Hi, On Tue, 13 Feb 2024 at 10:18, Marius Vlad <marius.vlad@xxxxxxxxxxxxx> wrote: > On Tue, Feb 13, 2024 at 11:57:59AM +0200, Tomi Valkeinen wrote: > > I haven't. I'm quite unfamiliar with Weston, and Randolph from TI (cc'd) has > > been working on the Weston side of things. I also don't know if there's > > something TI specific here, as the use case is with non-mainline GPU drivers > > and non-mainline Mesa. I should have been a bit clearer in the patch > > description, as I didn't mean that upstream Weston has a bug (maybe it has, > > maybe it has not). Don't worry about it. We've had bugs in the past and I'm sure we'll have more. :) Either way, it's definitely better to have the kernel expose sensible behaviour rather than weird workarounds, unless they've been around for so long that they're basically baked into ABI. > > The issue seen is that when Weston decides to use DRM planes for > > composition, the plane zpositions are not configured correctly (or at all?). > > Afaics, this leads to e.g. weston showing a window with a DRM "overlay" > > plane that is behind the "primary" root plane, so the window is not visible. > > And as Weston thinks that the area supposedly covered by the overlay plane > > does not need to be rendered on the root plane, there are also artifacts on > > that area. > > > > Also, the Weston I used is a bit older one (10.0.1), as I needed to go back > > in my buildroot versions to get all that non-mainline GPU stuff compiled and > > working. A more recent Weston may behave differently. > > Right after Weston 10, we had a few minor changes related to the > zpos-sorting list of planes and how we parse the plan list without having > a temporary zpos ordered list to pick planes from. > > And there's another fix for missing out to set out the zpos for scanout > to the minimum available - which seems like a good candidate to explain > what happens in the issue described above. So if trying Weston again, > please try with at least Weston 12, which should have those changes > in. Specifically, you probably want commits 4cde507be6a1 and 58dde0e0c000. I think the window of breakage was small enough that - assuming either those commits or an upgrade to Weston 12/13 fixes it - we can just ask people to upgrade to a fixed Weston. > > Presuming this is not related to any TI specific code, I guess it's a > > regression in the sense that at some point Weston added the support to use > > planes for composition, so previously with only a single plane per display > > there was no issue. That point was 12 years ago, so not that novel. ;) Cheers, Daniel
