Hi Heiner, On 08.01.2021 18:31, Heiner Kallweit wrote: > EXTERNAL EMAIL: Do not click links or open attachments unless you know the > content is safe > > On 08.01.2021 16:45, Claudiu Beznea wrote: >> KSZ9131 is used in setups with SAMA7G5. SAMA7G5 supports a special >> power saving mode (backup mode) that cuts the power for almost all >> parts of the SoC. The rail powering the ethernet PHY is also cut off. >> When resuming, in case the PHY has been configured on probe with >> slew rate or DLL settings these needs to be restored thus call >> driver's config_init() on resume. >> > When would the SoC enter this backup mode?
It could enter in this mode based on request for standby or suspend-to-mem: echo mem > /sys/power/state echo standby > /sys/power/state What I didn't mentioned previously is that the RAM remains in self-refresh while the rest of the SoC is powered down. > And would it suspend the > MDIO bus before cutting power to the PHY? SAMA7G5 embeds Cadence macb driver which has a integrated MDIO bus. Inside macb driver the bus is registered with of_mdiobus_register() or mdiobus_register() based on the PHY devices present in DT or not. On macb suspend()/resume() functions there are calls to phylink_stop()/phylink_start() before cutting/after enabling the power to the PHY. > I'm asking because in mdio_bus_phy_restore() we call phy_init_hw() > already (that calls the driver's config_init). As far as I can see from documentation the .restore API of dev_pm_ops is hibernation specific (please correct me if I'm wrong). On transitions to backup mode the suspend()/resume() PM APIs are called on the drivers. Thank you, Claudiu Beznea > >> Signed-off-by: Claudiu Beznea <claudiu.bez...@microchip.com> >> --- >> drivers/net/phy/micrel.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c >> index 3fe552675dd2..52d3a0480158 100644 >> --- a/drivers/net/phy/micrel.c >> +++ b/drivers/net/phy/micrel.c >> @@ -1077,7 +1077,7 @@ static int kszphy_resume(struct phy_device *phydev) >> */ >> usleep_range(1000, 2000); >> >> - ret = kszphy_config_reset(phydev); >> + ret = phydev->drv->config_init(phydev); >> if (ret) >> return ret; >> >> >
