[PATCH 3.2 016/101] USB: serial: ti_usb_3410_5052: fix control-message error handling

From: Ben Hutchings
Date: Thu Jun 01 2017 - 13:07:36 EST


3.2.89-rc1 review patch. If anyone has any objections, please let me know.

------------------

From: Johan Hovold <johan@xxxxxxxxxx>

commit 39712e8bfa8d3aa6ce1e60fc9d62c9b076c17a30 upstream.

Make sure to detect and return an error on zero-length control-message
transfers when reading from the device.

This addresses a potential failure to detect an empty transmit buffer
during close.

Also remove a redundant check for short transfer when sending a command.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
drivers/usb/serial/ti_usb_3410_5052.c | 12 ++++--------
1 file changed, 4 insertions(+), 8 deletions(-)

--- a/drivers/usb/serial/ti_usb_3410_5052.c
+++ b/drivers/usb/serial/ti_usb_3410_5052.c
@@ -1614,13 +1614,10 @@ static int ti_command_out_sync(struct ti
(USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT),
value, moduleid, data, size, 1000);

- if (status == size)
- status = 0;
-
- if (status > 0)
- status = -ECOMM;
+ if (status < 0)
+ return status;

- return status;
+ return 0;
}


@@ -1636,8 +1633,7 @@ static int ti_command_in_sync(struct ti_

if (status == size)
status = 0;
-
- if (status > 0)
+ else if (status >= 0)
status = -ECOMM;

return status;