On 9/12/2019 9:28 AM, Alexandru Ardelean wrote: > The `phy_tunable_id` has been named `ETHTOOL_PHY_EDPD` since it looks like > this feature is common across other PHYs (like EEE), and defining > `ETHTOOL_PHY_ENERGY_DETECT_POWER_DOWN` seems too long. > > The way EDPD works, is that the RX block is put to a lower power mode, > except for link-pulse detection circuits. The TX block is also put to low > power mode, but the PHY wakes-up periodically to send link pulses, to avoid > lock-ups in case the other side is also in EDPD mode. > > Currently, there are 2 PHY drivers that look like they could use this new > PHY tunable feature: the `adin` && `micrel` PHYs. > > The ADIN's datasheet mentions that TX pulses are at intervals of 1 second > default each, and they can be disabled. For the Micrel KSZ9031 PHY, the > datasheet does not mention whether they can be disabled, but mentions that > they can modified. > > The way this change is structured, is similar to the PHY tunable downshift > control: > * a `ETHTOOL_PHY_EDPD_DFLT_TX_MSECS` value is exposed to cover a default > TX interval; some PHYs could specify a certain value that makes sense > * `ETHTOOL_PHY_EDPD_NO_TX` would disable TX when EDPD is enabled > * `ETHTOOL_PHY_EDPD_DISABLE` will disable EDPD > > As noted by the `ETHTOOL_PHY_EDPD_DFLT_TX_MSECS` the interval unit is 1 > millisecond, which should cover a reasonable range of intervals: > - from 1 millisecond, which does not sound like much of a power-saver > - to ~65 seconds which is quite a lot to wait for a link to come up when > plugging a cable > > Signed-off-by: Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx> Reviewed-by: Florian Fainelli <f.fainelli@xxxxxxxxx> -- Florian
