Re: [PATCH 2/2] net: phy: realtek: Add optional external PHY clock

[Florian Fainelli]

On 6/1/23 12:37, Andrew Lunn wrote:
> > I'm not sure about this. Isn't the clock still necessary when suspended for
> > things like wake on lan ?
>
> Yes, but the PHY should know if its a WoL source, and not disable its
> own clock. There is some support for this in phylib, and Florian has
> also reworked it recently for Broadcom PHYs.

If you want to have the PHY driver have a chance to disable the clock if 
Wake-on-LAN is disabled and therefore conserve power, you should set 
PHY_ALWAYS_CALL_SUSPEND in the phy_driver::flags and in the 
suspend/resume functions do something like:

suspend:
	/* last step after all registers are accessed */
	if (!phydev->wol_enabled)
		clk_disable_unprepare()
resume:
	/* first step before registers are accessed */
	if (!phydev->wol_enabled)
		clk_prepare_enable()

The flag is necessary to ensure that the PHY driver's suspend function 
will be called. The resume will be called regardless of Wake-on-LAN 
being enabled or not.
--
Florian