From a78e93661c5fd30b9e1dee464b2f62f966883ef7 Mon Sep 17 00:00:00 2001 From: Francois Romieu Date: Fri, 26 Jan 2018 01:53:26 +0100 Subject: [PATCH] r8169: fix memory corruption on retrieval of hardware statistics. Hardware statistics retrieval hurts in tight invocation loops. Avoid extraneous write and enforce strict ordering of writes targeted to the tally counters dump area address registers. Signed-off-by: Francois Romieu Tested-by: Oliver Freyermuth Signed-off-by: David S. Miller --- drivers/net/ethernet/realtek/r8169.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) diff --git a/drivers/net/ethernet/realtek/r8169.c b/drivers/net/ethernet/realtek/r8169.c index fc0d5fa65ad4..734286ebe5ef 100644 --- a/drivers/net/ethernet/realtek/r8169.c +++ b/drivers/net/ethernet/realtek/r8169.c @@ -2244,19 +2244,14 @@ static bool rtl8169_do_counters(struct net_device *dev, u32 counter_cmd) void __iomem *ioaddr = tp->mmio_addr; dma_addr_t paddr = tp->counters_phys_addr; u32 cmd; - bool ret; RTL_W32(CounterAddrHigh, (u64)paddr >> 32); + RTL_R32(CounterAddrHigh); cmd = (u64)paddr & DMA_BIT_MASK(32); RTL_W32(CounterAddrLow, cmd); RTL_W32(CounterAddrLow, cmd | counter_cmd); - ret = rtl_udelay_loop_wait_low(tp, &rtl_counters_cond, 10, 1000); - - RTL_W32(CounterAddrLow, 0); - RTL_W32(CounterAddrHigh, 0); - - return ret; + return rtl_udelay_loop_wait_low(tp, &rtl_counters_cond, 10, 1000); } static bool rtl8169_reset_counters(struct net_device *dev) -- 2.30.2