• Niklas Cassel's avatar
    bindings: net: stmmac: correctify note about LPI interrupt · 3ec26c79
    Niklas Cassel authored
    There are two different combined signal for various interrupt events:
    In EQOS-CORE and EQOS-MTL configurations, mci_intr_o is the interrupt
    signal.
    In EQOS-DMA, EQOS-AHB and EQOS-AXI configurations, these interrupt events
    are combined with the events in the DMA on the sbd_intr_o signal.
    
    Depending on configuration, the device tree irq "macirq" will refer to
    either mci_intr_o or sbd_intr_o.
    
    The databook states:
    "The MAC generates the LPI interrupt when the Tx or Rx side enters or exits
    the LPI state. The interrupt mci_intr_o (sbd_intr_o in certain
    configurations) is asserted when the LPI interrupt status is set.
    
    When the MAC exits the Rx LPI state, then in addition to the mci_intr_o
    (sbd_intr_o in certain configurations), the sideband signal lpi_intr_o is
    asserted.
    
    If you do not want to gate-off the application clock during the Rx LPI
    state, you can leave the lpi_intr_o signal unconnected and use the
    mci_intr_o (sbd_intr_o in certain configurations) signal to detect Rx LPI
    exit."
    
    Since the "macirq" is always raised when Tx or Rx enters/exits the LPI
    state, "eth_lpi" must therefore refer to lpi_intr_o, which is only raised
    when Rx exits the LPI state. Update the DT binding description to reflect
    reality.
    Signed-off-by: default avatarNiklas Cassel <niklas.cassel@axis.com>
    Acked-by: default avatarAlexandre TORGUE <alexandre.torgue@st.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    3ec26c79
stmmac.txt 7.28 KB