korina: rework korina_rx() for use with napi

This function needs an early exit condition to function properly, or
else caller assumes napi workload wasn't enough to handle all received
packets and korina_rx is called again (and again and again and ...).

Signed-off-by: Phil Sutter <n0-1@freewrt.org>
Acked-by: Florian Fainelli <florian@openwrt.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 53 insertions, 56 deletions

diff --git a/drivers/net/korina.c b/drivers/net/korina.c
index 65b8487c1896..a1d8af7d0bcd 100644
--- a/drivers/net/korina.c
+++ b/drivers/net/korina.c
@@ -353,15 +353,20 @@ static int korina_rx(struct net_device *dev, int limit)
         struct dma_desc *rd = &lp->rd_ring[lp->rx_next_done];
         struct sk_buff *skb, *skb_new;
         u8 *pkt_buf;
-        u32 devcs, pkt_len, dmas, rx_free_desc;
+        u32 devcs, pkt_len, dmas;
         int count;
 
         dma_cache_inv((u32)rd, sizeof(*rd));
 
         for (count = 0; count < limit; count++) {
+                skb = lp->rx_skb[lp->rx_next_done];
+                skb_new = NULL;
 
                 devcs = rd->devcs;
 
+                if ((KORINA_RBSIZE - (u32)DMA_COUNT(rd->control)) == 0)
+                        break;
+
                 /* Update statistics counters */
                 if (devcs & ETH_RX_CRC)
                         dev->stats.rx_crc_errors++;
@@ -384,63 +389,55 @@ static int korina_rx(struct net_device *dev, int limit)
                          * in Rc32434 (errata ref #077) */
                         dev->stats.rx_errors++;
                         dev->stats.rx_dropped++;
-                }
-
-                while ((rx_free_desc = KORINA_RBSIZE - (u32)DMA_COUNT(rd->control)) != 0) {
-                        /* init the var. used for the later
-                         * operations within the while loop */
-                        skb_new = NULL;
+                } else if ((devcs & ETH_RX_ROK)) {
                         pkt_len = RCVPKT_LENGTH(devcs);
-                        skb = lp->rx_skb[lp->rx_next_done];
-
-                        if ((devcs & ETH_RX_ROK)) {
-                                /* must be the (first and) last
-                                 * descriptor then */
-                                pkt_buf = (u8 *)lp->rx_skb[lp->rx_next_done]->data;
-
-                                /* invalidate the cache */
-                                dma_cache_inv((unsigned long)pkt_buf, pkt_len - 4);
-
-                                /* Malloc up new buffer. */
-                                skb_new = netdev_alloc_skb(dev, KORINA_RBSIZE + 2);
-
-                                if (!skb_new)
-                                        break;
-                                /* Do not count the CRC */
-                                skb_put(skb, pkt_len - 4);
-                                skb->protocol = eth_type_trans(skb, dev);
-
-                                /* Pass the packet to upper layers */
-                                netif_receive_skb(skb);
-                                dev->stats.rx_packets++;
-                                dev->stats.rx_bytes += pkt_len;
-
-                                /* Update the mcast stats */
-                                if (devcs & ETH_RX_MP)
-                                        dev->stats.multicast++;
-
-                                lp->rx_skb[lp->rx_next_done] = skb_new;
-                        }
-
-                        rd->devcs = 0;
-
-                        /* Restore descriptor's curr_addr */
-                        if (skb_new)
-                                rd->ca = CPHYSADDR(skb_new->data);
-                        else
-                                rd->ca = CPHYSADDR(skb->data);
-
-                        rd->control = DMA_COUNT(KORINA_RBSIZE) |
-                                DMA_DESC_COD | DMA_DESC_IOD;
-                        lp->rd_ring[(lp->rx_next_done - 1) &
-                                KORINA_RDS_MASK].control &=
-                                ~DMA_DESC_COD;
-
-                        lp->rx_next_done = (lp->rx_next_done + 1) & KORINA_RDS_MASK;
-                        dma_cache_wback((u32)rd, sizeof(*rd));
-                        rd = &lp->rd_ring[lp->rx_next_done];
-                        writel(~DMA_STAT_DONE, &lp->rx_dma_regs->dmas);
+
+                        /* must be the (first and) last
+                         * descriptor then */
+                        pkt_buf = (u8 *)lp->rx_skb[lp->rx_next_done]->data;
+
+                        /* invalidate the cache */
+                        dma_cache_inv((unsigned long)pkt_buf, pkt_len - 4);
+
+                        /* Malloc up new buffer. */
+                        skb_new = netdev_alloc_skb(dev, KORINA_RBSIZE + 2);
+
+                        if (!skb_new)
+                                break;
+                        /* Do not count the CRC */
+                        skb_put(skb, pkt_len - 4);
+                        skb->protocol = eth_type_trans(skb, dev);
+
+                        /* Pass the packet to upper layers */
+                        netif_receive_skb(skb);
+                        dev->stats.rx_packets++;
+                        dev->stats.rx_bytes += pkt_len;
+
+                        /* Update the mcast stats */
+                        if (devcs & ETH_RX_MP)
+                                dev->stats.multicast++;
+
+                        lp->rx_skb[lp->rx_next_done] = skb_new;
                 }
+
+                rd->devcs = 0;
+
+                /* Restore descriptor's curr_addr */
+                if (skb_new)
+                        rd->ca = CPHYSADDR(skb_new->data);
+                else
+                        rd->ca = CPHYSADDR(skb->data);
+
+                rd->control = DMA_COUNT(KORINA_RBSIZE) |
+                        DMA_DESC_COD | DMA_DESC_IOD;
+                lp->rd_ring[(lp->rx_next_done - 1) &
+                        KORINA_RDS_MASK].control &=
+                        ~DMA_DESC_COD;
+
+                lp->rx_next_done = (lp->rx_next_done + 1) & KORINA_RDS_MASK;
+                dma_cache_wback((u32)rd, sizeof(*rd));
+                rd = &lp->rd_ring[lp->rx_next_done];
+                writel(~DMA_STAT_DONE, &lp->rx_dma_regs->dmas);
         }
 
         dmas = readl(&lp->rx_dma_regs->dmas);