Merge tag 'for-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/kishon/linux...
[deliverable/linux.git] / drivers / net / can / usb / kvaser_usb.c
index a316fa4b91ab20aa0205b5fde1740784495ce6ca..57611fd91229a4580987b3519d56b8913f185411 100644 (file)
@@ -14,6 +14,7 @@
  * Copyright (C) 2015 Valeo S.A.
  */
 
+#include <linux/spinlock.h>
 #include <linux/kernel.h>
 #include <linux/completion.h>
 #include <linux/module.h>
@@ -24,7 +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 */
@@ -442,6 +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;
@@ -455,8 +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;
@@ -466,18 +472,18 @@ struct kvaser_usb {
 
 struct kvaser_usb_net_priv {
        struct can_priv can;
-
-       atomic_t active_tx_urbs;
-       struct usb_anchor tx_submitted;
-       struct kvaser_usb_tx_urb_context tx_contexts[MAX_TX_URBS];
-
-       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[] = {
@@ -590,8 +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;
                        }
 
@@ -655,9 +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;
        }
 
@@ -694,6 +704,7 @@ static void kvaser_usb_tx_acknowledge(const struct kvaser_usb *dev,
        struct kvaser_usb_net_priv *priv;
        struct sk_buff *skb;
        struct can_frame *cf;
+       unsigned long flags;
        u8 channel, tid;
 
        channel = msg->u.tx_acknowledge_header.channel;
@@ -712,7 +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 &&
@@ -737,12 +748,15 @@ static void kvaser_usb_tx_acknowledge(const struct kvaser_usb *dev,
 
        stats->tx_packets++;
        stats->tx_bytes += context->dlc;
-       can_get_echo_skb(priv->netdev, context->echo_index);
 
-       context->echo_index = MAX_TX_URBS;
-       atomic_dec(&priv->active_tx_urbs);
+       spin_lock_irqsave(&priv->tx_contexts_lock, flags);
 
+       can_get_echo_skb(priv->netdev, context->echo_index);
+       context->echo_index = dev->max_tx_urbs;
+       --priv->active_tx_contexts;
        netif_wake_queue(priv->netdev);
+
+       spin_unlock_irqrestore(&priv->tx_contexts_lock, flags);
 }
 
 static void kvaser_usb_simple_msg_callback(struct urb *urb)
@@ -803,17 +817,6 @@ static int kvaser_usb_simple_msg_async(struct kvaser_usb_net_priv *priv,
        return 0;
 }
 
-static void kvaser_usb_unlink_tx_urbs(struct kvaser_usb_net_priv *priv)
-{
-       int i;
-
-       usb_kill_anchored_urbs(&priv->tx_submitted);
-       atomic_set(&priv->active_tx_urbs, 0);
-
-       for (i = 0; i < MAX_TX_URBS; i++)
-               priv->tx_contexts[i].echo_index = MAX_TX_URBS;
-}
-
 static void kvaser_usb_rx_error_update_can_state(struct kvaser_usb_net_priv *priv,
                                                 const struct kvaser_usb_error_summary *es,
                                                 struct can_frame *cf)
@@ -1334,7 +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;
                }
 
@@ -1515,6 +1519,26 @@ error:
        return err;
 }
 
+static void kvaser_usb_reset_tx_urb_contexts(struct kvaser_usb_net_priv *priv)
+{
+       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;
+}
+
+/* This method might sleep. Do not call it in the atomic context
+ * of URB completions.
+ */
+static void kvaser_usb_unlink_tx_urbs(struct kvaser_usb_net_priv *priv)
+{
+       usb_kill_anchored_urbs(&priv->tx_submitted);
+       kvaser_usb_reset_tx_urb_contexts(priv);
+}
+
 static void kvaser_usb_unlink_all_urbs(struct kvaser_usb *dev)
 {
        int i;
@@ -1634,6 +1658,7 @@ static netdev_tx_t kvaser_usb_start_xmit(struct sk_buff *skb,
        struct kvaser_msg *msg;
        int i, err, ret = NETDEV_TX_OK;
        u8 *msg_tx_can_flags = NULL;            /* GCC */
+       unsigned long flags;
 
        if (can_dropped_invalid_skb(netdev, skb))
                return NETDEV_TX_OK;
@@ -1687,12 +1712,21 @@ static netdev_tx_t kvaser_usb_start_xmit(struct sk_buff *skb,
        if (cf->can_id & CAN_RTR_FLAG)
                *msg_tx_can_flags |= MSG_FLAG_REMOTE_FRAME;
 
-       for (i = 0; i < ARRAY_SIZE(priv->tx_contexts); i++) {
-               if (priv->tx_contexts[i].echo_index == MAX_TX_URBS) {
+       spin_lock_irqsave(&priv->tx_contexts_lock, flags);
+       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 >= dev->max_tx_urbs)
+                               netif_stop_queue(netdev);
+
                        break;
                }
        }
+       spin_unlock_irqrestore(&priv->tx_contexts_lock, flags);
 
        /* This should never happen; it implies a flow control bug */
        if (!context) {
@@ -1704,7 +1738,6 @@ static netdev_tx_t kvaser_usb_start_xmit(struct sk_buff *skb,
        }
 
        context->priv = priv;
-       context->echo_index = i;
        context->dlc = cf->can_dlc;
 
        msg->u.tx_can.tid = context->echo_index;
@@ -1716,18 +1749,17 @@ static netdev_tx_t kvaser_usb_start_xmit(struct sk_buff *skb,
                          kvaser_usb_write_bulk_callback, context);
        usb_anchor_urb(urb, &priv->tx_submitted);
 
-       can_put_echo_skb(skb, netdev, context->echo_index);
-
-       atomic_inc(&priv->active_tx_urbs);
-
-       if (atomic_read(&priv->active_tx_urbs) >= MAX_TX_URBS)
-               netif_stop_queue(netdev);
-
        err = usb_submit_urb(urb, GFP_ATOMIC);
        if (unlikely(err)) {
+               spin_lock_irqsave(&priv->tx_contexts_lock, flags);
+
                can_free_echo_skb(netdev, context->echo_index);
+               context->echo_index = dev->max_tx_urbs;
+               --priv->active_tx_contexts;
+               netif_wake_queue(netdev);
+
+               spin_unlock_irqrestore(&priv->tx_contexts_lock, flags);
 
-               atomic_dec(&priv->active_tx_urbs);
                usb_unanchor_urb(urb);
 
                stats->tx_dropped++;
@@ -1854,13 +1886,15 @@ static int kvaser_usb_init_one(struct usb_interface *intf,
        struct kvaser_usb *dev = usb_get_intfdata(intf);
        struct net_device *netdev;
        struct kvaser_usb_net_priv *priv;
-       int i, err;
+       int err;
 
        err = kvaser_usb_send_simple_msg(dev, CMD_RESET_CHIP, channel);
        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;
@@ -1868,19 +1902,17 @@ static int kvaser_usb_init_one(struct usb_interface *intf,
 
        priv = netdev_priv(netdev);
 
+       init_usb_anchor(&priv->tx_submitted);
        init_completion(&priv->start_comp);
        init_completion(&priv->stop_comp);
 
-       init_usb_anchor(&priv->tx_submitted);
-       atomic_set(&priv->active_tx_urbs, 0);
-
-       for (i = 0; i < ARRAY_SIZE(priv->tx_contexts); i++)
-               priv->tx_contexts[i].echo_index = MAX_TX_URBS;
-
        priv->dev = dev;
        priv->netdev = netdev;
        priv->channel = channel;
 
+       spin_lock_init(&priv->tx_contexts_lock);
+       kvaser_usb_reset_tx_urb_contexts(priv);
+
        priv->can.state = CAN_STATE_STOPPED;
        priv->can.clock.freq = CAN_USB_CLOCK;
        priv->can.bittiming_const = &kvaser_usb_bittiming_const;
@@ -1990,6 +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,
@@ -1997,11 +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) {
This page took 0.028898 seconds and 5 git commands to generate.