[PATCH 4.4 16/28] USB: serial: option: add ZLP support for 0x1bc7/0x9010

From: Greg Kroah-Hartman
Date: Tue Jan 14 2020 - 05:13:34 EST


From: Daniele Palmas <dnlplm@xxxxxxxxx>

commit 2438c3a19dec5e98905fd3ffcc2f24716aceda6b upstream.

Telit FN980 flashing device 0x1bc7/0x9010 requires zero packet
to be sent if out data size is is equal to the endpoint max size.

Signed-off-by: Daniele Palmas <dnlplm@xxxxxxxxx>
[ johan: switch operands in conditional ]
Cc: stable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/usb/serial/option.c | 8 ++++++++
drivers/usb/serial/usb-wwan.h | 1 +
drivers/usb/serial/usb_wwan.c | 4 ++++
3 files changed, 13 insertions(+)

--- a/drivers/usb/serial/option.c
+++ b/drivers/usb/serial/option.c
@@ -566,6 +566,9 @@ static void option_instat_callback(struc
/* Interface is reserved */
#define RSVD(ifnum) ((BIT(ifnum) & 0xff) << 0)

+/* Device needs ZLP */
+#define ZLP BIT(17)
+

static const struct usb_device_id option_ids[] = {
{ USB_DEVICE(OPTION_VENDOR_ID, OPTION_PRODUCT_COLT) },
@@ -1193,6 +1196,8 @@ static const struct usb_device_id option
.driver_info = NCTRL(0) | RSVD(1) },
{ USB_DEVICE_INTERFACE_CLASS(TELIT_VENDOR_ID, 0x1901, 0xff), /* Telit LN940 (MBIM) */
.driver_info = NCTRL(0) },
+ { USB_DEVICE(TELIT_VENDOR_ID, 0x9010), /* Telit SBL FN980 flashing device */
+ .driver_info = NCTRL(0) | ZLP },
{ USB_DEVICE_AND_INTERFACE_INFO(ZTE_VENDOR_ID, ZTE_PRODUCT_MF622, 0xff, 0xff, 0xff) }, /* ZTE WCDMA products */
{ USB_DEVICE_AND_INTERFACE_INFO(ZTE_VENDOR_ID, 0x0002, 0xff, 0xff, 0xff),
.driver_info = RSVD(1) },
@@ -2097,6 +2102,9 @@ static int option_attach(struct usb_seri
if (!(device_flags & NCTRL(iface_desc->bInterfaceNumber)))
data->use_send_setup = 1;

+ if (device_flags & ZLP)
+ data->use_zlp = 1;
+
spin_lock_init(&data->susp_lock);

usb_set_serial_data(serial, data);
--- a/drivers/usb/serial/usb-wwan.h
+++ b/drivers/usb/serial/usb-wwan.h
@@ -35,6 +35,7 @@ struct usb_wwan_intf_private {
spinlock_t susp_lock;
unsigned int suspended:1;
unsigned int use_send_setup:1;
+ unsigned int use_zlp:1;
int in_flight;
unsigned int open_ports;
void *private;
--- a/drivers/usb/serial/usb_wwan.c
+++ b/drivers/usb/serial/usb_wwan.c
@@ -495,6 +495,7 @@ static struct urb *usb_wwan_setup_urb(st
void (*callback) (struct urb *))
{
struct usb_serial *serial = port->serial;
+ struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);
struct urb *urb;

urb = usb_alloc_urb(0, GFP_KERNEL); /* No ISO */
@@ -505,6 +506,9 @@ static struct urb *usb_wwan_setup_urb(st
usb_sndbulkpipe(serial->dev, endpoint) | dir,
buf, len, callback, ctx);

+ if (intfdata->use_zlp && dir == USB_DIR_OUT)
+ urb->transfer_flags |= URB_ZERO_PACKET;
+
return urb;
}