On Fri, 14 January 2005 07:25:18 -0800, Eugene Surovegin wrote:

On Fri, Jan 14, 2005 at 03:55:18PM +0100, J?rn Engel wrote:

quoted

Wrt. the proposed PHY lib, I agree.  Didn't even bother to look at the
code, it's mere size said enough.

But an abstraction different from drivers/net/mii.c is needed to
handle the 5325 chip.  Or, you could have the special cases all over
in your code, but that's a) ugly and b) more code.  I used to have
such a mess and after doing the proper abstraction, it line count went
down.

Well, I still fail to see what is so _special_ about this chip that it 
needs "proper abstraction". Could you elaborate, please?

The way I handled this in my drivers was clean and simple - 
"there-is-no-PHY". And this wasn't in any case chip-specific and was 
set up through OCP in board support code. So I'm kinda puzzled what 
"ugliness and more code" you are talking about.

We can also make a fake PHY which will always indicate link, will have 
fixed speed/duplex capabilities and will not support autoneg. If you 
think this is more elegant, OK, I might even agree with you :).

Exactly.  You need link status, speed and duplex status at the least.
Put query functions for those three into a struct phy_ops or whatever
it may be called and you're done.

Depending on your hardware, you may also need something more
complicated for various fixups, etc.  But it's mostly those three
functions.

Please, note that wrt current discussion we are interested only in CPU 
port, not other 5 ports which aren't connected to the CPU at all. This 
is completely different stuff and yes, if we want to expose them in 
some way we need another abstraction. But abstraction of switch chips 
is a big and complex thing - they are very different, and frankly this 
one you mentioned is quite "feature-challenged" and will not make 
a good "model" chip IMHO :).

Well, it's one of the few I've had to worry about so far.  I'm a big
non-believer in abstractions I just don't need yet.  The one outlined
above I already needed.

Jörn

-- 
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