staging: wfx: fix display of exception indication

Until now, the exception received from the chip was only displayed if
driver was compiled with DEBUG enabled. It was not very convenient to
help users. We prefer to show the exception unconditionally.

In add, this patch provides the semantic of the first bytes of the
struct.
Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20200427134031.323403-17-Jerome.Pouiller@silabs.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/wfx/hif_api_general.h

@@ -223,12 +223,6 @@ struct hif_ind_generic {
 	union hif_indication_data indication_data;
 } __packed;
 
-
-struct hif_ind_exception {
-	u8     data[124];
-} __packed;
-
-
 enum hif_error {
 	HIF_ERROR_FIRMWARE_ROLLBACK       = 0x0,
 	HIF_ERROR_FIRMWARE_DEBUG_ENABLED  = 0x1,
@@ -248,6 +242,11 @@ struct hif_ind_error {
 	u8     data[];
 } __packed;
 
+struct hif_ind_exception {
+	__le32 type;
+	u8     data[];
+} __packed;
+
 enum hif_secure_link_state {
 	SEC_LINK_UNAVAILABLE = 0x0,
 	SEC_LINK_RESERVED    = 0x1,

drivers/staging/wfx/hif_rx.c

@@ -331,10 +331,16 @@ static int hif_generic_indication(struct wfx_dev *wdev,
 static int hif_exception_indication(struct wfx_dev *wdev,
 				    const struct hif_msg *hif, const void *buf)
 {
-	size_t len = hif->len - 4; // drop header
+	const struct hif_ind_exception *body = buf;
+	int type = le32_to_cpu(body->type);
 
-	dev_err(wdev->dev, "firmware exception\n");
-	print_hex_dump_bytes("Dump: ", DUMP_PREFIX_NONE, buf, len);
+	if (type == 4)
+		dev_err(wdev->dev, "firmware assert %d\n",
+			le32_to_cpup((__le32 *)body->data));
+	else
+		dev_err(wdev->dev, "firmware exception\n");
+	print_hex_dump(KERN_INFO, "hif: ", DUMP_PREFIX_OFFSET,
+		       16, 1, hif, hif->len, false);
 	wdev->chip_frozen = true;
 
 	return -1;