usb: cdc-acm: send zero packet for intel 7260 modem
For Intel 7260 modem, it is needed for host side to send zero
packet if the BULK OUT size is equal to USB endpoint max packet
length. Otherwise, modem side may still wait for more data and
cannot give response to host side.
Signed-off-by: Konrad Leszczynski <konrad.leszczynski@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 8cd193b..e4c70dc 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -1405,6 +1405,8 @@
usb_sndbulkpipe(usb_dev, epwrite->bEndpointAddress),
NULL, acm->writesize, acm_write_bulk, snd);
snd->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
+ if (quirks & SEND_ZERO_PACKET)
+ snd->urb->transfer_flags |= URB_ZERO_PACKET;
snd->instance = acm;
}
@@ -1862,6 +1864,10 @@
{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
USB_CDC_ACM_PROTO_AT_CDMA) },
+ { USB_DEVICE(0x1519, 0x0452), /* Intel 7260 modem */
+ .driver_info = SEND_ZERO_PACKET,
+ },
+
{ }
};
diff --git a/drivers/usb/class/cdc-acm.h b/drivers/usb/class/cdc-acm.h
index dd9af38..ccfaba9 100644
--- a/drivers/usb/class/cdc-acm.h
+++ b/drivers/usb/class/cdc-acm.h
@@ -134,3 +134,4 @@
#define IGNORE_DEVICE BIT(5)
#define QUIRK_CONTROL_LINE_STATE BIT(6)
#define CLEAR_HALT_CONDITIONS BIT(7)
+#define SEND_ZERO_PACKET BIT(8)