From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:42754 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932371AbeA2UP0 (ORCPT ); Mon, 29 Jan 2018 15:15:26 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Francois Romieu , Oliver Freyermuth , "David S. Miller" Subject: [PATCH 4.9 42/66] r8169: fix memory corruption on retrieval of hardware statistics. Date: Mon, 29 Jan 2018 13:57:06 +0100 Message-Id: <20180129123842.099325529@linuxfoundation.org> In-Reply-To: <20180129123839.842860149@linuxfoundation.org> References: <20180129123839.842860149@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Francois Romieu [ 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 Tested-by: Oliver Freyermuth Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- 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)