Re: port-amd64/42980: satalink DMA fails under amd64

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Thu, Mar 18, 2010 at 02:27:42PM -0400, Julian Bourne wrote:
> OK, I verified several things with the 5.0.2 kernel:
> 
> (1) amd64 GENERIC (non xen) suffers as well
> (2) amd64 XEN_DOM0 suffers with or without Manuel's patch
> (3) uvm_pglistalloc has the boundary >= size check as well

OK; if uvm_pglistalloc had this check too, my patch won't help.
I'll see how this can be fixed. uvm(9) doesn't say that
uvm_pglistalloc() should not be called with a boundary smaller than
size. Maybe it needs to be fixed too

> 
> If I can throw in 2c, I think the problem is that the bouncebuf
> create call should be using the max segment size from the sc
> structure, not MAXPHYS, but I admit, I'm way out of my depth.

It would then need to create the segment list by itself, where
we already have code to handle this.

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--