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>

1 files changed, 57 insertions, 31 deletions

diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c
index d23bca57a23f..e5f5153bf8c6 100644
--- 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: