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    igb: Remove superfluous reset to PHY and page 0 selection · 8c9e873c
    Christian Grönke authored
    [ Upstream commit 2a83fba6cae89dd9c0625e68ff8ffff791c67ac0 ]
    
    This patch reverts two previous applied patches to fix an issue
    that appeared when using SGMII based SFP modules. In the current
    state the driver will try to reset the PHY before obtaining the
    phy_addr of the SGMII attached PHY. That leads to an error in
    e1000_write_phy_reg_sgmii_82575. Causing the initialization to
    fail:
    
        igb: Intel(R) Gigabit Ethernet Network Driver - version 5.4.0-k
        igb: Copyright (c) 2007-2014 Intel Corporation.
        igb: probe of ????:??:??.? failed with error -3
    
    The patches being reverted are:
    
        commit 18278533
        Author: Aaron Sierra <asierra@xes-inc.com>
        Date:   Tue Nov 29 10:03:56 2016 -0600
    
            igb: reset the PHY before reading the PHY ID
    
        commit 440aeca4
        Author: Matwey V Kornilov <matwey@sai.msu.ru>
        Date:   Thu Nov 24 13:32:48 2016 +0300
    
             igb: Explicitly select page 0 at initialization
    
    The first reverted patch directly causes the problem mentioned above.
    In case of SGMII the phy_addr is not known at this point and will
    only be obtained by 'igb_get_phy_id_82575' further down in the code.
    The second removed patch selects forces selection of page 0 in the
    PHY. Something that the reset tries to address as well.
    
    As pointed out by Alexander Duzck, the patch below fixes the same
    issue but in the proper location:
    
        commit 4e684f59
        Author: Chris J Arges <christopherarges@gmail.com>
        Date:   Wed Nov 2 09:13:42 2016 -0500
    
            igb: Workaround for igb i210 firmware issue
    
    Reverts: 440aeca4.
    Reverts: 18278533
    
    .
    
    Signed-off-by: default avatarChristian Grönke <c.groenke@infodas.de>
    Reviewed-by: default avatarAlexander Duyck <alexander.h.duyck@intel.com>
    Tested-by: default avatarAaron Brown <aaron.f.brown@intel.com>
    Signed-off-by: default avatarJeff Kirsher <jeffrey.t.kirsher@intel.com>
    Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
    8c9e873c