[PATCH 4.14 09/27] usb: cdc-acm: send ZLP for Telit 3G Intel based modems

From: Greg Kroah-Hartman
Date: Tue Jan 15 2019 - 11:41:06 EST


4.14-stable review patch. If anyone has any objections, please let me know.

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

From: Daniele Palmas <dnlplm@xxxxxxxxx>

commit 34aabf918717dd14e05051896aaecd3b16b53d95 upstream.

Telit 3G Intel based modems require zero packet to be sent if
out data size is equal to the endpoint max packet size.

Signed-off-by: Daniele Palmas <dnlplm@xxxxxxxxx>
Cc: stable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/usb/class/cdc-acm.c | 7 +++++++
1 file changed, 7 insertions(+)

--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -1893,6 +1893,13 @@ static const struct usb_device_id acm_id
.driver_info = IGNORE_DEVICE,
},

+ { USB_DEVICE(0x1bc7, 0x0021), /* Telit 3G ACM only composition */
+ .driver_info = SEND_ZERO_PACKET,
+ },
+ { USB_DEVICE(0x1bc7, 0x0023), /* Telit 3G ACM + ECM composition */
+ .driver_info = SEND_ZERO_PACKET,
+ },
+
/* control interfaces without any protocol set */
{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
USB_CDC_PROTO_NONE) },