4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Francois Romieu <romieu@xxxxxxxxxxxxx> [ Upstream commit a78e93661c5fd30b9e1dee464b2f62f966883ef7 ] 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 <romieu@xxxxxxxxxxxxx> Tested-by: Oliver Freyermuth <o.freyermuth@xxxxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/ethernet/realtek/r8169.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) --- a/drivers/net/ethernet/realtek/r8169.c +++ b/drivers/net/ethernet/realtek/r8169.c @@ -2205,19 +2205,14 @@ static bool rtl8169_do_counters(struct n 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)