Subject: Re: Valid use of bus_dma(9)?
To: None <tech-kern@NetBSD.org>
From: David Young <firstname.lastname@example.org>
Date: 07/23/2004 15:38:09
On Fri, Jul 23, 2004 at 05:19:23PM +0200, Manuel Bouyer wrote:
> bus_dmamem_alloc(9) says:
> The mapping of this memory is machine-dependent (or "opaque");
> machine-independent code is not to assume that the addresses
> returned are valid in kernel virtual address space, or that the
> addresses returned are system physical addresses. The address
> To me, this means that we can't make any assumptions about the values returned
> by bus_dmamem_alloc(), and especially it's wrong to assume we can do
> memory-related operations on ds_addr/ds_len.
Network drivers don't copy ds_addr into transmit/receive descriptors?
How does this work if they are not "system physical addresses" ?
David Young OJC Technologies
email@example.com Urbana, IL * (217) 278-3933