lkml.org 
[lkml]   [2021]   [Jun]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCHv2 8/8] videobuf2: handle non-contiguous DMA allocations
On Thu, Jun 17, 2021 at 7:07 PM Christoph Hellwig <hch@lst.de> wrote:
>
> On Thu, Jun 17, 2021 at 06:40:58PM +0900, Tomasz Figa wrote:
> > Sorry, I meant dma_alloc_attrs() and yes, it's indeed a misnomer. Our
> > use case basically has no need for the additional coherent mapping, so
> > creation of it can be skipped to save some vmalloc space. (Yes, it
> > probably only matters for 32-bit architectures.)
>
> Yes, that is the normal use case, and it is solved by using
> dma_alloc_noncoherent or dma_alloc_noncontigous without the vmap
> step.

True, silly me. Probably not enough coffee at the time I was looking at it.

With that, wouldn't it be possible to completely get rid of
dma_alloc_{coherent,attrs}() and use dma_alloc_noncontiguous() +
optional kernel and/or userspace mapping helper everywhere? (Possibly
renaming it to something as simple as dma_alloc().

\
 
 \ /
  Last update: 2021-06-18 05:23    [W:0.079 / U:0.328 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site