Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Sasha Levin <Alexander.Levin@microsoft.com>
To:     "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "stable@vger.kernel.org" <stable@vger.kernel.org>
CC:     Fredrik Hallenberg <megahallon@gmail.com>,
        "David S . Miller" <davem@davemloft.net>,
        Sasha Levin <Alexander.Levin@microsoft.com>
Subject: [PATCH AUTOSEL for 4.14 039/110] net: stmmac: Fix TX timestamp
 calculation
Thread-Topic: [PATCH AUTOSEL for 4.14 039/110] net: stmmac: Fix TX timestamp
 calculation
Thread-Index: AQHTnRjrjhkIDhoz1EyP685HW5XLLw==
Date:   Sat, 3 Feb 2018 18:00:47 +0000
Message-ID: <20180203180015.29073-39-alexander.levin@microsoft.com>
References: <20180203180015.29073-1-alexander.levin@microsoft.com>
In-Reply-To: <20180203180015.29073-1-alexander.levin@microsoft.com>
Accept-Language: en-US
Content-Language: en-US
received-spf: None (protection.outlook.com: microsoft.com does not designate
 permitted sender hosts)
spamdiagnosticoutput: 1:99
spamdiagnosticmetadata: NSPM
Content-Type: text/plain; charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-MS-Exchange-CrossTenant-Network-Message-Id: 78ac9780-4a65-4374-de26-08d56b30218f
X-MS-Exchange-CrossTenant-originalarrivaltime: 03 Feb 2018 18:00:47.4565
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 72f988bf-86f1-41af-91ab-2d7cd011db47
X-MS-Exchange-Transport-CrossTenantHeadersStamped: BL0PR2101MB1092
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

From: Fredrik Hallenberg <megahallon@gmail.com>

[ 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 <megahallon@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c b/driver=
s/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c
index 721b61655261..08c19ebd5306 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c
@@ -34,6 +34,7 @@ static u32 stmmac_config_sub_second_increment(void __iome=
m *ioaddr,
 {
 	u32 value =3D readl(ioaddr + PTP_TCR);
 	unsigned long data;
+	u32 reg_value;
=20
 	/* For GMAC3.x, 4.x versions, convert the ptp_clock to nano second
 	 *	formula =3D (1/ptp_clock) * 1000000000
@@ -50,10 +51,11 @@ static u32 stmmac_config_sub_second_increment(void __io=
mem *ioaddr,
=20
 	data &=3D PTP_SSIR_SSINC_MASK;
=20
+	reg_value =3D data;
 	if (gmac4)
-		data =3D data << GMAC4_PTP_SSIR_SSINC_SHIFT;
+		reg_value <<=3D GMAC4_PTP_SSIR_SSINC_SHIFT;
=20
-	writel(data, ioaddr + PTP_SSIR);
+	writel(reg_value, ioaddr + PTP_SSIR);
=20
 	return data;
 }
--=20
2.11.0