net: cdc_ncm: split out rx_max/tx_max update of setup

Split out the part of setup dealing with updating the rx_max
and tx_max buffer sizes so that this code can be reused for
dynamically updating the limits.

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

diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c
index d23bca5..e5f5153 100644 (file)
--- a/drivers/net/usb/cdc_ncm.c
+++ b/drivers/net/usb/cdc_ncm.c
@@ -65,6 +65,61 @@ static void cdc_ncm_tx_timeout_start(struct cdc_ncm_ctx *ctx);
 static enum hrtimer_restart cdc_ncm_tx_timer_cb(struct hrtimer *hr_timer);
 static struct usb_driver cdc_ncm_driver;
 
+/* handle rx_max and tx_max changes */
+static void cdc_ncm_update_rxtx_max(struct usbnet *dev, u32 new_rx, u32 new_tx)
+{
+       struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
+       u8 iface_no = ctx->control->cur_altsetting->desc.bInterfaceNumber;
+       u32 val, max, min;
+
+       /* clamp new_rx to sane values */
+       min = USB_CDC_NCM_NTB_MIN_IN_SIZE;
+       max = min_t(u32, CDC_NCM_NTB_MAX_SIZE_RX, le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize));
+
+       /* dwNtbInMaxSize spec violation? Use MIN size for both limits */
+       if (max < min) {
+               dev_warn(&dev->intf->dev, "dwNtbInMaxSize=%u is too small. Using %u\n",
+                        le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize), min);
+               max = min;
+       }
+
+       val = clamp_t(u32, new_rx, min, max);
+       if (val != new_rx) {
+               dev_dbg(&dev->intf->dev, "rx_max must be in the [%u, %u] range. Using %u\n",
+                       min, max, 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);
+               if (usbnet_write_cmd(dev, USB_CDC_SET_NTB_INPUT_SIZE,
+                                    USB_TYPE_CLASS | USB_DIR_OUT
+                                    | USB_RECIP_INTERFACE,
+                                    0, iface_no, &dwNtbInMaxSize, 4) < 0)
+                       dev_dbg(&dev->intf->dev, "Setting NTB Input Size failed\n");
+               else
+                       ctx->rx_max = val;
+       }
+
+       /* clamp new_tx to sane values */
+       min = CDC_NCM_MIN_HDR_SIZE + ctx->max_datagram_size;
+       max = min_t(u32, CDC_NCM_NTB_MAX_SIZE_TX, le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize));
+
+       /* some devices set dwNtbOutMaxSize too low for the above default */
+       min = min(min, max);
+
+       val = clamp_t(u32, new_tx, min, max);
+       if (val != new_tx) {
+               dev_dbg(&dev->intf->dev, "tx_max must be in the [%u, %u] range. Using %u\n",
+                       min, max, val);
+       }
+       if (val != ctx->tx_max)
+               dev_info(&dev->intf->dev, "setting tx_max = %u\n", val);
+       ctx->tx_max = val;
+}
+
 static int cdc_ncm_setup(struct usbnet *dev)
 {
        struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
@@ -132,37 +187,8 @@ static int cdc_ncm_setup(struct usbnet *dev)
                        (ctx->tx_max_datagrams > CDC_NCM_DPT_DATAGRAMS_MAX))
                ctx->tx_max_datagrams = CDC_NCM_DPT_DATAGRAMS_MAX;
 
-       /* verify maximum size of received NTB in bytes */
-       if (ctx->rx_max < USB_CDC_NCM_NTB_MIN_IN_SIZE) {
-               dev_dbg(&dev->intf->dev, "Using min receive length=%d\n",
-                       USB_CDC_NCM_NTB_MIN_IN_SIZE);
-               ctx->rx_max = USB_CDC_NCM_NTB_MIN_IN_SIZE;
-       }
-
-       if (ctx->rx_max > CDC_NCM_NTB_MAX_SIZE_RX) {
-               dev_dbg(&dev->intf->dev, "Using default maximum receive length=%d\n",
-                       CDC_NCM_NTB_MAX_SIZE_RX);
-               ctx->rx_max = CDC_NCM_NTB_MAX_SIZE_RX;
-       }
-
-       /* inform device about NTB input size changes */
-       if (ctx->rx_max != le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize)) {
-               __le32 dwNtbInMaxSize = cpu_to_le32(ctx->rx_max);
-
-               err = usbnet_write_cmd(dev, USB_CDC_SET_NTB_INPUT_SIZE,
-                                      USB_TYPE_CLASS | USB_DIR_OUT
-                                      | USB_RECIP_INTERFACE,
-                                      0, iface_no, &dwNtbInMaxSize, 4);
-               if (err < 0)
-                       dev_dbg(&dev->intf->dev, "Setting NTB Input Size failed\n");
-       }
-
-       /* verify maximum size of transmitted NTB in bytes */
-       if (ctx->tx_max > CDC_NCM_NTB_MAX_SIZE_TX) {
-               dev_dbg(&dev->intf->dev, "Using default maximum transmit length=%d\n",
-                       CDC_NCM_NTB_MAX_SIZE_TX);
-               ctx->tx_max = CDC_NCM_NTB_MAX_SIZE_TX;
-       }
+       /* clamp rx_max and tx_max and inform device */
+       cdc_ncm_update_rxtx_max(dev, le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize), le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize));
 
        /*
         * verify that the structure alignment is: