[U-Boot] [RFC] CONFIG_RESET_PHY_R feature is broken

[Ilya Yanok <yanok@emcraft.com>]

Hello Ben, Everybody,

some boards used to have their PHY quirks in board-specific reset_phy() 
function. This used to work because of reset_phy() being called later 
than Ethernet drivers initialization during startup.
But nowadays some drivers (in particular I faced this problem using 
mpc5xxx_fec driver) use 'on demand' PHY initialization, and 
board-specific quirks don't have effect any more... Actually, 
CONFIG_RESET_PHY_R is broken even without 'on demand' PHY 
initialization: at least mpc5xxx_fec driver can decide to reinit PHY 
during normal operation and board-specific reset_phy() function won't be 
called in this case too... Another design flaw of the CONFIG_RESET_PHY_R 
feature is that boards with more than one Ethernet controller are pretty 
common today and usually we want to initialize only the PHY connected to 
the controller we are trying to use at the moment and there is no way to 
tell the reset_phy() function which PHY we want to reset...

Ben, do you have any ideas how we could fix this?

I believe on of possible solutions here would be to introduce generic 
PHY layer in U-Boot but unfortunately this would be too much efforts for 
us in this project... Maybe somebody is aware of such work being done so 
we can join?

Regards, Ilya.