1 files changed, 42 insertions, 27 deletions

diff --git a/drivers/net/can/usb/kvaser_usb.c b/drivers/net/can/usb/kvaser_usb.c
index e97a08ce0b90..57611fd91229 100644
--- a/drivers/net/can/usb/kvaser_usb.c
+++ b/drivers/net/can/usb/kvaser_usb.c
@@ -25,7 +25,6 @@
 #include <linux/can/dev.h>
 #include <linux/can/error.h>
 
-#define MAX_TX_URBS                     16
 #define MAX_RX_URBS                     4
 #define START_TIMEOUT                   1000 /* msecs */
 #define STOP_TIMEOUT                    1000 /* msecs */
@@ -443,6 +442,7 @@ struct kvaser_usb_error_summary {
         };
 };
 
+/* Context for an outstanding, not yet ACKed, transmission */
 struct kvaser_usb_tx_urb_context {
         struct kvaser_usb_net_priv *priv;
         u32 echo_index;
@@ -456,8 +456,13 @@ struct kvaser_usb {
         struct usb_endpoint_descriptor *bulk_in, *bulk_out;
         struct usb_anchor rx_submitted;
 
+        /* @max_tx_urbs: Firmware-reported maximum number of oustanding,
+         * not yet ACKed, transmissions on this device. This value is
+         * also used as a sentinel for marking free tx contexts.
+         */
         u32 fw_version;
         unsigned int nchannels;
+        unsigned int max_tx_urbs;
         enum kvaser_usb_family family;
 
         bool rxinitdone;
@@ -467,19 +472,18 @@ struct kvaser_usb {
 
 struct kvaser_usb_net_priv {
         struct can_priv can;
-
-        spinlock_t tx_contexts_lock;
-        int active_tx_contexts;
-        struct kvaser_usb_tx_urb_context tx_contexts[MAX_TX_URBS];
-
-        struct usb_anchor tx_submitted;
-        struct completion start_comp, stop_comp;
+        struct can_berr_counter bec;
 
         struct kvaser_usb *dev;
         struct net_device *netdev;
         int channel;
 
-        struct can_berr_counter bec;
+        struct completion start_comp, stop_comp;
+        struct usb_anchor tx_submitted;
+
+        spinlock_t tx_contexts_lock;
+        int active_tx_contexts;
+        struct kvaser_usb_tx_urb_context tx_contexts[];
 };
 
 static const struct usb_device_id kvaser_usb_table[] = {
@@ -592,8 +596,8 @@ static int kvaser_usb_wait_msg(const struct kvaser_usb *dev, u8 id,
                          * for further details.
                          */
                         if (tmp->len == 0) {
-                                pos = round_up(pos,
-                                               dev->bulk_in->wMaxPacketSize);
+                                pos = round_up(pos, le16_to_cpu(dev->bulk_in->
+                                                                wMaxPacketSize));
                                 continue;
                         }
 
@@ -657,9 +661,13 @@ static int kvaser_usb_get_software_info(struct kvaser_usb *dev)
         switch (dev->family) {
         case KVASER_LEAF:
                 dev->fw_version = le32_to_cpu(msg.u.leaf.softinfo.fw_version);
+                dev->max_tx_urbs =
+                        le16_to_cpu(msg.u.leaf.softinfo.max_outstanding_tx);
                 break;
         case KVASER_USBCAN:
                 dev->fw_version = le32_to_cpu(msg.u.usbcan.softinfo.fw_version);
+                dev->max_tx_urbs =
+                        le16_to_cpu(msg.u.usbcan.softinfo.max_outstanding_tx);
                 break;
         }
 
@@ -715,7 +723,7 @@ static void kvaser_usb_tx_acknowledge(const struct kvaser_usb *dev,
 
         stats = &priv->netdev->stats;
 
-        context = &priv->tx_contexts[tid % MAX_TX_URBS];
+        context = &priv->tx_contexts[tid % dev->max_tx_urbs];
 
         /* Sometimes the state change doesn't come after a bus-off event */
         if (priv->can.restart_ms &&
@@ -744,7 +752,7 @@ static void kvaser_usb_tx_acknowledge(const struct kvaser_usb *dev,
         spin_lock_irqsave(&priv->tx_contexts_lock, flags);
 
         can_get_echo_skb(priv->netdev, context->echo_index);
-        context->echo_index = MAX_TX_URBS;
+        context->echo_index = dev->max_tx_urbs;
         --priv->active_tx_contexts;
         netif_wake_queue(priv->netdev);
 
@@ -1329,7 +1337,8 @@ static void kvaser_usb_read_bulk_callback(struct urb *urb)
                  * number of events in case of a heavy rx load on the bus.
                  */
                 if (msg->len == 0) {
-                        pos = round_up(pos, dev->bulk_in->wMaxPacketSize);
+                        pos = round_up(pos, le16_to_cpu(dev->bulk_in->
+                                                        wMaxPacketSize));
                         continue;
                 }
 
@@ -1512,11 +1521,13 @@ error:
 
 static void kvaser_usb_reset_tx_urb_contexts(struct kvaser_usb_net_priv *priv)
 {
-        int i;
+        int i, max_tx_urbs;
+
+        max_tx_urbs = priv->dev->max_tx_urbs;
 
         priv->active_tx_contexts = 0;
-        for (i = 0; i < MAX_TX_URBS; i++)
-                priv->tx_contexts[i].echo_index = MAX_TX_URBS;
+        for (i = 0; i < max_tx_urbs; i++)
+                priv->tx_contexts[i].echo_index = max_tx_urbs;
 }
 
 /* This method might sleep. Do not call it in the atomic context
@@ -1702,14 +1713,14 @@ static netdev_tx_t kvaser_usb_start_xmit(struct sk_buff *skb,
                 *msg_tx_can_flags |= MSG_FLAG_REMOTE_FRAME;
 
         spin_lock_irqsave(&priv->tx_contexts_lock, flags);
-        for (i = 0; i < ARRAY_SIZE(priv->tx_contexts); i++) {
-                if (priv->tx_contexts[i].echo_index == MAX_TX_URBS) {
+        for (i = 0; i < dev->max_tx_urbs; i++) {
+                if (priv->tx_contexts[i].echo_index == dev->max_tx_urbs) {
                         context = &priv->tx_contexts[i];
 
                         context->echo_index = i;
                         can_put_echo_skb(skb, netdev, context->echo_index);
                         ++priv->active_tx_contexts;
-                        if (priv->active_tx_contexts >= MAX_TX_URBS)
+                        if (priv->active_tx_contexts >= dev->max_tx_urbs)
                                 netif_stop_queue(netdev);
 
                         break;
@@ -1743,7 +1754,7 @@ static netdev_tx_t kvaser_usb_start_xmit(struct sk_buff *skb,
                 spin_lock_irqsave(&priv->tx_contexts_lock, flags);
 
                 can_free_echo_skb(netdev, context->echo_index);
-                context->echo_index = MAX_TX_URBS;
+                context->echo_index = dev->max_tx_urbs;
                 --priv->active_tx_contexts;
                 netif_wake_queue(netdev);
 
@@ -1881,7 +1892,9 @@ static int kvaser_usb_init_one(struct usb_interface *intf,
         if (err)
                 return err;
 
-        netdev = alloc_candev(sizeof(*priv), MAX_TX_URBS);
+        netdev = alloc_candev(sizeof(*priv) +
+                              dev->max_tx_urbs * sizeof(*priv->tx_contexts),
+                              dev->max_tx_urbs);
         if (!netdev) {
                 dev_err(&intf->dev, "Cannot alloc candev\n");
                 return -ENOMEM;
@@ -2009,6 +2022,13 @@ static int kvaser_usb_probe(struct usb_interface *intf,
                 return err;
         }
 
+        dev_dbg(&intf->dev, "Firmware version: %d.%d.%d\n",
+                ((dev->fw_version >> 24) & 0xff),
+                ((dev->fw_version >> 16) & 0xff),
+                (dev->fw_version & 0xffff));
+
+        dev_dbg(&intf->dev, "Max oustanding tx = %d URBs\n", dev->max_tx_urbs);
+
         err = kvaser_usb_get_card_info(dev);
         if (err) {
                 dev_err(&intf->dev,
@@ -2016,11 +2036,6 @@ static int kvaser_usb_probe(struct usb_interface *intf,
                 return err;
         }
 
-        dev_dbg(&intf->dev, "Firmware version: %d.%d.%d\n",
-                ((dev->fw_version >> 24) & 0xff),
-                ((dev->fw_version >> 16) & 0xff),
-                (dev->fw_version & 0xffff));
-
         for (i = 0; i < dev->nchannels; i++) {
                 err = kvaser_usb_init_one(intf, id, i);
                 if (err) {