1. 07 Oct, 2021 1 commit
    • Ido Schimmel's avatar
      ethtool: Add ability to control transceiver modules' power mode · 353407d9
      Ido Schimmel authored
      Add a pair of new ethtool messages, 'ETHTOOL_MSG_MODULE_SET' and
      'ETHTOOL_MSG_MODULE_GET', that can be used to control transceiver
      modules parameters and retrieve their status.
      
      The first parameter to control is the power mode of the module. It is
      only relevant for paged memory modules, as flat memory modules always
      operate in low power mode.
      
      When a paged memory module is in low power mode, its power consumption
      is reduced to the minimum, the management interface towards the host is
      available and the data path is deactivated.
      
      User space can choose to put modules that are not currently in use in
      low power mode and transition them to high power mode before putting the
      associated ports administratively up. This is useful for user space that
      favors reduced power consumption and lower temperatures over reduced
      link up times. In QSFP-DD modules the transition from low power mode to
      high power mode can take a few seconds and this transition is only
      expected to get longer with future / more complex modules.
      
      User space can control the power mode of the module via the power mode
      policy attribute ('ETHTOOL_A_MODULE_POWER_MODE_POLICY'). Possible
      values:
      
      * high: Module is always in high power mode.
      
      * auto: Module is transitioned by the host to high power mode when the
        first port using it is put administratively up and to low power mode
        when the last port using it is put administratively down.
      
      The operational power mode of the module is available to user space via
      the 'ETHTOOL_A_MODULE_POWER_MODE' attribute. The attribute is not
      reported to user space when a module is not plugged-in.
      
      The user API is designed to be generic enough so that it could be used
      for modules with different memory maps (e.g., SFF-8636, CMIS).
      
      The only implementation of the device driver API in this series is for a
      MAC driver (mlxsw) where the module is controlled by the device's
      firmware, but it is designed to be generic enough so that it could also
      be used by implementations where the module is controlled by the CPU.
      
      CMIS testing
      ============
      
       # ethtool -m swp11
       Identifier                                : 0x18 (QSFP-DD Double Density 8X Pluggable Transceiver (INF-8628))
       ...
       Module State                              : 0x03 (ModuleReady)
       LowPwrAllowRequestHW                      : Off
       LowPwrRequestSW                           : Off
      
      The module is not in low power mode, as it is not forced by hardware
      (LowPwrAllowRequestHW is off) or by software (LowPwrRequestSW is off).
      
      The power mode can be queried from the kernel. In case
      LowPwrAllowRequestHW was on, the kernel would need to take into account
      the state of the LowPwrRequestHW signal, which is not visible to user
      space.
      
       $ ethtool --show-module swp11
       Module parameters for swp11:
       power-mode-policy high
       power-mode high
      
      Change the power mode policy to 'auto':
      
       # ethtool --set-module swp11 power-mode-policy auto
      
      Query the power mode again:
      
       $ ethtool --show-module swp11
       Module parameters for swp11:
       power-mode-policy auto
       power-mode low
      
      Verify with the data read from the EEPROM:
      
       # ethtool -m swp11
       Identifier                                : 0x18 (QSFP-DD Double Density 8X Pluggable Transceiver (INF-8628))
       ...
       Module State                              : 0x01 (ModuleLowPwr)
       LowPwrAllowRequestHW                      : Off
       LowPwrRequestSW                           : On
      
      Put the associated port administratively up which will instruct the host
      to transition the module to high power mode:
      
       # ip link set dev swp11 up
      
      Query the power mode again:
      
       $ ethtool --show-module swp11
       Module parameters for swp11:
       power-mode-policy auto
       power-mode high
      
      Verify with the data read from the EEPROM:
      
       # ethtool -m swp11
       Identifier                                : 0x18 (QSFP-DD Double Density 8X Pluggable Transceiver (INF-8628))
       ...
       Module State                              : 0x03 (ModuleReady)
       LowPwrAllowRequestHW                      : Off
       LowPwrRequestSW                           : Off
      
      Put the associated port administratively down which will instruct the
      host to transition the module to low power mode:
      
       # ip link set dev swp11 down
      
      Query the power mode again:
      
       $ ethtool --show-module swp11
       Module parameters for swp11:
       power-mode-policy auto
       power-mode low
      
      Verify with the data read from the EEPROM:
      
       # ethtool -m swp11
       Identifier                                : 0x18 (QSFP-DD Double Density 8X Pluggable Transceiver (INF-8628))
       ...
       Module State                              : 0x01 (ModuleLowPwr)
       LowPwrAllowRequestHW                      : Off
       LowPwrRequestSW                           : On
      
      SFF-8636 testing
      ================
      
       # ethtool -m swp13
       Identifier                                : 0x11 (QSFP28)
       ...
       Extended identifier description           : 5.0W max. Power consumption,  High Power Class (> 3.5 W) enabled
       Power set                                 : Off
       Power override                            : On
       ...
       Transmit avg optical power (Channel 1)    : 0.7733 mW / -1.12 dBm
       Transmit avg optical power (Channel 2)    : 0.7649 mW / -1.16 dBm
       Transmit avg optical power (Channel 3)    : 0.7790 mW / -1.08 dBm
       Transmit avg optical power (Channel 4)    : 0.7837 mW / -1.06 dBm
       Rcvr signal avg optical power(Channel 1)  : 0.9302 mW / -0.31 dBm
       Rcvr signal avg optical power(Channel 2)  : 0.9079 mW / -0.42 dBm
       Rcvr signal avg optical power(Channel 3)  : 0.8993 mW / -0.46 dBm
       Rcvr signal avg optical power(Channel 4)  : 0.8778 mW / -0.57 dBm
      
      The module is not in low power mode, as it is not forced by hardware
      (Power override is on) or by software (Power set is off).
      
      The power mode can be queried from the kernel. In case Power override
      was off, the kernel would need to take into account the state of the
      LPMode signal, which is not visible to user space.
      
       $ ethtool --show-module swp13
       Module parameters for swp13:
       power-mode-policy high
       power-mode high
      
      Change the power mode policy to 'auto':
      
       # ethtool --set-module swp13 power-mode-policy auto
      
      Query the power mode again:
      
       $ ethtool --show-module swp13
       Module parameters for swp13:
       power-mode-policy auto
       power-mode low
      
      Verify with the data read from the EEPROM:
      
       # ethtool -m swp13
       Identifier                                : 0x11 (QSFP28)
       Extended identifier description           : 5.0W max. Power consumption,  High Power Class (> 3.5 W) not enabled
       Power set                                 : On
       Power override                            : On
       ...
       Transmit avg optical power (Channel 1)    : 0.0000 mW / -inf dBm
       Transmit avg optical power (Channel 2)    : 0.0000 mW / -inf dBm
       Transmit avg optical power (Channel 3)    : 0.0000 mW / -inf dBm
       Transmit avg optical power (Channel 4)    : 0.0000 mW / -inf dBm
       Rcvr signal avg optical power(Channel 1)  : 0.0000 mW / -inf dBm
       Rcvr signal avg optical power(Channel 2)  : 0.0000 mW / -inf dBm
       Rcvr signal avg optical power(Channel 3)  : 0.0000 mW / -inf dBm
       Rcvr signal avg optical power(Channel 4)  : 0.0000 mW / -inf dBm
      
      Put the associated port administratively up which will instruct the host
      to transition the module to high power mode:
      
       # ip link set dev swp13 up
      
      Query the power mode again:
      
       $ ethtool --show-module swp13
       Module parameters for swp13:
       power-mode-policy auto
       power-mode high
      
      Verify with the data read from the EEPROM:
      
       # ethtool -m swp13
       Identifier                                : 0x11 (QSFP28)
       ...
       Extended identifier description           : 5.0W max. Power consumption,  High Power Class (> 3.5 W) enabled
       Power set                                 : Off
       Power override                            : On
       ...
       Transmit avg optical power (Channel 1)    : 0.7934 mW / -1.01 dBm
       Transmit avg optical power (Channel 2)    : 0.7859 mW / -1.05 dBm
       Transmit avg optical power (Channel 3)    : 0.7885 mW / -1.03 dBm
       Transmit avg optical power (Channel 4)    : 0.7985 mW / -0.98 dBm
       Rcvr signal avg optical power(Channel 1)  : 0.9325 mW / -0.30 dBm
       Rcvr signal avg optical power(Channel 2)  : 0.9034 mW / -0.44 dBm
       Rcvr signal avg optical power(Channel 3)  : 0.9086 mW / -0.42 dBm
       Rcvr signal avg optical power(Channel 4)  : 0.8885 mW / -0.51 dBm
      
      Put the associated port administratively down which will instruct the
      host to transition the module to low power mode:
      
       # ip link set dev swp13 down
      
      Query the power mode again:
      
       $ ethtool --show-module swp13
       Module parameters for swp13:
       power-mode-policy auto
       power-mode low
      
      Verify with the data read from the EEPROM:
      
       # ethtool -m swp13
       Identifier                                : 0x11 (QSFP28)
       ...
       Extended identifier description           : 5.0W max. Power consumption,  High Power Class (> 3.5 W) not enabled
       Power set                                 : On
       Power override                            : On
       ...
       Transmit avg optical power (Channel 1)    : 0.0000 mW / -inf dBm
       Transmit avg optical power (Channel 2)    : 0.0000 mW / -inf dBm
       Transmit avg optical power (Channel 3)    : 0.0000 mW / -inf dBm
       Transmit avg optical power (Channel 4)    : 0.0000 mW / -inf dBm
       Rcvr signal avg optical power(Channel 1)  : 0.0000 mW / -inf dBm
       Rcvr signal avg optical power(Channel 2)  : 0.0000 mW / -inf dBm
       Rcvr signal avg optical power(Channel 3)  : 0.0000 mW / -inf dBm
       Rcvr signal avg optical power(Channel 4)  : 0.0000 mW / -inf dBm
      Signed-off-by: default avatarIdo Schimmel <idosch@nvidia.com>
      Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
      353407d9
  2. 06 Oct, 2021 10 commits
  3. 05 Oct, 2021 29 commits