cvs commit: www/en/projects/busdma index.sgml

[Scott Long]

Joel Dahl wrote:

> joel        2006-09-01 09:17:38 UTC
> 
>   FreeBSD doc repository
> 
>   Modified files:
>     en/projects/busdma   index.sgml 
>   Log:
>   -  Add a bunch of missing USB network drivers: aue(4), axe(4), cdce(4),
>      cue(4), kue(4), rue(4) and udav(4).  Mark everything as unknown for now.
>   -  Fix minor nits.
>   
>   Revision  Changes    Path
>   1.147     +87 -10    www/en/projects/busdma/index.sgml

The DMA capability of a USB peripheral is a function of the USB stack 
and controller, not the peripheral driver.  Unlike a PCI card, a USB
periph does not have access to host memory.  All of the real magic seems
to happen in places like usbd_setup_xfer(), which again is a function of
the stack, not the periph driver.  These drivers don't belong on this
list at all, and I'd argue that no USB periph drivers do.

Scott