USB: io_ti: fix firmware download on big-endian machines (part 2)

commit c03890ff upstream.

A recent patch that purported to fix firmware download on big-endian
machines failed to add the corresponding sparse annotation to the
i2c-header. This was reported by the kbuild test robot.

Adding the appropriate annotation revealed another endianess bug related
to the i2c-header Size-field in a code path that is exercised when the
firmware is actually being downloaded (and not just verified and left
untouched unless older than the firmware at hand).

This patch adds the required sparse annotation to the i2c-header and
makes sure that the Size-field is sent in little-endian byte order
during firmware download also on big-endian machines.

Note that this patch is only compile-tested, but that there is no
functional change for little-endian systems.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Cc: Ludovic Drolez <ldrolez@debian.org>
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

drivers/usb/serial/io_ti.c

@@ -923,7 +923,7 @@ static int build_i2c_fw_hdr(__u8 *header, struct device *dev)
 	firmware_rec =  (struct ti_i2c_firmware_rec*)i2c_header->Data;
 
 	i2c_header->Type	= I2C_DESC_TYPE_FIRMWARE_BLANK;
-	i2c_header->Size	= (__u16)buffer_size;
+	i2c_header->Size	= cpu_to_le16(buffer_size);
 	i2c_header->CheckSum	= cs;
 	firmware_rec->Ver_Major	= OperationalMajorVersion;
 	firmware_rec->Ver_Minor	= OperationalMinorVersion;

drivers/usb/serial/io_usbvend.h

@@ -594,7 +594,7 @@ struct edge_boot_descriptor {
 
 struct ti_i2c_desc {
 	__u8	Type;			// Type of descriptor
-	__u16	Size;			// Size of data only not including header
+	__le16	Size;			// Size of data only not including header
 	__u8	CheckSum;		// Checksum (8 bit sum of data only)
 	__u8	Data[0];		// Data starts here
 } __attribute__((packed));