lkml.org 
[lkml]   [2009]   [Sep]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRE: [PATCH 01/18] dmaengine: add fence support
Williams, Dan J wrote:
> Some engines optimize operation by reading ahead in the descriptor chain
> such that descriptor2 may start execution before descriptor1 completes.
> If descriptor2 depends on the result from descriptor1 then a fence is
> required (on descriptor2) to disable this optimization. The async_tx
> api could implicitly identify dependencies via the 'depend_tx'
> parameter, but that would constrain cases where the dependency chain
> only specifies a completion order rather than a data dependency. So,
> provide an ASYNC_TX_FENCE to explicitly identify data dependencies.
>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
> ---

Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com>

\
 
 \ /
  Last update: 2009-09-15 18:11    [from the cache]
©2003-2011 Jasper Spaans