#include "emac.h"
+static void arc_emac_restart(struct net_device *ndev);
+
/**
* arc_emac_tx_avail - Return the number of available slots in the tx ring.
* @priv: Pointer to ARC EMAC private data structure.
continue;
}
- pktlen = info & LEN_MASK;
- stats->rx_packets++;
- stats->rx_bytes += pktlen;
- skb = rx_buff->skb;
- skb_put(skb, pktlen);
- skb->dev = ndev;
- skb->protocol = eth_type_trans(skb, ndev);
-
- dma_unmap_single(&ndev->dev, dma_unmap_addr(rx_buff, addr),
- dma_unmap_len(rx_buff, len), DMA_FROM_DEVICE);
-
- /* Prepare the BD for next cycle */
- rx_buff->skb = netdev_alloc_skb_ip_align(ndev,
- EMAC_BUFFER_SIZE);
- if (unlikely(!rx_buff->skb)) {
+ /* Prepare the BD for next cycle. netif_receive_skb()
+ * only if new skb was allocated and mapped to avoid holes
+ * in the RX fifo.
+ */
+ skb = netdev_alloc_skb_ip_align(ndev, EMAC_BUFFER_SIZE);
+ if (unlikely(!skb)) {
+ if (net_ratelimit())
+ netdev_err(ndev, "cannot allocate skb\n");
+ /* Return ownership to EMAC */
+ rxbd->info = cpu_to_le32(FOR_EMAC | EMAC_BUFFER_SIZE);
stats->rx_errors++;
- /* Because receive_skb is below, increment rx_dropped */
stats->rx_dropped++;
continue;
}
- /* receive_skb only if new skb was allocated to avoid holes */
- netif_receive_skb(skb);
-
- addr = dma_map_single(&ndev->dev, (void *)rx_buff->skb->data,
+ addr = dma_map_single(&ndev->dev, (void *)skb->data,
EMAC_BUFFER_SIZE, DMA_FROM_DEVICE);
if (dma_mapping_error(&ndev->dev, addr)) {
if (net_ratelimit())
- netdev_err(ndev, "cannot dma map\n");
- dev_kfree_skb(rx_buff->skb);
+ netdev_err(ndev, "cannot map dma buffer\n");
+ dev_kfree_skb(skb);
+ /* Return ownership to EMAC */
+ rxbd->info = cpu_to_le32(FOR_EMAC | EMAC_BUFFER_SIZE);
stats->rx_errors++;
+ stats->rx_dropped++;
continue;
}
+
+ /* unmap previosly mapped skb */
+ dma_unmap_single(&ndev->dev, dma_unmap_addr(rx_buff, addr),
+ dma_unmap_len(rx_buff, len), DMA_FROM_DEVICE);
+
+ pktlen = info & LEN_MASK;
+ stats->rx_packets++;
+ stats->rx_bytes += pktlen;
+ skb_put(rx_buff->skb, pktlen);
+ rx_buff->skb->dev = ndev;
+ rx_buff->skb->protocol = eth_type_trans(rx_buff->skb, ndev);
+
+ netif_receive_skb(rx_buff->skb);
+
+ rx_buff->skb = skb;
dma_unmap_addr_set(rx_buff, addr, addr);
dma_unmap_len_set(rx_buff, len, EMAC_BUFFER_SIZE);
return work_done;
}
+/**
+ * arc_emac_rx_miss_handle - handle R_MISS register
+ * @ndev: Pointer to the net_device structure.
+ */
+static void arc_emac_rx_miss_handle(struct net_device *ndev)
+{
+ struct arc_emac_priv *priv = netdev_priv(ndev);
+ struct net_device_stats *stats = &ndev->stats;
+ unsigned int miss;
+
+ miss = arc_reg_get(priv, R_MISS);
+ if (miss) {
+ stats->rx_errors += miss;
+ stats->rx_missed_errors += miss;
+ priv->rx_missed_errors += miss;
+ }
+}
+
+/**
+ * arc_emac_rx_stall_check - check RX stall
+ * @ndev: Pointer to the net_device structure.
+ * @budget: How many BDs requested to process on 1 call.
+ * @work_done: How many BDs processed
+ *
+ * Under certain conditions EMAC stop reception of incoming packets and
+ * continuously increment R_MISS register instead of saving data into
+ * provided buffer. This function detect that condition and restart
+ * EMAC.
+ */
+static void arc_emac_rx_stall_check(struct net_device *ndev,
+ int budget, unsigned int work_done)
+{
+ struct arc_emac_priv *priv = netdev_priv(ndev);
+ struct arc_emac_bd *rxbd;
+
+ if (work_done)
+ priv->rx_missed_errors = 0;
+
+ if (priv->rx_missed_errors && budget) {
+ rxbd = &priv->rxbd[priv->last_rx_bd];
+ if (le32_to_cpu(rxbd->info) & FOR_EMAC) {
+ arc_emac_restart(ndev);
+ priv->rx_missed_errors = 0;
+ }
+ }
+}
+
/**
* arc_emac_poll - NAPI poll handler.
* @napi: Pointer to napi_struct structure.
unsigned int work_done;
arc_emac_tx_clean(ndev);
+ arc_emac_rx_miss_handle(ndev);
work_done = arc_emac_rx(ndev, budget);
if (work_done < budget) {
arc_reg_or(priv, R_ENABLE, RXINT_MASK | TXINT_MASK);
}
+ arc_emac_rx_stall_check(ndev, budget, work_done);
+
return work_done;
}
if (status & MSER_MASK) {
stats->rx_missed_errors += 0x100;
stats->rx_errors += 0x100;
+ priv->rx_missed_errors += 0x100;
+ napi_schedule(&priv->napi);
}
if (status & RXCR_MASK) {
}
+/**
+ * arc_emac_restart - Restart EMAC
+ * @ndev: Pointer to net_device structure.
+ *
+ * This function do hardware reset of EMAC in order to restore
+ * network packets reception.
+ */
+static void arc_emac_restart(struct net_device *ndev)
+{
+ struct arc_emac_priv *priv = netdev_priv(ndev);
+ struct net_device_stats *stats = &ndev->stats;
+ int i;
+
+ if (net_ratelimit())
+ netdev_warn(ndev, "restarting stalled EMAC\n");
+
+ netif_stop_queue(ndev);
+
+ /* Disable interrupts */
+ arc_reg_clr(priv, R_ENABLE, RXINT_MASK | TXINT_MASK | ERR_MASK);
+
+ /* Disable EMAC */
+ arc_reg_clr(priv, R_CTRL, EN_MASK);
+
+ /* Return the sk_buff to system */
+ arc_free_tx_queue(ndev);
+
+ /* Clean Tx BD's */
+ priv->txbd_curr = 0;
+ priv->txbd_dirty = 0;
+ memset(priv->txbd, 0, TX_RING_SZ);
+
+ for (i = 0; i < RX_BD_NUM; i++) {
+ struct arc_emac_bd *rxbd = &priv->rxbd[i];
+ unsigned int info = le32_to_cpu(rxbd->info);
+
+ if (!(info & FOR_EMAC)) {
+ stats->rx_errors++;
+ stats->rx_dropped++;
+ }
+ /* Return ownership to EMAC */
+ rxbd->info = cpu_to_le32(FOR_EMAC | EMAC_BUFFER_SIZE);
+ }
+ priv->last_rx_bd = 0;
+
+ /* Make sure info is visible to EMAC before enable */
+ wmb();
+
+ /* Enable interrupts */
+ arc_reg_set(priv, R_ENABLE, RXINT_MASK | TXINT_MASK | ERR_MASK);
+
+ /* Enable EMAC */
+ arc_reg_or(priv, R_CTRL, EN_MASK);
+
+ netif_start_queue(ndev);
+}
+
static const struct net_device_ops arc_emac_netdev_ops = {
.ndo_open = arc_emac_open,
.ndo_stop = arc_emac_stop,
git.samba.org / sfrench / cifs-2.6.git / blobdiff