[PATCH 3/4] drm/imx: add FB modifier support

[Daniel Stone]

Hi,

On 4 May 2017 at 09:59, Lucas Stach <l.stach at pengutronix.de> wrote:
> Am Mittwoch, den 03.05.2017, 18:15 +0100 schrieb Daniel Stone:
>> What about planes which aren't present in this commit, but are still
>> taking up a PRE unit? Will they have their PRE stolen, or am I missing
>> something?
>
> Yes, the plane->PRE assignment is configurable by matching different AXI
> IDs in the PRG. So what's happening here is that we basically construct
> a new assignment for each commit. Planes without a assigned PRE will
> revert back to pass-through mode in the PRG on plane commit or plane
> disable.

So those other planes are fine/untouched, because the PRE has already
resolved to linear? Specifically if plane A has a tiled FB, then
userspace does a commit which _only_ contains plane B (also with a
tiled FB), and plane B steals the PRE that was previously assigned to
plane A, then plane A continues displaying just fine? Sorry for the
stupid questions. :)

Cheers,
Daniel