Subject: [PATCH 19/22] net: cdc_ncm: GetNtbFormat endian fix

From: Bjørn Mork <[email-masked]>
Date: Wed, 15 Nov 2017 09:35:02 +0100

[ Upstream commit 6314dab4b8fb8493d810e175cb340376052c69b6 ]

The GetNtbFormat and SetNtbFormat requests operate on 16 bit little
endian values. We get away with ignoring this most of the time, because
we only care about USB_CDC_NCM_NTB16_FORMAT which is 0x0000.  This
fails for USB_CDC_NCM_NTB32_FORMAT.

Fix comparison between LE value from device and constant by converting
the constant to LE.

Reported-by: Ben Hutchings <[email-masked]>
Fixes: 2b02c20ce0c2 ("cdc_ncm: Set NTB format again after altsetting switch for Huawei devices")
Cc: Enrico Mioso <[email-masked]>
Cc: Christian Panton <[email-masked]>
Signed-off-by: Bjørn Mork <[email-masked]>
Acked-By: Enrico Mioso <[email-masked]>
Signed-off-by: David S. Miller <[email-masked]>
---
 drivers/net/usb/cdc_ncm.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c
index 9c80e80c5493..8d5e97251efe 100644
--- a/drivers/net/usb/cdc_ncm.c
+++ b/drivers/net/usb/cdc_ncm.c
@@ -771,7 +771,7 @@ int cdc_ncm_bind_common(struct usbnet *dev, struct usb_interface *intf, u8 data_
 	int err;
 	u8 iface_no;
 	struct usb_cdc_parsed_header hdr;
-	u16 curr_ntb_format;
+	__le16 curr_ntb_format;
 
 	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
 	if (!ctx)
@@ -889,7 +889,7 @@ int cdc_ncm_bind_common(struct usbnet *dev, struct usb_interface *intf, u8 data_
 			goto error2;
 		}
 
-		if (curr_ntb_format == USB_CDC_NCM_NTB32_FORMAT) {
+		if (curr_ntb_format == cpu_to_le16(USB_CDC_NCM_NTB32_FORMAT)) {
 			dev_info(&intf->dev, "resetting NTB format to 16-bit");
 			err = usbnet_write_cmd(dev, USB_CDC_SET_NTB_FORMAT,
 					       USB_TYPE_CLASS | USB_DIR_OUT
-- 
2.13.6