Subject: Re: commproc.c

From: Dan Malek <[email-masked]>
Date: Thu, 02 Mar 2000 11:22:23 -0500

Steve Calfee wrote:

> I have been working on doing a 823 USB driver.

I find it interesting there is a sudden interest in the 8xx USB
interface.......

I recently hired someone to do this work for a customer.  We have
slave working fine, and host mostly works (some hubs give us fits).
The goal is an isochronous connection for some device to stream
data over a variety of communication links (it's an 850).

We still have a little distance to cover.  If someone needs this
for a product and wants to invest in speeding up the develpment,
let me know.  Once it is more useful I suppose it will find its
way into the source tree.

> m8xx_cpm_dpalloc(uint size)

> This is a primitive routine to allocate CPM memory. It allocates size bytes
> of CPM memory. Even a good citizen that lives by the CPM imposed
> constraints of alignment

I had some pretty bad hacks for ATM interfaces due to its alignment
restrictions, and have since added a second parameter to define alignment.
I have played with masks and byte counts, one will win.  This will
be in an upcoming patch.

> .... We also need a m8xx_cpm_free() function to give back CPM
> memory when we are done.

For lack of a better thought, I have resurrected the old *NIX resource
map allocator.  Seems to work.

> .... I agree that it is a rare use,

It's not only rare, but I don't see any use for it.

> .... but if I want to
> backtrace the interrupted stack from my interrupt routine for profiling...

You have to explain this one to me.  I don't understand how passing
the register set pointer has any effect on this operation.

Show me you need it and we can add it as a parameter.  There aren't
that many places to change the code.  I just didn't need it, and due
to your rant about interrupt overhead why add something not needed?

	-- Dan

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