[lkml]   [2020]   [Feb]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH v5 1/3] drm/shmem: add support for per object caching flags.

> > So I'd like to push patches 1+2 to -fixes and sort everything else later
> > in -next. OK?
> OK with me.


>> [ context: why shmem helpers use pgprot_writecombine + pgprot_decrypted?
>> we get conflicting mappings because of that, linear kernel
>> map vs. gem object vmap/mmap ]

> Do we have any idea what drivers are actually using
> write-combine and decrypted?

drivers/gpu/drm# find -name Kconfig* -print | xargs grep -l DRM_GEM_SHMEM_HELPER

virtio needs cached.
cirrus+udl should be ok with cached too.

Not clue about the others (lima, tiny, panfrost, v3d). Maybe they use
write-combine just because this is what they got by default from
drm_gem_mmap_obj(). Maybe they actually need that. Trying to Cc:
maintainters (and drop stable@).

On decrypted: I guess that is only relevant for virtual machines, i.e.
virtio-gpu and cirrus?

virtio-gpu needs it, otherwise the host can't show the virtual display.
cirrus bounces everything via blits to vram, so it should be ok without
decrypted. I guess that implies we should make decrypted configurable.


 \ /
  Last update: 2020-02-27 14:22    [W:0.072 / U:0.872 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site