Re: Question about network cards for Linux Alpha.

Paul Gortmaker (gpg109@rsphy1.anu.edu.au)
Wed, 18 Sep 1996 14:55:20 +1000 (EST)


[CC'd to linux-alpha, as someone there may have tried this card already]

> Hewlett Packard Desk Direct 10/100VG PCI LAN Adapter
>
> HP Model# J2585A
>
> I saw your name in the faq for network drivers. I wondered if the
> above card will work, and if not anything special I need to know to port
> the intel linux version to the alpha?
>

I don't know if anyone has tried it yet. I had a quick glance at the
driver, and most of it appears "alpha" clean, but there are a couple
of spots where it needs some minor changes, for example:

hp100_andw( ~HP100_LINK_CMD, LAN_CFG_VG );
- time = jiffies + 10;
+ time = jiffies + 10*HZ/100;
while ( time > jiffies )

In general there are a few main things to watch out for:

1) Jiffies values that are used as timeouts need to be mult by HZ/100
so that the timeout remains the same for i386 and alpha

2) You can't do a direct dereference of a pointer into i/o space,
instead use readb, readw, readl and the writeb/w/l equivalents.

3) You can't memcpy() from i/o memory space (actually same problem as
above) -- instead use memcpy_fromio() and memcpy_toio()

4) SLOW_DOWN_IO apparently doesn't slow down i/o -- use udelay() instead
if you need it for slow things like EEPROM reads.

Paul.

> Thanks,
>
> Alan