Re: [iPAQ] Ipaq Pcmcia 2fast4you ?

On Tue, 17 Apr 2001 tytso@thunk.org wrote:

> So was this a bit of lore that everyone else knew? Was I just
> unlucky? Also, does this work by actually slowing down the CPU? If
> so, it seems kinda a lose that I'm going to have to slow down the
> (already not-terribly-blazing-fast) ARM processor just to keep the
> PCMCIA card happy.

Someone needs to review the PCMCIA timing initialization in
drivers/pcmcia/sa1100-generic.c.

> Also, I tried looking in the stock Linux 2.4.3 kernel sources and
> couldn't find where /proc/scale is getting set up. I assume this is
> an arm/iPAQ kernel special?

Yep. It is a special module that allows you to change the processor's speed
on the fly. With the SA1110 this isn't a futile thing since most timings
(RAM, PCMCIA, LCD, etc) are derived from the core processor clock. Since
the /proc/scale interface actually take care of readjusting the dram timing,
it does not modify the PCMCIA one.

Therefore it seems that the PCMCIA timing isn't correctly set in the first
place.

Nicolas
Received on Tue Apr 17 13:06:31 2001