Subject: Re: FreeBSD Bus DMA
To: Jonathan Stone <>
From: Jason Thorpe <>
List: tech-kern
Date: 06/11/1998 16:16:38
On Thu, 11 Jun 1998 16:11:42 -0700 
 Jonathan Stone <jonathan@DSG.Stanford.EDU> wrote:

 > one of the things Justin added was a driver-specific filter function.
 > Justin says that's a better way to detect mappings that oculd tickle
 > driver bugs.  VLB buslogic boards were given as a specific example; it
 > sounds plausible to me.  (I'd assume that if NetBSD added this, the
 > filter argument would be NULL in almost all cases).

The only VLB BusLogic bug I'm aware of is the inability to properly
do DMA using 32-bit addresses.  Our driver currently handles that case.

 > Does that count as concrete justification -- at least if the
 > filter-function works without switching to a callback-based model?

Jason R. Thorpe                             
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