8139cp: safer spin loop for get_statistics (97f568d8) · Commits · 戴 / test

The spin loop in 8139cp is limited to 100 iterations when pulling hardware stats. There is no allowance for processor speed so on a fast machine, the stats may not be available that fast. Also, if the board doesn't return soon enough make sure turn the address back off to prevent later updates when memory has gone away.

drivers/net/8139cp.c

+6 −6

Original line number	Diff line number	Diff line
		@@ -1516,22 +1516,22 @@ static void cp_get_ethtool_stats (struct net_device *dev,
		struct ethtool_stats estats, u64 tmp_stats)
		{
		struct cp_private *cp = netdev_priv(dev);
		unsigned int work = 100;
		int i;

		memset(cp->nic_stats, 0, sizeof(struct cp_dma_stats));

		/* begin NIC statistics dump */
		cpw32(StatsAddr + 4, (cp->nic_stats_dma >> 16) >> 16);
		cpw32(StatsAddr, (cp->nic_stats_dma & 0xffffffff) \| DumpStats);
		cpr32(StatsAddr);

		while (work-- > 0) {
		for (i = 0; i < 1000; i++) {
		if ((cpr32(StatsAddr) & DumpStats) == 0)
		break;
		cpu_relax();
		udelay(10);
		}

		if (cpr32(StatsAddr) & DumpStats)
		return /* -EIO */;
		cpw32(StatsAddr, 0);
		cpw32(StatsAddr + 4, 0);

		i = 0;
		tmp_stats[i++] = le64_to_cpu(cp->nic_stats->tx_ok);

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