Subject: Re: bus_dmamap_sync() in ti(4) or the lack thereof
To: Tobias Nygren <tnn+nbsd@nygren.pp.se>
From: Matt Thomas <matt@3am-software.com>
List: tech-kern
Date: 02/27/2007 13:55:11
Tobias Nygren wrote:
> Folks,
> 
> ti(4) doesn't work right on sparc64. With DIAGNOSTIC i get tons
> of "iommu_dvmamap_load: map still in use".
> 
> I took a glance at the ti(4) code and noticed the absence of any
> preread/postread dma syncs, despite the fact that the driver relies
> heavily on reuse of dma maps. This can't be right, can it?
> 
> The fact that the driver appears to reload maps without unloading
> them first might be caused by something else, though.
> 
> Thoughts?

It depends on whether it was running on a system with cache coherence or not.

ti works fine on alpha, for instance, since it's cache coherent.
-- 
Matt Thomas
Cupertino, CA