USB: io_ti: check firmware version before updating

commit 0827a9ff2bbcbb03c33f1a6eb283fe051059482c upstream.

If we can't read the firmware for a device from the disk, and yet the
device already has a valid firmware image in it, we don't want to
replace the firmware with something invalid.  So check the version
number to be less than the current one to verify this is the correct
thing to do.

Reported-by: Chris Beauchamp <chris@chillibean.tv>
Tested-by: Chris Beauchamp <chris@chillibean.tv>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/serial/io_ti.c b/drivers/usb/serial/io_ti.c
index 0fca265..9991063 100644 (file)
--- a/drivers/usb/serial/io_ti.c
+++ b/drivers/usb/serial/io_ti.c
@@ -1151,7 +1151,7 @@ static int download_fw(struct edgeport_serial *serial)
 
                        /* Check if we have an old version in the I2C and
                           update if necessary */
-                       if (download_cur_ver != download_new_ver) {
+                       if (download_cur_ver < download_new_ver) {
                                dbg("%s - Update I2C dld from %d.%d to %d.%d",
                                    __func__,
                                    firmware_version->Ver_Major,