drivers: net: usb: pegasus: remove skb pool

The socket buffer pool for the receive path is now gone.  It's existence
didn't make much difference (performance-wise) and the code is better off
without the spinlocks protecting it.

Signed-off-by: Petko Manolov <petkan@nucleusys.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 9 insertions, 67 deletions

diff --git a/drivers/net/usb/pegasus.c b/drivers/net/usb/pegasus.c
index 73051d10ead2..ff7b84d4c9fd 100644
--- a/drivers/net/usb/pegasus.c
+++ b/drivers/net/usb/pegasus.c
@@ -575,51 +575,6 @@ static int enable_net_traffic(struct net_device *dev, struct usb_device *usb)
         return ret;
 }
 
-static void fill_skb_pool(pegasus_t *pegasus)
-{
-        int i;
-
-        for (i = 0; i < RX_SKBS; i++) {
-                if (pegasus->rx_pool[i])
-                        continue;
-                pegasus->rx_pool[i] = dev_alloc_skb(PEGASUS_MTU + 2);
-                /*
-                 ** we give up if the allocation fail. the tasklet will be
-                 ** rescheduled again anyway...
-                 */
-                if (pegasus->rx_pool[i] == NULL)
-                        return;
-                skb_reserve(pegasus->rx_pool[i], 2);
-        }
-}
-
-static void free_skb_pool(pegasus_t *pegasus)
-{
-        int i;
-
-        for (i = 0; i < RX_SKBS; i++) {
-                if (pegasus->rx_pool[i]) {
-                        dev_kfree_skb(pegasus->rx_pool[i]);
-                        pegasus->rx_pool[i] = NULL;
-                }
-        }
-}
-
-static inline struct sk_buff *pull_skb(pegasus_t * pegasus)
-{
-        int i;
-        struct sk_buff *skb;
-
-        for (i = 0; i < RX_SKBS; i++) {
-                if (likely(pegasus->rx_pool[i] != NULL)) {
-                        skb = pegasus->rx_pool[i];
-                        pegasus->rx_pool[i] = NULL;
-                        return skb;
-                }
-        }
-        return NULL;
-}
-
 static void read_bulk_callback(struct urb *urb)
 {
         pegasus_t *pegasus = urb->context;
@@ -704,9 +659,8 @@ static void read_bulk_callback(struct urb *urb)
         if (pegasus->flags & PEGASUS_UNPLUG)
                 return;
 
-        spin_lock(&pegasus->rx_pool_lock);
-        pegasus->rx_skb = pull_skb(pegasus);
-        spin_unlock(&pegasus->rx_pool_lock);
+        pegasus->rx_skb = __netdev_alloc_skb_ip_align(pegasus->net, PEGASUS_MTU,
+                                                      GFP_ATOMIC);
 
         if (pegasus->rx_skb == NULL)
                 goto tl_sched;
@@ -734,24 +688,23 @@ tl_sched:
 static void rx_fixup(unsigned long data)
 {
         pegasus_t *pegasus;
-        unsigned long flags;
         int status;
 
         pegasus = (pegasus_t *) data;
         if (pegasus->flags & PEGASUS_UNPLUG)
                 return;
 
-        spin_lock_irqsave(&pegasus->rx_pool_lock, flags);
-        fill_skb_pool(pegasus);
         if (pegasus->flags & PEGASUS_RX_URB_FAIL)
                 if (pegasus->rx_skb)
                         goto try_again;
         if (pegasus->rx_skb == NULL)
-                pegasus->rx_skb = pull_skb(pegasus);
+                pegasus->rx_skb = __netdev_alloc_skb_ip_align(pegasus->net,
+                                                              PEGASUS_MTU,
+                                                              GFP_ATOMIC);
         if (pegasus->rx_skb == NULL) {
                 netif_warn(pegasus, rx_err, pegasus->net, "low on memory\n");
                 tasklet_schedule(&pegasus->rx_tl);
-                goto done;
+                return;
         }
         usb_fill_bulk_urb(pegasus->rx_urb, pegasus->usb,
                           usb_rcvbulkpipe(pegasus->usb, 1),
@@ -767,8 +720,6 @@ try_again:
         } else {
                 pegasus->flags &= ~PEGASUS_RX_URB_FAIL;
         }
-done:
-        spin_unlock_irqrestore(&pegasus->rx_pool_lock, flags);
 }
 
 static void write_bulk_callback(struct urb *urb)
@@ -1007,10 +958,9 @@ static int pegasus_open(struct net_device *net)
         int res;
 
         if (pegasus->rx_skb == NULL)
-                pegasus->rx_skb = pull_skb(pegasus);
-        /*
-         ** Note: no point to free the pool.  it is empty :-)
-         */
+                pegasus->rx_skb = __netdev_alloc_skb_ip_align(pegasus->net,
+                                                              PEGASUS_MTU,
+                                                              GFP_KERNEL);
         if (!pegasus->rx_skb)
                 return -ENOMEM;
 
@@ -1044,7 +994,6 @@ static int pegasus_open(struct net_device *net)
                 res = -EIO;
                 usb_kill_urb(pegasus->rx_urb);
                 usb_kill_urb(pegasus->intr_urb);
-                free_skb_pool(pegasus);
                 goto exit;
         }
         set_carrier(net);
@@ -1364,7 +1313,6 @@ static int pegasus_probe(struct usb_interface *intf,
         pegasus->mii.mdio_write = mdio_write;
         pegasus->mii.phy_id_mask = 0x1f;
         pegasus->mii.reg_num_mask = 0x1f;
-        spin_lock_init(&pegasus->rx_pool_lock);
         pegasus->msg_enable = netif_msg_init(msg_level, NETIF_MSG_DRV
                                 | NETIF_MSG_PROBE | NETIF_MSG_LINK);
 
@@ -1376,7 +1324,6 @@ static int pegasus_probe(struct usb_interface *intf,
                 goto out2;
         }
         set_ethernet_addr(pegasus);
-        fill_skb_pool(pegasus);
         if (pegasus->features & PEGASUS_II) {
                 dev_info(&intf->dev, "setup Pegasus II specific registers\n");
                 setup_pegasus_II(pegasus);
@@ -1404,7 +1351,6 @@ static int pegasus_probe(struct usb_interface *intf,
 
 out3:
         usb_set_intfdata(intf, NULL);
-        free_skb_pool(pegasus);
 out2:
         free_all_urbs(pegasus);
 out1:
@@ -1429,7 +1375,6 @@ static void pegasus_disconnect(struct usb_interface *intf)
         unregister_netdev(pegasus->net);
         unlink_all_urbs(pegasus);
         free_all_urbs(pegasus);
-        free_skb_pool(pegasus);
         if (pegasus->rx_skb != NULL) {
                 dev_kfree_skb(pegasus->rx_skb);
                 pegasus->rx_skb = NULL;
diff --git a/drivers/net/usb/pegasus.h b/drivers/net/usb/pegasus.h
index 65b78b35b73c..00d44e3ff744 100644
--- a/drivers/net/usb/pegasus.h
+++ b/drivers/net/usb/pegasus.h
@@ -13,7 +13,6 @@
 #define HAS_HOME_PNA            0x40000000
 
 #define PEGASUS_MTU             1536
-#define RX_SKBS                 4
 
 #define EPROM_WRITE             0x01
 #define EPROM_READ              0x02
@@ -97,11 +96,9 @@ typedef struct pegasus {
         struct tasklet_struct   rx_tl;
         struct delayed_work     carrier_check;
         struct urb              *ctrl_urb, *rx_urb, *tx_urb, *intr_urb;
-        struct sk_buff          *rx_pool[RX_SKBS];
         struct sk_buff          *rx_skb;
         struct usb_ctrlrequest  dr;
         wait_queue_head_t       ctrl_wait;
-        spinlock_t              rx_pool_lock;
         int                     chip;
         unsigned char           intr_buff[8];
         __u8                    tx_buff[PEGASUS_MTU];