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    Revert "net: mvneta: fix usage as a module on RGMII configurations" · cc6ca302
    Thomas Petazzoni authored
    This reverts commit e3a8786c
    
    . While
    this commit allows to use the mvneta driver as a module on some
    configurations, it breaks other configurations even if mvneta is used
    built-in.
    
    This breakage is due to the fact that on some RGMII platforms, the PCS
    bit has to be set, and on some other platforms, it has to be
    cleared. At the moment, we lack informations to know exactly the
    significance of this bit (the datasheet only says "enables PCS"), and
    so we can't produce a patch that will work on all platforms at this
    point. And since this change is breaking the network completely for
    many users, it's much better to revert it for now. We'll come back
    later with a proper fix that takes into account all platforms.
    
    Basically:
    
     * Armada XP GP is configured as RGMII-ID, and needs the PCS bit to be
       set.
     * Armada 370 Mirabox is configured as RGMII-ID, and needs the PCS bit
       to be cleared.
    
    And at the moment, we don't know how to make the distinction between
    those two cases. One hint is that the Armada XP GP appears in fact to
    be using a QSGMII connection with the PHY (Quad-SGMII), but
    configuring it as SGMII doesn't work, while RGMII-ID works. This needs
    more investigation, but in the mean time, let's unbreak the network
    for all those users.
    
    Signed-off-by: default avatarThomas Petazzoni <thomas.petazzoni@free-electrons.com>
    Reported-by: default avatarArnaud Ebalard <arno@natisbad.org>
    Reported-by: default avatarAlexander Reuter <Alexander.Reuter@gmx.net>
    Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=73401
    
    
    Cc: stable@vger.kernel.org
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    cc6ca302