lkml.org 
[lkml]   [2011]   [Sep]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: dma_unmap_single() lacking cache sync on some archs?
On Thu, 22 Sep 2011, Arvid Brodin wrote:

> Hi,
>
> I would expect cache synchronization for DMA_TO_DEVICE and DMA_BIDIRECTIONAL
> when dma_map_single() is called, and for DMA_FROM_DEVICE and DMA_BIDIRECTIONAL
> when dma_unmap_single() is called.
>
> However, on some architechtures (at least avr32, blackfin, ...), cache
> synchronization only happens when dma_map_single() is called (and then
> irrespective of DMA direction). dma_unmap_single() is a no-op for these archs.
>
> Isn't this a bug?

You'd get a better chance to reach your audience by cc'ing respective arch
mailing lists and at least the linux-embedded@vger.kernel.org ML.

Thanks
Guennadi

> (Please CC me in responses.)
>
> --
> Arvid Brodin
> Enea Services Stockholm AB

---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/


\
 
 \ /
  Last update: 2011-09-23 00:09    [from the cache]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and my Meterkast|Read the blog