[PATCH 05/04] *** NOT FOR RELEASE *** HACK *** Work around MII clock issue ***

Wolfgang Denk wd at denx.de
Mon Jun 8 06:34:06 EST 2009


Dear John,

in message <4b73d43f0906061708o763409d0u10a344dfc30e32c1 at mail.gmail.com> you wrote:
>
> > The big question seems to be what the RefMan means when talking about
> > the "system clock frequency". Obiously it is NOT  the  CPU  clock  as
...
> > But which one is it?
> 
> My best guess is still that it is ips clock.  I think I stated in a previous
> email ipb, but I meant ips.  5200 has ibp and 5121 has ips.  Have you looked
> at he MII clock on a scope to see how the calculated values compare to
> actual?

Yes, it seems very much as if you were right again.

When using ips/ibp everything makes sense, and works.

Hm... so that means on MPC512x we should use mpc512x_find_ips_freq(),
while on MPC5200 we should use  mpc52xx_find_ipb_freq()  -  but  hey,
apart from the name these two functions are identical.

Grant - how would you like to see this handled? Should we merge these
two code-wise identical functions into one?  What should be the name,
and in which file should we put it?

[We need this clock thing for "drivers/net/fs_enet/mii-fec.c"...]

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
"Don't think; let the machine do it for you!"        - E. C. Berkeley


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