Am Donnerstag, den 04.05.2017, 10:02 +0100 schrieb Daniel Stone:
Hi,
On 4 May 2017 at 09:59, Lucas Stach l.stach@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. :)
If userspace does a commit with only plane B it's going to disable plane A, right? The PRG/PRE register sets are double buffered (or at least we always use them in this mode). So if plane B steals the PRE from plane A, which is going to get disabled, plane A will continue to use the PRE until the end of frame, then the register set will be latched and the PRE is switched to plane B for the next frame.
Regards, Lucas