rndis_host: Poll status before control channel where necessary

Some RNDIS devices don't respond on the control channel until polled
on the status channel.  In particular, this was reported to be the
case for the 2Wire HomePortal 1000SW and for some Windows Mobile
devices.

This is roughly based on a patch by John Carr <john.carr@unrouted.co.uk>
which is currently applied by Mandriva.

Reported-by: Mark Glassberg <vzeeaxwl@myfairpoint.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 32 insertions, 7 deletions

diff --git a/drivers/net/usb/rndis_host.c b/drivers/net/usb/rndis_host.c
index 5994a25c56ac..6d6c1da68a36 100644
--- a/drivers/net/usb/rndis_host.c
+++ b/drivers/net/usb/rndis_host.c
@@ -104,8 +104,10 @@ static void rndis_msg_indicate(struct usbnet *dev, struct rndis_indicate *msg,
 int rndis_command(struct usbnet *dev, struct rndis_msg_hdr *buf, int buflen)
 {
         struct cdc_state        *info = (void *) &dev->data;
+        struct usb_cdc_notification notification;
         int                     master_ifnum;
         int                     retval;
+        int                     partial;
         unsigned                count;
         __le32                  rsp;
         u32                     xid = 0, msg_len, request_id;
@@ -133,13 +135,20 @@ int rndis_command(struct usbnet *dev, struct rndis_msg_hdr *buf, int buflen)
         if (unlikely(retval < 0 || xid == 0))
                 return retval;
 
-        // FIXME Seems like some devices discard responses when
-        // we time out and cancel our "get response" requests...
-        // so, this is fragile.  Probably need to poll for status.
+        /* Some devices don't respond on the control channel until
+         * polled on the status channel, so do that first. */
+        if (dev->driver_info->data & RNDIS_DRIVER_DATA_POLL_STATUS) {
+                retval = usb_interrupt_msg(
+                        dev->udev,
+                        usb_rcvintpipe(dev->udev,
+                                       dev->status->desc.bEndpointAddress),
+                        &notification, sizeof(notification), &partial,
+                        RNDIS_CONTROL_TIMEOUT_MS);
+                if (unlikely(retval < 0))
+                        return retval;
+        }
 
-        /* ignore status endpoint, just poll the control channel;
-         * the request probably completed immediately
-         */
+        /* Poll the control channel; the request probably completed immediately */
         rsp = buf->msg_type | RNDIS_MSG_COMPLETION;
         for (count = 0; count < 10; count++) {
                 memset(buf, 0, CONTROL_BUFFER_SIZE);
@@ -581,17 +590,33 @@ static const struct driver_info	rndis_info = {
         .tx_fixup =     rndis_tx_fixup,
 };
 
+static const struct driver_info rndis_poll_status_info = {
+        .description =  "RNDIS device (poll status before control)",
+        .flags =        FLAG_ETHER | FLAG_FRAMING_RN | FLAG_NO_SETINT,
+        .data =         RNDIS_DRIVER_DATA_POLL_STATUS,
+        .bind =         rndis_bind,
+        .unbind =       rndis_unbind,
+        .status =       rndis_status,
+        .rx_fixup =     rndis_rx_fixup,
+        .tx_fixup =     rndis_tx_fixup,
+};
+
 /*-------------------------------------------------------------------------*/
 
 static const struct usb_device_id       products [] = {
 {
+        /* 2Wire HomePortal 1000SW */
+        USB_DEVICE_AND_INTERFACE_INFO(0x1630, 0x0042,
+                                      USB_CLASS_COMM, 2 /* ACM */, 0x0ff),
+        .driver_info = (unsigned long) &rndis_poll_status_info,
+}, {
         /* RNDIS is MSFT's un-official variant of CDC ACM */
         USB_INTERFACE_INFO(USB_CLASS_COMM, 2 /* ACM */, 0x0ff),
         .driver_info = (unsigned long) &rndis_info,
 }, {
         /* "ActiveSync" is an undocumented variant of RNDIS, used in WM5 */
         USB_INTERFACE_INFO(USB_CLASS_MISC, 1, 1),
-        .driver_info = (unsigned long) &rndis_info,
+        .driver_info = (unsigned long) &rndis_poll_status_info,
 }, {
         /* RNDIS for tethering */
         USB_INTERFACE_INFO(USB_CLASS_WIRELESS_CONTROLLER, 1, 3),