Patch "igb: reset the PHY before reading the PHY ID" has been added to the 4.9-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    igb: reset the PHY before reading the PHY ID

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     igb-reset-the-phy-before-reading-the-phy-id.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Sun Nov 19 11:32:28 CET 2017
From: Aaron Sierra <asierra@xes-inc.com>
Date: Tue, 29 Nov 2016 10:03:56 -0600
Subject: igb: reset the PHY before reading the PHY ID

From: Aaron Sierra <asierra@xes-inc.com>


[ Upstream commit 182785335447957409282ca745aa5bc3968facee ]

Several people have reported firmware leaving the I210/I211 PHY's page
select register set to something other than the default of zero. This
causes the first accesses, PHY_IDx register reads, to access something
else, resulting in device probe failure:

    igb: Intel(R) Gigabit Ethernet Network Driver - version 5.4.0-k
    igb: Copyright (c) 2007-2014 Intel Corporation.
    igb: probe of 0000:01:00.0 failed with error -2

This problem began for them after a previous patch I submitted was
applied:

    commit 2a3cdead8b408351fa1e3079b220fa331480ffbc
    Author: Aaron Sierra <asierra@xes-inc.com>
    Date:   Tue Nov 3 12:37:09 2015 -0600

        igb: Remove GS40G specific defines/functions

I personally experienced this problem after attempting to PXE boot from
I210 devices using this firmware:

    Intel(R) Boot Agent GE v1.5.78
    Copyright (C) 1997-2014, Intel Corporation

Resetting the PHY before reading from it, ensures the page select
register is in its default state and doesn't make assumptions about
the PHY's register set before the PHY has been probed.

Cc: Matwey V. Kornilov <matwey@sai.msu.ru>
Cc: Chris Arges <carges@vectranetworks.com>
Cc: Jochen Henneberg <jh@henneberg-systemdesign.com>
Signed-off-by: Aaron Sierra <asierra@xes-inc.com>
Tested-by: Matwey V. Kornilov <matwey@sai.msu.ru>
Tested-by: Chris J Arges <christopherarges@gmail.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/net/ethernet/intel/igb/e1000_82575.c |   11 +++++++++++
 1 file changed, 11 insertions(+)

--- a/drivers/net/ethernet/intel/igb/e1000_82575.c
+++ b/drivers/net/ethernet/intel/igb/e1000_82575.c
@@ -245,6 +245,17 @@ static s32 igb_init_phy_params_82575(str
 	hw->bus.func = (rd32(E1000_STATUS) & E1000_STATUS_FUNC_MASK) >>
 			E1000_STATUS_FUNC_SHIFT;
 
+	/* Make sure the PHY is in a good state. Several people have reported
+	 * firmware leaving the PHY's page select register set to something
+	 * other than the default of zero, which causes the PHY ID read to
+	 * access something other than the intended register.
+	 */
+	ret_val = hw->phy.ops.reset(hw);
+	if (ret_val) {
+		hw_dbg("Error resetting the PHY.\n");
+		goto out;
+	}
+
 	/* Set phy->phy_addr and phy->id. */
 	igb_write_phy_reg_82580(hw, I347AT4_PAGE_SELECT, 0);
 	ret_val = igb_get_phy_id_82575(hw);


Patches currently in stable-queue which might be from asierra@xes-inc.com are

queue-4.9/igb-reset-the-phy-before-reading-the-phy-id.patch