Re: port-i386/38935: x86 bus_dmamap_sync() should use memory barrier

[Andrew Doran <ad%netbsd.org@localhost>]

The following reply was made to PR port-i386/38935; it has been noted by GNATS.

From: Andrew Doran <ad%netbsd.org@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: 
Subject: Re: port-i386/38935: x86 bus_dmamap_sync() should use memory barrier
Date: Tue, 10 Jun 2008 22:25:12 +0100

 On Tue, Jun 10, 2008 at 09:20:02PM +0000, Andrew Doran wrote:
 
 >  I think x86_lfence() without any if() would be enough. Does it solve the
 >  problem for you?
 
 Bah, that will always evaluate to the equivalent of x86_mfence(). For this,
 membar_consumer() would a be better test since it will be patched to 'lfence'
 during boot.
 
 Andrew