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 8cd193bbd04478658703407e98be4bae3614cbc7..e4c70dce3e7cead284d3e86cd69aba840d667e00 100644 (file)
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -1405,6 +1405,8 @@ made_compressed_probe:
                                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 @@ static const struct usb_device_id acm_ids[] = {
        { 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 dd9af38e7cda612106e09c89a298c4397ccf7494..ccfaba9ab4e49cd4a009132397d9467bc949bfd0 100644 (file)
--- a/drivers/usb/class/cdc-acm.h
+++ b/drivers/usb/class/cdc-acm.h
@@ -134,3 +134,4 @@ struct acm {
 #define IGNORE_DEVICE                  BIT(5)
 #define QUIRK_CONTROL_LINE_STATE       BIT(6)
 #define CLEAR_HALT_CONDITIONS          BIT(7)
+#define SEND_ZERO_PACKET               BIT(8)