lkml.org 
[lkml]   [2020]   [Sep]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: linux-next: build failure after merge of the drm tree


Le lun. 28 sept. 2020 à 13:34, Christoph Hellwig <hch@lst.de> a écrit
:
> On Mon, Sep 28, 2020 at 12:15:56PM +0200, Paul Cercueil wrote:
>> Hi Christoph,
>>
>> Le lun. 28 sept. 2020 à 8:04, Christoph Hellwig <hch@lst.de> a
>> écrit :
>>> On Mon, Sep 28, 2020 at 01:54:05PM +1000, Stephen Rothwell wrote:
>>>> Hi all,
>>>>
>>>> After merging the drm tree, today's linux-next build (x86_64
>>>> allmodconfig)
>>>> failed like this:
>>>
>>> The driver needs to switch do dma_alloc_noncoherent +
>>> dma_sync_single*
>>> like the other drivers converted in the dma tree. Paul, let me
>>> know if
>>> you have any questions.
>>
>> I don't dma_alloc* anything, DRM core does. I use the
>> DMA_ATTR_NON_CONSISTENT attr with dma_mmap_attrs(). Is there a
>> replacement
>> for that?
>
> dma_mmap_attrs can only be used on allocations from dma_mmap_attrs
> with
> the same attrs. As there is no allocation using
> DMA_ATTR_NON_CONSISTENT
> in the drm core, something looks very fishy here.

Is that a fact? I don't see why you couldn't change the cache settings
after allocation. In practice it works just fine.

> Where does the allocation you try to mmap come from? All the
> allocations
> in drivers/gpu/drm/drm_gem_cma_helper.c seems to use dma_alloc_wc (aka
> dma_allloc_attrs with the DMA_ATTR_WRITE_COMBINE flag).

It's the dma_alloc_wc.

-Paul


\
 
 \ /
  Last update: 2020-09-28 13:48    [W:0.054 / U:34.292 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site