net: cdc_ncm: support rx_max/tx_max updates when running

Finish the rx_max/tx_max setup by flushing buffers and
informing usbnet about the changes.  This way, the settings
can be modified while the netdev is up and running.

Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 25 insertions, 6 deletions

diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c
index 7a3de73c8ded..2ec3790a4db8 100644
--- a/drivers/net/usb/cdc_ncm.c
+++ b/drivers/net/usb/cdc_ncm.c
@@ -89,11 +89,20 @@ static void cdc_ncm_update_rxtx_max(struct usbnet *dev, u32 new_rx, u32 new_tx)
                         min, max, val);
         }
 
+        /* usbnet use these values for sizing rx queues */
+        dev->rx_urb_size = val;
+
         /* inform device about NTB input size changes */
         if (val != ctx->rx_max) {
                 __le32 dwNtbInMaxSize = cpu_to_le32(val);
 
                 dev_info(&dev->intf->dev, "setting rx_max = %u\n", val);
+
+                /* need to unlink rx urbs before increasing buffer size */
+                if (netif_running(dev->net) && dev->rx_urb_size > ctx->rx_max)
+                        usbnet_unlink_rx_urbs(dev);
+
+                /* tell device to use new size */
                 if (usbnet_write_cmd(dev, USB_CDC_SET_NTB_INPUT_SIZE,
                                      USB_TYPE_CLASS | USB_DIR_OUT
                                      | USB_RECIP_INTERFACE,
@@ -117,7 +126,6 @@ static void cdc_ncm_update_rxtx_max(struct usbnet *dev, u32 new_rx, u32 new_tx)
         }
         if (val != ctx->tx_max)
                 dev_info(&dev->intf->dev, "setting tx_max = %u\n", val);
-        ctx->tx_max = val;
 
         /* Adding a pad byte here if necessary simplifies the handling
          * in cdc_ncm_fill_tx_frame, making tx_max always represent
@@ -126,13 +134,24 @@ static void cdc_ncm_update_rxtx_max(struct usbnet *dev, u32 new_rx, u32 new_tx)
          * We cannot use dev->maxpacket here because this is called from
          * .bind which is called before usbnet sets up dev->maxpacket
          */
-        if (ctx->tx_max != le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize) &&
-            ctx->tx_max % usb_maxpacket(dev->udev, dev->out, 1) == 0)
-                ctx->tx_max++;
+        if (val != le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize) &&
+            val % usb_maxpacket(dev->udev, dev->out, 1) == 0)
+                val++;
+
+        /* we might need to flush any pending tx buffers if running */
+        if (netif_running(dev->net) && val > ctx->tx_max) {
+                netif_tx_lock_bh(dev->net);
+                usbnet_start_xmit(NULL, dev->net);
+                ctx->tx_max = val;
+                netif_tx_unlock_bh(dev->net);
+        } else {
+                ctx->tx_max = val;
+        }
 
-        /* usbnet use these values for sizing tx/rx queues */
         dev->hard_mtu = ctx->tx_max;
-        dev->rx_urb_size = ctx->rx_max;
+
+        /* max qlen depend on hard_mtu and rx_urb_size */
+        usbnet_update_max_qlen(dev);
 }
 
 /* helpers for NCM and MBIM differences */