linux-kernel - [PATCH AUTOSEL for 3.18 22/53] e1000e: fix timing for 82579 Gigabit Ethernet controller

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20180308050230.8876-22-alexander.levin@microsoft.com>
Date:   Thu, 8 Mar 2018 05:03:16 +0000
From:   Sasha Levin <Alexander.Levin@...rosoft.com>
To:     "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "stable@...r.kernel.org" <stable@...r.kernel.org>
CC:     Bernd Faust <berndfaust@...il.com>,
        Jeff Kirsher <jeffrey.t.kirsher@...el.com>,
        Sasha Levin <Alexander.Levin@...rosoft.com>
Subject: [PATCH AUTOSEL for 3.18 22/53] e1000e: fix timing for 82579 Gigabit
 Ethernet controller

From: Bernd Faust <berndfaust@...il.com>

[ Upstream commit 5313eeccd2d7f486be4e5c7560e3e2be239ec8f7 ]

After an upgrade to Linux kernel v4.x the hardware timestamps of the
82579 Gigabit Ethernet Controller are different than expected.
The values that are being read are almost four times as big as before
the kernel upgrade.

The difference is that after the upgrade the driver sets the clock
frequency to 25MHz, where before the upgrade it was set to 96MHz. Intel
confirmed that the correct frequency for this network adapter is 96MHz.

Signed-off-by: Bernd Faust <berndfaust@...il.com>
Acked-by: Sasha Neftin <sasha.neftin@...el.com>
Acked-by: Jacob Keller <jacob.e.keller@...el.com>
Tested-by: Aaron Brown <aaron.f.brown@...el.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@...el.com>
Signed-off-by: Sasha Levin <alexander.levin@...rosoft.com>
---
 drivers/net/ethernet/intel/e1000e/netdev.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index 081dad4e0178..3df8366a8356 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -3507,6 +3507,12 @@ s32 e1000e_get_base_timinca(struct e1000_adapter *adapter, u32 *timinca)
 
 	switch (hw->mac.type) {
 	case e1000_pch2lan:
+		/* Stable 96MHz frequency */
+		incperiod = INCPERIOD_96MHz;
+		incvalue = INCVALUE_96MHz;
+		shift = INCVALUE_SHIFT_96MHz;
+		adapter->cc.shift = shift + INCPERIOD_SHIFT_96MHz;
+		break;
 	case e1000_pch_lpt:
 		/* On I217, the clock frequency is 25MHz or 96MHz as
 		 * indicated by the System Clock Frequency Indication
-- 
2.14.1