Subject: Re: bus_dma, the next chapter...
To: Jason R Thorpe <thorpej@zembu.com>
From: Matthew Jacob <mjacob@feral.com>
List: tech-kern
Date: 02/27/2001 16:00:22
On Tue, 27 Feb 2001, Jason R Thorpe wrote:

> On Tue, Feb 27, 2001 at 03:11:18PM -0800, Matthew Jacob wrote:
> 
>  > so in my quest to DTRT with BusDma, I changed the PCI code to
>  > use bus_dmamap_load_raw as the SBus code was changed to do- after
>  > all- if it is right for one, it must be right for another.
> 
> You shouldn't be using bus_dmamap_load_raw() for any buffer which
> is mapped into an address space.
> 
> 

Architectural consistency? The man page says:

     bus_dmamap_load_raw(tag, dmam, segs, nsegs, size, flags)
              This is a variation of bus_dmamap_load() which maps buffers al-
              located by bus_dmamem_alloc() (see below).  The segs argument is
              an array of bus_dma_segment_t's filled in by bus_dmamem_alloc().
              The nsegs argument is the number of segments in the array.  The
              size argument is the size of the DMA transfer.


It says absolutely nothing about mapping in or out of any address space.

So- which is it? Your comment (author's intention) or the man page?


-matt