staging: wfx: fix access to le32 attribute 'len'

Sparse complains about the accesses to the field 'len' from struct hif_msg:

    drivers/staging/wfx/bh.c:88:32: warning: restricted __le16 degrades to integer
    drivers/staging/wfx/bh.c:88:32: warning: restricted __le16 degrades to integer
    drivers/staging/wfx/bh.c:93:32: warning: restricted __le16 degrades to integer
    drivers/staging/wfx/bh.c:93:32: warning: cast to restricted __le16
    drivers/staging/wfx/bh.c:93:32: warning: restricted __le16 degrades to integer
    drivers/staging/wfx/bh.c:121:25: warning: incorrect type in argument 2 (different base types)
    drivers/staging/wfx/bh.c:121:25:    expected unsigned int len
    drivers/staging/wfx/bh.c:121:25:    got restricted __le16 [usertype] len
    drivers/staging/wfx/hif_rx.c:27:22: warning: restricted __le16 degrades to integer
    drivers/staging/wfx/hif_rx.c:347:39: warning: incorrect type in argument 7 (different base types)
    drivers/staging/wfx/hif_rx.c:347:39:    expected unsigned int [usertype] len
    drivers/staging/wfx/hif_rx.c:347:39:    got restricted __le16 const [usertype] len
    drivers/staging/wfx/hif_rx.c:365:39: warning: incorrect type in argument 7 (different base types)
    drivers/staging/wfx/hif_rx.c:365:39:    expected unsigned int [usertype] len
    drivers/staging/wfx/hif_rx.c:365:39:    got restricted __le16 const [usertype] len
    drivers/staging/wfx/./traces.h:195:1: warning: incorrect type in assignment (different base types)
    drivers/staging/wfx/./traces.h:195:1:    expected int msg_len
    drivers/staging/wfx/./traces.h:195:1:    got restricted __le16 const [usertype] len
    drivers/staging/wfx/./traces.h:195:1: warning: incorrect type in assignment (different base types)
    drivers/staging/wfx/./traces.h:195:1:    expected int msg_len
    drivers/staging/wfx/./traces.h:195:1:    got restricted __le16 const [usertype] len
    drivers/staging/wfx/debug.c:319:20: warning: restricted __le16 degrades to integer
    drivers/staging/wfx/secure_link.c:85:27: warning: restricted __le16 degrades to integer
    drivers/staging/wfx/secure_link.c:85:27: warning: restricted __le16 degrades to integer

Indeed, the attribute len is little-endian. We have to take to the
endianness when we access it.
Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20200512150414.267198-14-Jerome.Pouiller@silabs.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/wfx/bh.c

@@ -84,13 +84,12 @@ static int rx_helper(struct wfx_dev *wdev, size_t read_len, int *is_cnf)
 			// piggyback is probably correct.
 			return piggyback;
 		}
-		le16_to_cpus(&hif->len);
-		computed_len = round_up(hif->len - sizeof(hif->len), 16)
-			       + sizeof(struct hif_sl_msg)
-			       + sizeof(struct hif_sl_tag);
+		computed_len =
+			round_up(le16_to_cpu(hif->len) - sizeof(hif->len), 16) +
+			sizeof(struct hif_sl_msg) +
+			sizeof(struct hif_sl_tag);
 	} else {
-		le16_to_cpus(&hif->len);
-		computed_len = round_up(hif->len, 2);
+		computed_len = round_up(le16_to_cpu(hif->len), 2);
 	}
 	if (computed_len != read_len) {
 		dev_err(wdev->dev, "inconsistent message length: %zu != %zu\n",
@@ -118,7 +117,7 @@ static int rx_helper(struct wfx_dev *wdev, size_t read_len, int *is_cnf)
 		wdev->hif.rx_seqnum = (hif->seqnum + 1) % (HIF_COUNTER_MAX + 1);
 	}
 
-	skb_put(skb, hif->len);
+	skb_put(skb, le16_to_cpu(hif->len));
 	// wfx_handle_rx takes care on SKB livetime
 	wfx_handle_rx(wdev, skb);
 	if (!wdev->hif.tx_buffers_used)

drivers/staging/wfx/debug.c

@@ -250,7 +250,7 @@ static ssize_t wfx_send_hif_msg_write(struct file *file,
 	request = memdup_user(user_buf, count);
 	if (IS_ERR(request))
 		return PTR_ERR(request);
-	if (request->len != count) {
+	if (le16_to_cpu(request->len) != count) {
 		kfree(request);
 		return -EINVAL;
 	}

drivers/staging/wfx/hif_rx.c

@@ -24,7 +24,7 @@ static int hif_generic_confirm(struct wfx_dev *wdev,
 	// All confirm messages start with status
 	int status = le32_to_cpup((__le32 *)buf);
 	int cmd = hif->id;
-	int len = hif->len - 4; // drop header
+	int len = le16_to_cpu(hif->len) - 4; // drop header
 
 	WARN(!mutex_is_locked(&wdev->hif_cmd.lock), "data locking error");
 
@@ -348,7 +348,7 @@ static int hif_error_indication(struct wfx_dev *wdev,
 	else
 		dev_err(wdev->dev, "asynchronous error: unknown: %08x\n", type);
 	print_hex_dump(KERN_INFO, "hif: ", DUMP_PREFIX_OFFSET,
-		       16, 1, hif, hif->len, false);
+		       16, 1, hif, le16_to_cpu(hif->len), false);
 	wdev->chip_frozen = true;
 
 	return 0;
@@ -366,7 +366,7 @@ static int hif_exception_indication(struct wfx_dev *wdev,
 	else
 		dev_err(wdev->dev, "firmware exception\n");
 	print_hex_dump(KERN_INFO, "hif: ", DUMP_PREFIX_OFFSET,
-		       16, 1, hif, hif->len, false);
+		       16, 1, hif, le16_to_cpu(hif->len), false);
 	wdev->chip_frozen = true;
 
 	return -1;

drivers/staging/wfx/traces.h

@@ -174,7 +174,7 @@ DECLARE_EVENT_CLASS(hif_data,
 		int header_len;
 
 		__entry->tx_fill_level = tx_fill_level;
-		__entry->msg_len = hif->len;
+		__entry->msg_len = le16_to_cpu(hif->len);
 		__entry->msg_id = hif->id;
 		__entry->if_id = hif->interface;
 		if (is_recv)