[PATCH 2.6.8-rc3-mm1 1/2] 8139too: Rx fifo/overflow recovery
From: Francois Romieu <romieu@fr.zoreil.com>
Date: 2004-08-05 21:43:36
This patch allows to update the interrupt status register after an Rx overflow or a Rx fifo error even when the Rx buffer contains no packet. As a side effect it saves a few heavy (i.e. flushed) pci ops per received packet when several packets are received at the same time. Signed-off-by: Francois Romieu <romieu@fr.zoreil.com> diff -puN drivers/net/8139too.c~r8139-10 drivers/net/8139too.c
--- linux-2.6.8-rc3/drivers/net/8139too.c~r8139-10 2004-08-05 23:09:26.000000000 +0200
+++ linux-2.6.8-rc3-romieu/drivers/net/8139too.c 2004-08-05 23:14:31.000000000 +0200@@ -1934,12 +1934,15 @@ static int rtl8139_rx(struct net_device int received = 0; unsigned char *rx_ring = tp->rx_ring; unsigned int cur_rx = tp->cur_rx; + u16 status; DPRINTK ("%s: In rtl8139_rx(), current %4.4x BufAddr %4.4x," " free to %4.4x, Cmd %2.2x.\n", dev->name, cur_rx, RTL_R16 (RxBufAddr), RTL_R16 (RxBufPtr), RTL_R8 (ChipCmd)); + status = RTL_R16 (IntrStatus) & RxAckBits; + while (netif_running(dev) && received < budget && (RTL_R8 (ChipCmd) & RxBufEmpty) == 0) { u32 ring_offset = cur_rx % RX_BUF_LEN;
@@ -1947,7 +1950,6 @@ static int rtl8139_rx(struct net_device unsigned int rx_size; unsigned int pkt_size; struct sk_buff *skb; - u16 status; rmb();
@@ -1977,7 +1979,7 @@ static int rtl8139_rx(struct net_device */ if (unlikely(rx_size == 0xfff0)) { tp->xstats.early_rx++; - goto done; + break; } /* If Rx err or invalid rx_size/rx_status received
@@ -1989,7 +1991,8 @@ static int rtl8139_rx(struct net_device (rx_size < 8) || (!(rx_status & RxStatusOK)))) { rtl8139_rx_err (rx_status, dev, tp, ioaddr); - return -1; + received = -1; + goto out; } /* Malloc up new buffer, compatible with net-2e. */
@@ -2024,21 +2027,18 @@ static int rtl8139_rx(struct net_device cur_rx = (cur_rx + rx_size + 4 + 3) & ~3; RTL_W16 (RxBufPtr, (u16) (cur_rx - 16)); + } - /* Clear out errors and receive interrupts */ - status = RTL_R16 (IntrStatus) & RxAckBits; - if (likely(status != 0)) { - if (unlikely(status & (RxFIFOOver | RxOverflow))) { - tp->stats.rx_errors++; - if (status & RxFIFOOver) - tp->stats.rx_fifo_errors++; - } - RTL_W16_F (IntrStatus, RxAckBits); + /* Clear out errors and receive interrupts */ + if (likely(status != 0)) { + if (unlikely(status & (RxFIFOOver | RxOverflow))) { + tp->stats.rx_errors++; + if (status & RxFIFOOver) + tp->stats.rx_fifo_errors++; } + RTL_W16_F (IntrStatus, RxAckBits); } - done: - #if RTL8139_DEBUG > 1 DPRINTK ("%s: Done rtl8139_rx(), current %4.4x BufAddr %4.4x," " free to %4.4x, Cmd %2.2x.\n", dev->name, cur_rx,
@@ -2047,6 +2047,7 @@ static int rtl8139_rx(struct net_device #endif tp->cur_rx = cur_rx; +out: return received; }
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