• Stas Sergeev's avatar
    of_mdio: add new DT property 'managed' to specify the PHY management type · 4cba5c21
    Stas Sergeev authored
    Currently the PHY management type is selected by the MAC driver arbitrary.
    The decision is based on the presence of the "fixed-link" node and on a
    will of the driver's authors.
    This caused a regression recently, when mvneta driver suddenly started
    to use the in-band status for auto-negotiation on fixed links.
    It appears the auto-negotiation may not work when expected by the MAC driver.
    Sebastien Rannou explains:
    << Yes, I confirm that my HW does not generate an in-band status. AFAIK, it's
    a PHY that aggregates 4xSGMIIs to 1xQSGMII ; the MAC side of the PHY (with
    inband status) is connected to the switch through QSGMII, and in this context
    we are on the media side of the PHY. >>
    https://lkml.org/lkml/2015/7/10/206
    
    This patch introduces the new string property 'managed' that allows
    the user to set the management type explicitly.
    The supported values are:
    "auto" - default. Uses either MDIO or nothing, depending on the presence
    of the fixed-link node
    "in-band-status" - use in-band status
    Signed-off-by: default avatarStas Sergeev <stsp@users.sourceforge.net>
    
    CC: Rob Herring <robh+dt@kernel.org>
    CC: Pawel Moll <pawel.moll@arm.com>
    CC: Mark Rutland <mark.rutland@arm.com>
    CC: Ian Campbell <ijc+devicetree@hellion.org.uk>
    CC: Kumar Gala <galak@codeaurora.org>
    CC: Florian Fainelli <f.fainelli@gmail.com>
    CC: Grant Likely <grant.likely@linaro.org>
    CC: devicetree@vger.kernel.org
    CC: linux-kernel@vger.kernel.org
    CC: netdev@vger.kernel.org
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    4cba5c21
of_mdio.c 8.57 KB