HT initialization

Stephen.Kimball at Stephen.Kimball at
Mon Jan 24 11:34:00 CET 2005

Thanks.  I suspected the HT frequency change needed the soft_reset.
I don't want to try LD_STOP so I'll need to get warm or soft reset to work.


-----Original Message-----
From: Stefan Reinauer [mailto:stepan at] 
Sent: Monday, January 24, 2005 12:57 PM
To: Kimball, Stephen
Cc: linuxbios at
Subject: Re: HT initialization

* Stephen.Kimball at <Stephen.Kimball at> [050124 17:38]:
> I'm trying to port LinuxBIOS to a Opteron board with a CK804.
IIRC Yinghai Lu did some CK804 work as well.

> In auto.c I notice that most boards call ht_setup_chain() and use the
> return code to see if a reset is needed.  Since I can't seem to get
> soft_reset() to work with the CK804, can some on tell me why HT
> initialization needs a reset?  Thanks.

The hypertransport links only change their speed after an LDTSTOP_L
signal or soft reset. Otherwise the values written to the registers are
not in charge.

Since LDTSTOP is more complicated, though it has less impact on the
system, LinuxBIOS uses soft reset all over the place. 

You need to check where your southbridge is and adapt the soft_reset()
function in auto.c (bus,dev,fn number etc)


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