USB: serial: quatech2: fix control-message error handling
authorJohan Hovold <johan@kernel.org>
Thu, 12 Jan 2017 13:56:20 +0000 (14:56 +0100)
committerJohan Hovold <johan@kernel.org>
Mon, 16 Jan 2017 15:38:56 +0000 (16:38 +0100)
commit8c34cb8ddfe808d557b51da983ff10c02793beb2
tree6e74533df5c17d22996c63e78fb34deb9b42d0b3
parentb5fda434b13de8328c57421e31ac91d401c93b97
USB: serial: quatech2: fix control-message error handling

Make sure to detect short control-message transfers when fetching
modem and line state in open and when retrieving registers.

This specifically makes sure that an errno is returned to user space on
errors in TIOCMGET instead of a zero bitmask.

Also drop the unused getdevice function which also lacked appropriate
error handling.

Fixes: f7a33e608d9a ("USB: serial: add quatech2 usb to serial driver")
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
drivers/usb/serial/quatech2.c