NFC: digital: Rearrange NFC-DEP DEP_REQ/DEP_RES Code

Rearrange some of the code in digital_in_recv_dep_res()
and digital_tg_recv_dep_req() so the initial code looks
similar.  The real reason is prepare the code for some
upcoming patches that require these changes.
Reviewed-by: Thierry Escande <thierry.escande@linux.intel.com>
Tested-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

net/nfc/digital_dep.c

@@ -400,10 +400,10 @@ static void digital_in_recv_dep_res(struct nfc_digital_dev *ddev, void *arg,
 		goto exit;
 	}
 
+	size = sizeof(struct digital_dep_req_res);
 	dep_res = (struct digital_dep_req_res *)resp->data;
 
-	if (resp->len < sizeof(struct digital_dep_req_res) ||
-	    dep_res->dir != DIGITAL_NFC_DEP_FRAME_DIR_IN ||
+	if (resp->len < size || dep_res->dir != DIGITAL_NFC_DEP_FRAME_DIR_IN ||
 	    dep_res->cmd != DIGITAL_CMD_DEP_RES) {
 		rc = -EIO;
 		goto error;
@@ -411,6 +411,16 @@ static void digital_in_recv_dep_res(struct nfc_digital_dev *ddev, void *arg,
 
 	pfb = dep_res->pfb;
 
+	if (DIGITAL_NFC_DEP_DID_BIT_SET(pfb))
+		size++;
+
+	if (size > resp->len) {
+		rc = -EIO;
+		goto error;
+	}
+
+	skb_pull(resp, size);
+
 	switch (DIGITAL_NFC_DEP_PFB_TYPE(pfb)) {
 	case DIGITAL_NFC_DEP_PFB_I_PDU:
 		if (DIGITAL_NFC_DEP_PFB_PNI(pfb) != ddev->curr_nfc_dep_pni) {
@@ -435,7 +445,7 @@ static void digital_in_recv_dep_res(struct nfc_digital_dev *ddev, void *arg,
 			goto error;
 		}
 
-		rc = digital_in_send_rtox(ddev, data_exch, resp->data[3]);
+		rc = digital_in_send_rtox(ddev, data_exch, resp->data[0]);
 		if (rc)
 			goto error;
 
@@ -449,18 +459,6 @@ static void digital_in_recv_dep_res(struct nfc_digital_dev *ddev, void *arg,
 		goto error;
 	}
 
-	size = sizeof(struct digital_dep_req_res);
-
-	if (DIGITAL_NFC_DEP_DID_BIT_SET(pfb))
-		size++;
-
-	if (size > resp->len) {
-		rc = -EIO;
-		goto error;
-	}
-
-	skb_pull(resp, size);
-
 exit:
 	data_exch->cb(data_exch->cb_context, resp, rc);
 
@@ -524,6 +522,7 @@ static void digital_tg_recv_dep_req(struct nfc_digital_dev *ddev, void *arg,
 {
 	int rc;
 	struct digital_dep_req_res *dep_req;
+	u8 pfb;
 	size_t size;
 
 	if (IS_ERR(resp)) {
@@ -553,18 +552,22 @@ static void digital_tg_recv_dep_req(struct nfc_digital_dev *ddev, void *arg,
 		goto exit;
 	}
 
-	if (DIGITAL_NFC_DEP_DID_BIT_SET(dep_req->pfb))
+	pfb = dep_req->pfb;
+
+	if (DIGITAL_NFC_DEP_DID_BIT_SET(pfb))
 		size++;
 
-	if (resp->len < size) {
+	if (size > resp->len) {
 		rc = -EIO;
 		goto exit;
 	}
 
-	switch (DIGITAL_NFC_DEP_PFB_TYPE(dep_req->pfb)) {
+	skb_pull(resp, size);
+
+	switch (DIGITAL_NFC_DEP_PFB_TYPE(pfb)) {
 	case DIGITAL_NFC_DEP_PFB_I_PDU:
 		pr_debug("DIGITAL_NFC_DEP_PFB_I_PDU\n");
-		ddev->curr_nfc_dep_pni = DIGITAL_NFC_DEP_PFB_PNI(dep_req->pfb);
+		ddev->curr_nfc_dep_pni = DIGITAL_NFC_DEP_PFB_PNI(pfb);
 		break;
 	case DIGITAL_NFC_DEP_PFB_ACK_NACK_PDU:
 		pr_err("Received a ACK/NACK PDU\n");
@@ -576,8 +579,6 @@ static void digital_tg_recv_dep_req(struct nfc_digital_dev *ddev, void *arg,
 		goto exit;
 	}
 
-	skb_pull(resp, size);
-
 	rc = nfc_tm_data_received(ddev->nfc_dev, resp);
 
 exit: