usb: cdc-acm: send zero packet for intel 7260 modem

[ Upstream commit ffdb1e369a73b380fce95b05f8498d92c43842b4 ]

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>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 2bf51b2..8bfcf20 100644 (file)
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -1415,6 +1415,8 @@ 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;
        }
 
@@ -1872,6 +1874,10 @@ 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 b3b6c9d..ac830e0 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)