4.9-stable review patch. If anyone has any objections, please let me know.
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From: Francois Romieu romieu@fr.zoreil.com
[ 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@fr.zoreil.com Tested-by: Oliver Freyermuth o.freyermuth@googlemail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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 @@ -2222,19 +2222,14 @@ 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)