cvs commit: src/sys/pci if_dc.c

[Mike Silbersack]

On Tue, 8 Mar 2005, Scott Long wrote:

>  The DC driver asks for an alignment of PAGE_SIZE for data buffers, but also
>  asks that each buffer be (2048 * 256) bytes long.  I suspect that alignment
>  isn't a real requirement since busdma only recently started honoring it.  The
>  size is also bogus.  Fix both of these and stop busdma from trying to
>  exhaust the system memory pool with bounce pages.

The requirement as it was originally stated is that they may need to be 
longword aligned for certain cards.  We handle that in dc_encap already, 
but I hadn't considered the possible problem with using bounce pages.

I'll take a look and see if we can determine the alignment requirement 
before we call bus_dma_tag_create.

Are there any busdma statistics sysctls that would let us notice that it's 
being asked to do things like this on a running system?  If not, could you 
add some?

Mike "Silby" Silbersack