[RFC] Patch to Abstract Ethernet PHY support (using driver model)

[Eugene Surovegin]

On Thu, Dec 23, 2004 at 03:00:13PM -0600, Andy Fleming wrote:
> 
> >Adds a Phy Abstraction Layer which allows ethernet controllers to 
> >manage their PHYs without knowing the details of how the particular 
> >PHY device operates.  This code steals heavily from BenH's  sungem 
> >driver, and got some stuff out of Jason McMullan's patch.

Some random notes from quick look at the code:

1) IMO if we can extract some info from the PHY using _standard_ 
registers we should use them, even if the PHY provides some custom 
ones. 

I suspect that _all_ XXX_read_status functions for different PHYs in 
your patch can be easily handled by generic IEEE 802.3 compliant code 
(you need to update genphy_read_status to properly handle GigE of 
course).

2) genphy can be changed to handle GigE speeds as well.

3) I think it's better for the genphy case to _detect_ PHY features 
instead of hard coding PHY_BASIC_FEATURES. In this case you can easily 
handle 10/100 and 10/100/1000 PHYs by genphy code.

4) Pause negotiation/advertising is completely missing.

5) PHY interrupt sharing looks broken. Although you request_irq using 
SA_SHIRQ flag, in the handler itself you don't detect whether this 
interrupt is for this PHY or not, and return IRQ_HANDLED. This will 
result in first registered PHY hijacking IRQs from other PHYs (or 
devices) sharing the same IRQ line.

--
Eugene