On 11.02.2021 13:17, Pavel Machek wrote: > On Thu 2021-01-14 12:05:21, Heiner Kallweit wrote: >> On 14.01.2021 11:41, claudiu.bez...@microchip.com wrote: >>> >>> >>> On 14.01.2021 12:25, Russell King - ARM Linux admin wrote: >>>> >>>> As I've said, if phylib/PHY driver is not restoring the state of the >>>> PHY on resume from suspend-to-ram, then that's an issue with phylib >>>> and/or the phy driver. >>> >>> In the patch I proposed in this thread the restoring is done in PHY driver. >>> Do you think I should continue the investigation and check if something >>> should be done from the phylib itself? >>> >> It was the right move to approach the PM maintainers to clarify whether >> the resume PM callback has to assume that power had been cut off and >> it has to completely reconfigure the device. If they confirm this >> understanding, then: > > Power to some devices can be cut during s2ram, yes. > Thanks for the confirmation.
>> - the general question remains why there's separate resume and restore >> callbacks, and what restore is supposed to do that resume doesn't >> have to do > > You'll often have same implementation, yes. > If resume and restore both have to assume that power was cut off, then they have to fully re-initialize the device. Therefore it's still not clear to me when you would have differing implementations for both callbacks. >> - it should be sufficient to use mdio_bus_phy_restore also as resume >> callback (instead of changing each and every PHY driver's resume), >> because we can expect that somebody cutting off power to the PHY >> properly suspends the MDIO bus before > > If restore works with power cut and power not cut then yes, you should > get away with that. > > Best regards, > Pavel > Heiner
