From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:51210 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1423878AbeCBI4k (ORCPT ); Fri, 2 Mar 2018 03:56:40 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Fredrik Hallenberg , "David S. Miller" , Sasha Levin Subject: [PATCH 4.9 21/56] net: stmmac: Fix TX timestamp calculation Date: Fri, 2 Mar 2018 09:51:07 +0100 Message-Id: <20180302084450.674988291@linuxfoundation.org> In-Reply-To: <20180302084449.568562222@linuxfoundation.org> References: <20180302084449.568562222@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: Fredrik Hallenberg [ Upstream commit 200922c93f008e03ddc804c6dacdf26ca1ba86d7 ] When using GMAC4 the value written in PTP_SSIR should be shifted however the shifted value is also used in subsequent calculations which results in a bad timestamp value. Signed-off-by: Fredrik Hallenberg Signed-off-by: David S. Miller Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c @@ -38,6 +38,7 @@ static u32 stmmac_config_sub_second_incr { u32 value = readl(ioaddr + PTP_TCR); unsigned long data; + u32 reg_value; /* For GMAC3.x, 4.x versions, convert the ptp_clock to nano second * formula = (1/ptp_clock) * 1000000000 @@ -54,10 +55,11 @@ static u32 stmmac_config_sub_second_incr data &= PTP_SSIR_SSINC_MASK; + reg_value = data; if (gmac4) - data = data << GMAC4_PTP_SSIR_SSINC_SHIFT; + reg_value <<= GMAC4_PTP_SSIR_SSINC_SHIFT; - writel(data, ioaddr + PTP_SSIR); + writel(reg_value, ioaddr + PTP_SSIR); return data; }