Re: [PATCH net-next 0/2] net: phy: improve PM handling of PHY/MDIO

[Andrew Lunn <andrew@lunn.ch>]

On Sat, Jun 02, 2018 at 10:33:36PM +0200, Heiner Kallweit wrote:
> Current implementation of MDIO bus PM ops doesn't actually implement
> bus-specific PM ops but just calls PM ops defined on a device level
> what doesn't seem to be fully in line with the core PM model.
> 
> When looking e.g. at __device_suspend() the PM core looks for PM ops
> of a device in a specific order:
> 1. device PM domain
> 2. device type
> 3. device class
> 4. device bus
> 
> I think it has good reason that there's no PM ops on device level.
> The situation can be improved by modeling PHY's as device type of
> a MDIO device. If for some other type of MDIO device PM ops are
> needed, it could be modeled as struct device_type as well.

Hi Heiner

I tested that the files in /sys/class/bus/mdio/devices/* are still
there. And also not there for MDIO devices which are not PHYs,
e.g. Ethernet switches.

I don't have any boards which do PM. So i cannot test suspend/resume.

I also took a look at drivers/net/dsa/qca8k.c. This is an MDIO switch
which has PM operations. I don't think this change will break it.

I would prefer a bit more testing, but i guess that is what -rc
kernels are for.

Tested-by: Andrew Lunn <andrew@lunn.ch>

    Andrew