[Intel-gfx] ✗ Fi.CI.BAT: failure for series starting with [1/4] dma-buf: add caching of sg_table

[Christian König]

Hi Daniel,

Am 18.07.2018 um 14:07 schrieb Patchwork:
> == Series Details ==
>
> Series: series starting with [1/4] dma-buf: add caching of sg_table
> URL   : https://patchwork.freedesktop.org/series/46778/
> State : failure
> [SNIP]

it looks like I'm a step further understanding the problems which come 
with this change.

I've more or less audited all use cases and think that only i915 is left 
with the following lock inversion: 
https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_9705/fi-cfl-8700k/igt@gem_mmap_gtt@basic-small-bo-tiledx.html

Now my question is what is &obj->mm.lock used for and why do you guys 
call dma_buf_map_attachment() while holding it?

Thanks in advance,
Christian.