DMA to Userspace

[Mulyadi Santosa]

On Tue, Feb 8, 2011 at 02:42, Nikolaus Rath <Nikolaus at rath.org> wrote:
> I figured this one out myself, get_user_pages and dma_map_page do not
> create a mapping in kernel space for the buffer.

uhm, I recall when I read the get_user_pages function, it's kinda
"please pin those pages in RAM, don't let it paged out"....but the
mapping is still in user space AFAIK

>With
>
>    info("VI Start: 0x%0x", ((uint32_t*) kmap(acq_dev->vi_pg))[0]);
>    kunmap(acq_dev->vi_pg);

Nice!

> it works just fine. And for some reason, now my original problem has
> magically disappeared as well. Maybe it got scared by the suddenly
> immediate threat of being debugged :-).

If this is Facebook, I'll put "Like (this post)" on your post above :D

-- 
regards,

Mulyadi Santosa
Freelance Linux trainer and consultant

blog: the-hydra.blogspot.com
training: mulyaditraining.blogspot.com