRAMING_NFCF_NFC_DEP] = {
 		/* nfc_digital_framing_nfcf */
-		{ PORT100_IN_PROT_END, 0 },
+		{ PORT100_IN_PROT_INITIAL_GUARD_TIME,     18 },
+		{ PORT100_IN_PROT_ADD_CRC,                 1 },
+		{ PORT100_IN_PROT_CHECK_CRC,               1 },
+		{ PORT100_IN_PROT_MULTI_CARD,              0 },
+		{ PORT100_IN_PROT_ADD_PARITY,              0 },
+		{ PORT100_IN_PROT_CHECK_PARITY,            0 },
+		{ PORT100_IN_PROT_BITWISE_AC_RECV_MODE,    0 },
+		{ PORT100_IN_PROT_VALID_BIT_NUMBER,        8 },
+		{ PORT100_IN_PROT_CRYPTO1,                 0 },
+		{ PORT100_IN_PROT_ADD_SOF,                 0 },
+		{ PORT100_IN_PROT_CHECK_SOF,               0 },
+		{ PORT100_IN_PROT_ADD_EOF,                 0 },
+		{ PORT100_IN_PROT_CHECK_EOF,               0 },
+		{ PORT100_IN_PROT_DEAF_TIME,               4 },
+		{ PORT100_IN_PROT_CRM,                     0 },
+		{ PORT100_IN_PROT_CRM_MIN_LEN,             0 },
+		{ PORT100_IN_PROT_T1_TAG_FRAME,            0 },
+		{ PORT100_IN_PROT_RFCA,                    0 },
+		{ PORT100_IN_PROT_GUARD_TIME_AT_INITIATOR, 6 },
+		{ PORT100_IN_PROT_END,                     0 },
 	},
 	[NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED] = {
 		{ PORT100_IN_PROT_END, 0 },
···
 	struct urb *out_urb;
 	struct urb *in_urb;
 
+	/* This mutex protects the out_urb and avoids to submit a new command
+	 * through port100_send_frame_async() while the previous one is being
+	 * canceled through port100_abort_cmd().
+	 */
+	struct mutex out_urb_lock;
+
 	struct work_struct cmd_complete_work;
 
 	u8 cmd_type;
···
 	 * for any queuing/locking mechanism at driver level.
 	 */
 	struct port100_cmd *cmd;
+
+	bool cmd_cancel;
+	struct completion cmd_cancel_done;
 };
 
 struct port100_cmd {
···
 {
 	int rc;
 
+	mutex_lock(&dev->out_urb_lock);
+
+	init_completion(&dev->cmd_cancel_done);
+
+	usb_kill_urb(dev->out_urb);
+
 	dev->out_urb->transfer_buffer = ack_frame;
 	dev->out_urb->transfer_buffer_length = sizeof(ack_frame);
 	rc = usb_submit_urb(dev->out_urb, GFP_KERNEL);
+
+	/* Set the cmd_cancel flag only if the URB has been successfully
+	 * submitted. It will be reset by the out URB completion callback
+	 * port100_send_complete().
+	 */
+	dev->cmd_cancel = !rc;
+
+	mutex_unlock(&dev->out_urb_lock);
+
+	if (!rc)
+		wait_for_completion(&dev->cmd_cancel_done);
 
 	return rc;
 }
···
 				    struct sk_buff *in, int in_len)
 {
 	int rc;
+
+	mutex_lock(&dev->out_urb_lock);
+
+	/* A command cancel frame as been sent through dev->out_urb. Don't try
+	 * to submit a new one.
+	 */
+	if (dev->cmd_cancel) {
+		rc = -EAGAIN;
+		goto exit;
+	}
 
 	dev->out_urb->transfer_buffer = out->data;
 	dev->out_urb->transfer_buffer_length = out->len;
···
 
 	rc = usb_submit_urb(dev->out_urb, GFP_KERNEL);
 	if (rc)
-		return rc;
+		goto exit;
 
 	rc = port100_submit_urb_for_ack(dev, GFP_KERNEL);
 	if (rc)
-		goto error;
+		usb_unlink_urb(dev->out_urb);
 
-	return 0;
+exit:
+	mutex_unlock(&dev->out_urb_lock);
 
-error:
-	usb_unlink_urb(dev->out_urb);
 	return rc;
 }
 
···
 	int  resp_len = PORT100_FRAME_HEADER_LEN +
 			PORT100_FRAME_MAX_PAYLOAD_LEN +
 			PORT100_FRAME_TAIL_LEN;
+
+	if (dev->cmd) {
+		nfc_err(&dev->interface->dev,
+			"A command is still in process\n");
+		return -EBUSY;
+	}
 
 	resp = alloc_skb(resp_len, GFP_KERNEL);
 	if (!resp)
···
 static void port100_send_complete(struct urb *urb)
 {
 	struct port100 *dev = urb->context;
+
+	if (dev->cmd_cancel) {
+		dev->cmd_cancel = false;
+		complete(&dev->cmd_cancel_done);
+	}
 
 	switch (urb->status) {
 	case 0:
···
 		return -ENOMEM;
 
 	*skb_put(skb, 1) = on ? 1 : 0;
+
+	/* Cancel the last command if the device is being switched off */
+	if (!on)
+		port100_abort_cmd(ddev);
 
 	resp = port100_send_cmd_sync(dev, PORT100_CMD_SWITCH_RF, skb);
 
···
 	if (!dev)
 		return -ENOMEM;
 
+	mutex_init(&dev->out_urb_lock);
 	dev->udev = usb_get_dev(interface_to_usbdev(interface));
 	dev->interface = interface;
 	usb_set_intfdata(interface, dev);

drivers/nfc/trf7970a.c

···
 	if (ret)
 		goto err_out;
 
+	ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL, 0);
+	if (ret)
+		goto err_out;
+
 	usleep_range(1000, 2000);
 
 	trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON;

include/net/nfc/digital.h

···
 	struct list_head cmd_queue;
 	struct mutex cmd_lock;
 
-	struct work_struct poll_work;
+	struct delayed_work poll_work;
 
 	u8 curr_protocol;
 	u8 curr_rf_tech;
 	u8 curr_nfc_dep_pni;
 	u8 did;
+	u16 dep_rwt;
 
 	u8 local_payload_max;
 	u8 remote_payload_max;
···
 	int nack_count;
 
 	struct sk_buff *saved_skb;
-	unsigned int saved_skb_len;
 
 	u16 target_fsc;
 

include/net/nfc/llc.h

···
 				 int tx_tailroom, llc_failure_t llc_failure);
 void nfc_llc_free(struct nfc_llc *llc);
 
-void nfc_llc_get_rx_head_tail_room(struct nfc_llc *llc, int *rx_headroom,
-				   int *rx_tailroom);
-
-
 int nfc_llc_start(struct nfc_llc *llc);
 int nfc_llc_stop(struct nfc_llc *llc);
 void nfc_llc_rcv_from_drv(struct nfc_llc *llc, struct sk_buff *skb);

net/nfc/digital_core.c

···
 
 #define DIGITAL_PROTO_ISO15693_RF_TECH	NFC_PROTO_ISO15693_MASK
 
+/* Delay between each poll frame (ms) */
+#define DIGITAL_POLL_INTERVAL 10
+
 struct digital_cmd {
 	struct list_head queue;
 
···
 		mutex_unlock(&ddev->cmd_lock);
 		return;
 	}
+
+	cmd->pending = 1;
 
 	mutex_unlock(&ddev->cmd_lock);
 
···
 
 	mutex_unlock(&ddev->poll_lock);
 
-	schedule_work(&ddev->poll_work);
+	schedule_delayed_work(&ddev->poll_work,
+			      msecs_to_jiffies(DIGITAL_POLL_INTERVAL));
 }
 
 static void digital_wq_poll(struct work_struct *work)
···
 	struct digital_poll_tech *poll_tech;
 	struct nfc_digital_dev *ddev = container_of(work,
 						    struct nfc_digital_dev,
-						    poll_work);
+						    poll_work.work);
 	mutex_lock(&ddev->poll_lock);
 
 	if (!ddev->poll_tech_count) {
···
 		return -EINVAL;
 	}
 
-	schedule_work(&ddev->poll_work);
+	schedule_delayed_work(&ddev->poll_work, 0);
 
 	return 0;
 }
···
 
 	mutex_unlock(&ddev->poll_lock);
 
-	cancel_work_sync(&ddev->poll_work);
+	cancel_delayed_work_sync(&ddev->poll_work);
 
 	digital_abort_cmd(ddev);
 }
···
 static int digital_dep_link_down(struct nfc_dev *nfc_dev)
 {
 	struct nfc_digital_dev *ddev = nfc_get_drvdata(nfc_dev);
+
+	digital_abort_cmd(ddev);
 
 	ddev->curr_protocol = 0;
 
···
 	INIT_WORK(&ddev->cmd_complete_work, digital_wq_cmd_complete);
 
 	mutex_init(&ddev->poll_lock);
-	INIT_WORK(&ddev->poll_work, digital_wq_poll);
+	INIT_DELAYED_WORK(&ddev->poll_work, digital_wq_poll);
 
 	if (supported_protocols & NFC_PROTO_JEWEL_MASK)
 		ddev->protocols |= NFC_PROTO_JEWEL_MASK;
···
 	ddev->poll_tech_count = 0;
 	mutex_unlock(&ddev->poll_lock);
 
-	cancel_work_sync(&ddev->poll_work);
+	cancel_delayed_work_sync(&ddev->poll_work);
 	cancel_work_sync(&ddev->cmd_work);
 	cancel_work_sync(&ddev->cmd_complete_work);
 
 	list_for_each_entry_safe(cmd, n, &ddev->cmd_queue, queue) {
 		list_del(&cmd->queue);
+
+		/* Call the command callback if any and pass it a ENODEV error.
+		 * This gives a chance to the command issuer to free any
+		 * allocated buffer.
+		 */
+		if (cmd->cmd_cb)
+			cmd->cmd_cb(ddev, cmd->cb_context, ERR_PTR(-ENODEV));
+
 		kfree(cmd->mdaa_params);
 		kfree(cmd);
 	}

net/nfc/digital_dep.c

···
 #define DIGITAL_ATR_REQ_MIN_SIZE 16
 #define DIGITAL_ATR_REQ_MAX_SIZE 64
 
+#define DIGITAL_ATR_RES_TO_WT(s)	((s) & 0xF)
+
 #define DIGITAL_DID_MAX	14
 
 #define DIGITAL_PAYLOAD_SIZE_MAX	254
···
 #define DIGITAL_NFC_DEP_NAD_BIT_SET(pfb) ((pfb) & 0x08)
 #define DIGITAL_NFC_DEP_DID_BIT_SET(pfb) ((pfb) & DIGITAL_NFC_DEP_PFB_DID_BIT)
 #define DIGITAL_NFC_DEP_PFB_PNI(pfb)     ((pfb) & 0x03)
+
+#define DIGITAL_NFC_DEP_RTOX_VALUE(data) ((data) & 0x3F)
+#define DIGITAL_NFC_DEP_RTOX_MAX	 59
 
 #define DIGITAL_NFC_DEP_PFB_I_PDU          0x00
 #define DIGITAL_NFC_DEP_PFB_ACK_NACK_PDU   0x40
···
 	[1] = 128,
 	[2] = 192,
 	[3] = 254
+};
+
+/* Response Waiting Time for ATR_RES PDU in ms
+ *
+ * RWT(ATR_RES) = RWT(nfcdep,activation) + dRWT(nfcdep) + dT(nfcdep,initiator)
+ *
+ * with:
+ *  RWT(nfcdep,activation) = 4096 * 2^12 / f(c) s
+ *  dRWT(nfcdep) = 16 / f(c) s
+ *  dT(nfcdep,initiator) = 100 ms
+ *  f(c) = 13560000 Hz
+ */
+#define DIGITAL_ATR_RES_RWT 1337
+
+/* Response Waiting Time for other DEP PDUs in ms
+ *
+ * max_rwt = rwt + dRWT(nfcdep) + dT(nfcdep,initiator)
+ *
+ * with:
+ *  rwt = (256 * 16 / f(c)) * 2^wt s
+ *  dRWT(nfcdep) = 16 / f(c) s
+ *  dT(nfcdep,initiator) = 100 ms
+ *  f(c) = 13560000 Hz
+ *  0 <= wt <= 14 (given by the target by the TO field of ATR_RES response)
+ */
+#define DIGITAL_NFC_DEP_IN_MAX_WT 14
+#define DIGITAL_NFC_DEP_TG_MAX_WT 8
+static const u16 digital_rwt_map[DIGITAL_NFC_DEP_IN_MAX_WT + 1] = {
+	100,  101,  101,  102,  105,
+	110,  119,  139,  177,  255,
+	409,  719, 1337, 2575, 5049,
 };
 
 static u8 digital_payload_bits_to_size(u8 payload_bits)
···
 			return ERR_PTR(-ENOMEM);
 		}
 
-		skb_reserve(new_skb, ddev->tx_headroom + NFC_HEADER_SIZE +
-					DIGITAL_NFC_DEP_REQ_RES_HEADROOM);
 		memcpy(skb_put(new_skb, ddev->remote_payload_max), skb->data,
 		       ddev->remote_payload_max);
 		skb_pull(skb, ddev->remote_payload_max);
···
 
 	ddev->skb_add_crc(skb);
 
-	rc = digital_in_send_cmd(ddev, skb, 500, digital_in_recv_psl_res,
-				 target);
+	rc = digital_in_send_cmd(ddev, skb, ddev->dep_rwt,
+				 digital_in_recv_psl_res, target);
 	if (rc)
 		kfree_skb(skb);
 
···
 	struct nfc_target *target = arg;
 	struct digital_atr_res *atr_res;
 	u8 gb_len, payload_bits;
+	u8 wt;
 	int rc;
 
 	if (IS_ERR(resp)) {
···
 	gb_len = resp->len - sizeof(struct digital_atr_res);
 
 	atr_res = (struct digital_atr_res *)resp->data;
+
+	wt = DIGITAL_ATR_RES_TO_WT(atr_res->to);
+	if (wt > DIGITAL_NFC_DEP_IN_MAX_WT)
+		wt = DIGITAL_NFC_DEP_IN_MAX_WT;
+	ddev->dep_rwt = digital_rwt_map[wt];
 
 	payload_bits = DIGITAL_PAYLOAD_PP_TO_BITS(atr_res->pp);
 	ddev->remote_payload_max = digital_payload_bits_to_size(payload_bits);
···
 
 	ddev->skb_add_crc(skb);
 
-	rc = digital_in_send_cmd(ddev, skb, 500, digital_in_recv_atr_res,
-				 target);
+	rc = digital_in_send_cmd(ddev, skb, DIGITAL_ATR_RES_RWT,
+				 digital_in_recv_atr_res, target);
 	if (rc)
 		kfree_skb(skb);
 
···
 
 	ddev->skb_add_crc(skb);
 
-	ddev->saved_skb = skb_get(skb);
-	ddev->saved_skb_len = skb->len;
+	ddev->saved_skb = pskb_copy(skb, GFP_KERNEL);
 
-	rc = digital_in_send_cmd(ddev, skb, 1500, digital_in_recv_dep_res,
-				 data_exch);
+	rc = digital_in_send_cmd(ddev, skb, ddev->dep_rwt,
+				 digital_in_recv_dep_res, data_exch);
 	if (rc) {
 		kfree_skb(skb);
 		kfree_skb(ddev->saved_skb);
···
 
 	ddev->skb_add_crc(skb);
 
-	rc = digital_in_send_cmd(ddev, skb, 1500, digital_in_recv_dep_res,
-				 data_exch);
+	rc = digital_in_send_cmd(ddev, skb, ddev->dep_rwt,
+				 digital_in_recv_dep_res, data_exch);
 	if (rc)
 		kfree_skb(skb);
 
···
 
 	ddev->skb_add_crc(skb);
 
-	rc = digital_in_send_cmd(ddev, skb, 1500, digital_in_recv_dep_res,
-				 data_exch);
+	rc = digital_in_send_cmd(ddev, skb, ddev->dep_rwt,
+				 digital_in_recv_dep_res, data_exch);
 	if (rc)
 		kfree_skb(skb);
 
···
 	struct digital_dep_req_res *dep_req;
 	struct sk_buff *skb;
 	int rc;
+	u16 rwt_int;
+
+	rwt_int = ddev->dep_rwt * rtox;
+	if (rwt_int > digital_rwt_map[DIGITAL_NFC_DEP_IN_MAX_WT])
+		rwt_int = digital_rwt_map[DIGITAL_NFC_DEP_IN_MAX_WT];
 
 	skb = digital_skb_alloc(ddev, 1);
 	if (!skb)
···
 
 	ddev->skb_add_crc(skb);
 
-	ddev->saved_skb = skb_get(skb);
-	ddev->saved_skb_len = skb->len;
-
-	rc = digital_in_send_cmd(ddev, skb, 1500, digital_in_recv_dep_res,
-				 data_exch);
-	if (rc) {
+	rc = digital_in_send_cmd(ddev, skb, rwt_int,
+				 digital_in_recv_dep_res, data_exch);
+	if (rc)
 		kfree_skb(skb);
-		kfree_skb(ddev->saved_skb);
-		ddev->saved_skb = NULL;
-	}
 
 	return rc;
 }
···
 static int digital_in_send_saved_skb(struct nfc_digital_dev *ddev,
 				     struct digital_data_exch *data_exch)
 {
-	skb_get(ddev->saved_skb);
-	skb_push(ddev->saved_skb, ddev->saved_skb_len);
+	int rc;
 
-	return digital_in_send_cmd(ddev, ddev->saved_skb, 1500,
-				   digital_in_recv_dep_res, data_exch);
+	if (!ddev->saved_skb)
+		return -EINVAL;
+
+	skb_get(ddev->saved_skb);
+
+	rc = digital_in_send_cmd(ddev, ddev->saved_skb, ddev->dep_rwt,
+				 digital_in_recv_dep_res, data_exch);
+	if (rc)
+		kfree_skb(ddev->saved_skb);
+
+	return rc;
 }
 
 static void digital_in_recv_dep_res(struct nfc_digital_dev *ddev, void *arg,
···
 	u8 pfb;
 	uint size;
 	int rc;
+	u8 rtox;
 
 	if (IS_ERR(resp)) {
 		rc = PTR_ERR(resp);
 		resp = NULL;
 
-		if (((rc != -ETIMEDOUT) || ddev->nack_count) &&
+		if ((rc == -EIO || (rc == -ETIMEDOUT && ddev->nack_count)) &&
 		    (ddev->nack_count++ < DIGITAL_NFC_DEP_N_RETRY_NACK)) {
 			ddev->atn_count = 0;
 
···
 		break;
 
 	case DIGITAL_NFC_DEP_PFB_ACK_NACK_PDU:
+		if (DIGITAL_NFC_DEP_NACK_BIT_SET(pfb)) {
+			PROTOCOL_ERR("14.12.4.5");
+			rc = -EIO;
+			goto exit;
+		}
+
 		if (DIGITAL_NFC_DEP_PFB_PNI(pfb) != ddev->curr_nfc_dep_pni) {
 			PROTOCOL_ERR("14.12.3.3");
 			rc = -EIO;
···
 		ddev->curr_nfc_dep_pni =
 			DIGITAL_NFC_DEP_PFB_PNI(ddev->curr_nfc_dep_pni + 1);
 
-		if (ddev->chaining_skb && !DIGITAL_NFC_DEP_NACK_BIT_SET(pfb)) {
-			kfree_skb(ddev->saved_skb);
-			ddev->saved_skb = NULL;
-
-			rc = digital_in_send_dep_req(ddev, NULL,
-						     ddev->chaining_skb,
-						     ddev->data_exch);
-			if (rc)
-				goto error;
-
-			return;
+		if (!ddev->chaining_skb) {
+			PROTOCOL_ERR("14.12.4.3");
+			rc = -EIO;
+			goto exit;
 		}
 
-		pr_err("Received a ACK/NACK PDU\n");
-		rc = -EINVAL;
-		goto exit;
+		/* The initiator has received a valid ACK. Free the last sent
+		 * PDU and keep on sending chained skb.
+		 */
+		kfree_skb(ddev->saved_skb);
+		ddev->saved_skb = NULL;
+
+		rc = digital_in_send_dep_req(ddev, NULL,
+					     ddev->chaining_skb,
+					     ddev->data_exch);
+		if (rc)
+			goto error;
+
+		goto free_resp;
 
 	case DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU:
 		if (!DIGITAL_NFC_DEP_PFB_IS_TIMEOUT(pfb)) { /* ATN */
 			rc = digital_in_send_saved_skb(ddev, data_exch);
-			if (rc) {
-				kfree_skb(ddev->saved_skb);
+			if (rc)
 				goto error;
-			}
 
-			return;
+			goto free_resp;
 		}
 
-		kfree_skb(ddev->saved_skb);
-		ddev->saved_skb = NULL;
+		if (ddev->atn_count || ddev->nack_count) {
+			PROTOCOL_ERR("14.12.4.4");
+			rc = -EIO;
+			goto error;
+		}
 
-		rc = digital_in_send_rtox(ddev, data_exch, resp->data[0]);
+		rtox = DIGITAL_NFC_DEP_RTOX_VALUE(resp->data[0]);
+		if (!rtox || rtox > DIGITAL_NFC_DEP_RTOX_MAX) {
+			PROTOCOL_ERR("14.8.4.1");
+			rc = -EIO;
+			goto error;
+		}
+
+		rc = digital_in_send_rtox(ddev, data_exch, rtox);
 		if (rc)
 			goto error;
 
-		kfree_skb(resp);
-		return;
+		goto free_resp;
 	}
 
 exit:
···
 
 	if (rc)
 		kfree_skb(resp);
+
+	return;
+
+free_resp:
+	dev_kfree_skb(resp);
 }
 
 int digital_in_send_dep_req(struct nfc_digital_dev *ddev,
···
 
 	ddev->skb_add_crc(tmp_skb);
 
-	ddev->saved_skb = skb_get(tmp_skb);
-	ddev->saved_skb_len = tmp_skb->len;
+	ddev->saved_skb = pskb_copy(tmp_skb, GFP_KERNEL);
 
-	rc = digital_in_send_cmd(ddev, tmp_skb, 1500, digital_in_recv_dep_res,
-				 data_exch);
+	rc = digital_in_send_cmd(ddev, tmp_skb, ddev->dep_rwt,
+				 digital_in_recv_dep_res, data_exch);
 	if (rc) {
 		if (tmp_skb != skb)
 			kfree_skb(tmp_skb);
···
 
 	ddev->skb_add_crc(skb);
 
-	ddev->saved_skb = skb_get(skb);
-	ddev->saved_skb_len = skb->len;
+	ddev->saved_skb = pskb_copy(skb, GFP_KERNEL);
 
 	rc = digital_tg_send_cmd(ddev, skb, 1500, digital_tg_recv_dep_req,
 				 data_exch);
···
 
 static int digital_tg_send_saved_skb(struct nfc_digital_dev *ddev)
 {
-	skb_get(ddev->saved_skb);
-	skb_push(ddev->saved_skb, ddev->saved_skb_len);
+	int rc;
 
-	return digital_tg_send_cmd(ddev, ddev->saved_skb, 1500,
-				   digital_tg_recv_dep_req, NULL);
+	if (!ddev->saved_skb)
+		return -EINVAL;
+
+	skb_get(ddev->saved_skb);
+
+	rc = digital_tg_send_cmd(ddev, ddev->saved_skb, 1500,
+				 digital_tg_recv_dep_req, NULL);
+	if (rc)
+		kfree_skb(ddev->saved_skb);
+
+	return rc;
 }
 
 static void digital_tg_recv_dep_req(struct nfc_digital_dev *ddev, void *arg,
···
 	case DIGITAL_NFC_DEP_PFB_I_PDU:
 		pr_debug("DIGITAL_NFC_DEP_PFB_I_PDU\n");
 
-		if ((ddev->atn_count && (DIGITAL_NFC_DEP_PFB_PNI(pfb - 1) !=
-						ddev->curr_nfc_dep_pni)) ||
-		    (DIGITAL_NFC_DEP_PFB_PNI(pfb) != ddev->curr_nfc_dep_pni)) {
+		if (ddev->atn_count) {
+			/* The target has received (and replied to) at least one
+			 * ATN DEP_REQ.
+			 */
+			ddev->atn_count = 0;
+
+			/* pni of resp PDU equal to the target current pni - 1
+			 * means resp is the previous DEP_REQ PDU received from
+			 * the initiator so the target replies with saved_skb
+			 * which is the previous DEP_RES saved in
+			 * digital_tg_send_dep_res().
+			 */
+			if (DIGITAL_NFC_DEP_PFB_PNI(pfb) ==
+			  DIGITAL_NFC_DEP_PFB_PNI(ddev->curr_nfc_dep_pni - 1)) {
+				rc = digital_tg_send_saved_skb(ddev);
+				if (rc)
+					goto exit;
+
+				goto free_resp;
+			}
+
+			/* atn_count > 0 and PDU pni != curr_nfc_dep_pni - 1
+			 * means the target probably did not received the last
+			 * DEP_REQ PDU sent by the initiator. The target
+			 * fallbacks to normal processing then.
+			 */
+		}
+
+		if (DIGITAL_NFC_DEP_PFB_PNI(pfb) != ddev->curr_nfc_dep_pni) {
 			PROTOCOL_ERR("14.12.3.4");
 			rc = -EIO;
 			goto exit;
-		}
-
-		if (ddev->atn_count) {
-			ddev->atn_count = 0;
-
-			rc = digital_tg_send_saved_skb(ddev);
-			if (rc)
-				goto exit;
-
-			return;
 		}
 
 		kfree_skb(ddev->saved_skb);
···
 		rc = 0;
 		break;
 	case DIGITAL_NFC_DEP_PFB_ACK_NACK_PDU:
-		if (!DIGITAL_NFC_DEP_NACK_BIT_SET(pfb)) { /* ACK */
-			if ((ddev->atn_count &&
-			     (DIGITAL_NFC_DEP_PFB_PNI(pfb - 1) !=
-						ddev->curr_nfc_dep_pni)) ||
-			    (DIGITAL_NFC_DEP_PFB_PNI(pfb) !=
-						ddev->curr_nfc_dep_pni) ||
-			    !ddev->chaining_skb || !ddev->saved_skb) {
-				rc = -EIO;
-				goto exit;
-			}
-
-			if (ddev->atn_count) {
-				ddev->atn_count = 0;
-
-				rc = digital_tg_send_saved_skb(ddev);
-				if (rc)
-					goto exit;
-
-				return;
-			}
-
-			kfree_skb(ddev->saved_skb);
-			ddev->saved_skb = NULL;
-
-			rc = digital_tg_send_dep_res(ddev, ddev->chaining_skb);
-			if (rc)
-				goto exit;
-		} else { /* NACK */
-			if ((DIGITAL_NFC_DEP_PFB_PNI(pfb + 1) !=
-						ddev->curr_nfc_dep_pni) ||
-			    !ddev->saved_skb) {
+		if (DIGITAL_NFC_DEP_NACK_BIT_SET(pfb)) { /* NACK */
+			if (DIGITAL_NFC_DEP_PFB_PNI(pfb + 1) !=
+						ddev->curr_nfc_dep_pni) {
 				rc = -EIO;
 				goto exit;
 			}
···
 			ddev->atn_count = 0;
 
 			rc = digital_tg_send_saved_skb(ddev);
-			if (rc) {
-				kfree_skb(ddev->saved_skb);
+			if (rc)
 				goto exit;
-			}
+
+			goto free_resp;
 		}
 
-		return;
+		/* ACK */
+		if (ddev->atn_count) {
+			/* The target has previously recevied one or more ATN
+			 * PDUs.
+			 */
+			ddev->atn_count = 0;
+
+			/* If the ACK PNI is equal to the target PNI - 1 means
+			 * that the initiator did not receive the previous PDU
+			 * sent by the target so re-send it.
+			 */
+			if (DIGITAL_NFC_DEP_PFB_PNI(pfb + 1) ==
+						ddev->curr_nfc_dep_pni) {
+				rc = digital_tg_send_saved_skb(ddev);
+				if (rc)
+					goto exit;
+
+				goto free_resp;
+			}
+
+			/* Otherwise, the target did not receive the previous
+			 * ACK PDU from the initiator. Fallback to normal
+			 * processing of chained PDU then.
+			 */
+		}
+
+		/* Keep on sending chained PDU */
+		if (!ddev->chaining_skb ||
+		    DIGITAL_NFC_DEP_PFB_PNI(pfb) !=
+					ddev->curr_nfc_dep_pni) {
+			rc = -EIO;
+			goto exit;
+		}
+
+		kfree_skb(ddev->saved_skb);
+		ddev->saved_skb = NULL;
+
+		rc = digital_tg_send_dep_res(ddev, ddev->chaining_skb);
+		if (rc)
+			goto exit;
+
+		goto free_resp;
 	case DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU:
 		if (DIGITAL_NFC_DEP_PFB_IS_TIMEOUT(pfb)) {
 			rc = -EINVAL;
···
 
 		ddev->atn_count++;
 
-		kfree_skb(resp);
-		return;
+		goto free_resp;
 	}
 
 	rc = nfc_tm_data_received(ddev->nfc_dev, resp);
···
 
 	if (rc)
 		kfree_skb(resp);
+
+	return;
+
+free_resp:
+	dev_kfree_skb(resp);
 }
 
 int digital_tg_send_dep_res(struct nfc_digital_dev *ddev, struct sk_buff *skb)
···
 
 	ddev->skb_add_crc(tmp_skb);
 
-	ddev->saved_skb = skb_get(tmp_skb);
-	ddev->saved_skb_len = tmp_skb->len;
+	ddev->saved_skb = pskb_copy(tmp_skb, GFP_KERNEL);
 
 	rc = digital_tg_send_cmd(ddev, tmp_skb, 1500, digital_tg_recv_dep_req,
 				 NULL);
···
 	atr_res->dir = DIGITAL_NFC_DEP_FRAME_DIR_IN;
 	atr_res->cmd = DIGITAL_CMD_ATR_RES;
 	memcpy(atr_res->nfcid3, atr_req->nfcid3, sizeof(atr_req->nfcid3));
-	atr_res->to = 8;
+	atr_res->to = DIGITAL_NFC_DEP_TG_MAX_WT;
 
 	ddev->local_payload_max = DIGITAL_PAYLOAD_SIZE_MAX;
 	payload_bits = digital_payload_size_to_bits(ddev->local_payload_max);

net/nfc/digital_technology.c

···
 int digital_tg_listen_nfcf(struct nfc_digital_dev *ddev, u8 rf_tech)
 {
 	int rc;
-	u8 *nfcid2;
 
 	rc = digital_tg_config_nfcf(ddev, rf_tech);
 	if (rc)
 		return rc;
 
-	nfcid2 = kzalloc(NFC_NFCID2_MAXSIZE, GFP_KERNEL);
-	if (!nfcid2)
-		return -ENOMEM;
-
-	nfcid2[0] = DIGITAL_SENSF_NFCID2_NFC_DEP_B1;
-	nfcid2[1] = DIGITAL_SENSF_NFCID2_NFC_DEP_B2;
-	get_random_bytes(nfcid2 + 2, NFC_NFCID2_MAXSIZE - 2);
-
-	return digital_tg_listen(ddev, 300, digital_tg_recv_sensf_req, nfcid2);
+	return digital_tg_listen(ddev, 300, digital_tg_recv_sensf_req, NULL);
 }
 
 void digital_tg_recv_md_req(struct nfc_digital_dev *ddev, void *arg,

net/nfc/hci/llc.c

···
 	kfree(llc);
 }
 
-inline void nfc_llc_get_rx_head_tail_room(struct nfc_llc *llc, int *rx_headroom,
-					  int *rx_tailroom)
-{
-	*rx_headroom = llc->rx_headroom;
-	*rx_tailroom = llc->rx_tailroom;
-}
-
-inline int nfc_llc_start(struct nfc_llc *llc)
+int nfc_llc_start(struct nfc_llc *llc)
 {
 	return llc->ops->start(llc);
 }
 EXPORT_SYMBOL(nfc_llc_start);
 
-inline int nfc_llc_stop(struct nfc_llc *llc)
+int nfc_llc_stop(struct nfc_llc *llc)
 {
 	return llc->ops->stop(llc);
 }
 EXPORT_SYMBOL(nfc_llc_stop);
 
-inline void nfc_llc_rcv_from_drv(struct nfc_llc *llc, struct sk_buff *skb)
+void nfc_llc_rcv_from_drv(struct nfc_llc *llc, struct sk_buff *skb)
 {
 	llc->ops->rcv_from_drv(llc, skb);
 }
 
-inline int nfc_llc_xmit_from_hci(struct nfc_llc *llc, struct sk_buff *skb)
+int nfc_llc_xmit_from_hci(struct nfc_llc *llc, struct sk_buff *skb)
 {
 	return llc->ops->xmit_from_hci(llc, skb);
 }
 
-inline void *nfc_llc_get_data(struct nfc_llc *llc)
+void *nfc_llc_get_data(struct nfc_llc *llc)
 {
 	return llc->data;
 }

net/nfc/llcp_commands.c

···
 		goto error_tlv;
 	}
 
-	if (service_name_tlv != NULL)
-		skb = llcp_add_tlv(skb, service_name_tlv,
-				   service_name_tlv_length);
-
-	skb = llcp_add_tlv(skb, miux_tlv, miux_tlv_length);
-	skb = llcp_add_tlv(skb, rw_tlv, rw_tlv_length);
+	llcp_add_tlv(skb, service_name_tlv, service_name_tlv_length);
+	llcp_add_tlv(skb, miux_tlv, miux_tlv_length);
+	llcp_add_tlv(skb, rw_tlv, rw_tlv_length);
 
 	skb_queue_tail(&local->tx_queue, skb);
 
-	return 0;
+	err = 0;
 
 error_tlv:
-	pr_err("error %d\n", err);
+	if (err)
+		pr_err("error %d\n", err);
 
 	kfree(service_name_tlv);
 	kfree(miux_tlv);
···
 		goto error_tlv;
 	}
 
-	skb = llcp_add_tlv(skb, miux_tlv, miux_tlv_length);
-	skb = llcp_add_tlv(skb, rw_tlv, rw_tlv_length);
+	llcp_add_tlv(skb, miux_tlv, miux_tlv_length);
+	llcp_add_tlv(skb, rw_tlv, rw_tlv_length);
 
 	skb_queue_tail(&local->tx_queue, skb);
 
-	return 0;
+	err = 0;
 
 error_tlv:
-	pr_err("error %d\n", err);
+	if (err)
+		pr_err("error %d\n", err);
 
 	kfree(miux_tlv);
 	kfree(rw_tlv);

net/nfc/llcp_core.c

···
 			int ret;
 
 			pr_debug("Sending pending skb\n");
-			print_hex_dump(KERN_DEBUG, "LLCP Tx: ",
-				       DUMP_PREFIX_OFFSET, 16, 1,
-				       skb->data, skb->len, true);
+			print_hex_dump_debug("LLCP Tx: ", DUMP_PREFIX_OFFSET,
+					     16, 1, skb->data, skb->len, true);
 
 			if (ptype == LLCP_PDU_DISC && sk != NULL &&
 			    sk->sk_state == LLCP_DISCONNECTING) {
···
 	pr_debug("ptype 0x%x dsap 0x%x ssap 0x%x\n", ptype, dsap, ssap);
 
 	if (ptype != LLCP_PDU_SYMM)
-		print_hex_dump(KERN_DEBUG, "LLCP Rx: ", DUMP_PREFIX_OFFSET,
-			       16, 1, skb->data, skb->len, true);
+		print_hex_dump_debug("LLCP Rx: ", DUMP_PREFIX_OFFSET, 16, 1,
+				     skb->data, skb->len, true);
 
 	switch (ptype) {
 	case LLCP_PDU_SYMM: