[PATCH 01/13] drm/amdgpu: introduce and honour DRM_FORCE_AUTH workaround

[Daniel Vetter]

On Fri, Jun 21, 2019 at 12:31 PM Koenig, Christian
<Christian.Koenig at amd.com> wrote:
> Am 21.06.19 um 12:20 schrieb Emil Velikov:
> > In particular, that user-space will "remove" render nodes.
>
> Yes, that is my main concern here. You basically make render nodes
> superfluously. That gives userspace all legitimization to also remove
> support for them. That is not stupid or evil or whatever, userspace
> would just follow the kernel design.

This already happened. At least for kms-only display socs we had to
hide the separate render node (and there you really have to deal with
the separate render node, because it's a distinct driver) entirely
within gbm/mesa.

So if you want to depracate render functionality on primary nodes, you
_have_ to do that hiding in userspace. Or you'll break a lot of
compositors everywhere. Just testing -amdgpu doesn't really prove
anything here. So you won't move the larger ecosystem with this at
all, that ship sailed.

At that point this all feels like a bikeshed, and for a bikeshed I
don't care what the color is we pick, as long as they're all painted
the same.

Once we picked a color it's a simple technical matter of how to roll
it out, using Kconfig options, or only enabling on new hw, or "merge
and fix the regressions as they come" or any of the other well proven
paths forward.

So if you want to do this, please start with the mesa side work (as
the biggest userspace, not all of it) with patches to redirect all
primary node rendering to render nodes. The code is there already for
socs, just needs to be rolled out more. Or we go with the DRM_AUTH
horrors. Or a 3rd option, I really don't care which it is, as long as
its consistent.

tldr; consistent color choice on this bikeshed please.

Thanks, Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch