Heiner Kallweit says:
====================
net: make PHY PM ops a no-op if MAC driver manages PHY PM
Resume callback of the PHY driver is called after the one for the MAC
driver. The PHY driver resume callback calls phy_init_hw(), and this is
potentially problematic if the MAC driver calls phy_start() in its resume
callback. One issue was reported with the fec driver and a KSZ8081 PHY
which seems to become unstable if a soft reset is triggered during aneg.
The new flag allows MAC drivers to indicate that they take care of
suspending/resuming the PHY. Then the MAC PM callbacks can handle
any dependency between MAC and PHY PM.
====================
Link: https://lore.kernel.org/r/9e695411-ab1d-34fe-8b90-3e8192ab84f6@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>