On Friday, June 3rd, 2022 at 17:17, Zack Rusin <zackr@xxxxxxxxxx> wrote: > > > On Jun 3, 2022, at 10:56 AM, Simon Ser <contact@xxxxxxxxxxx> wrote: > > ⚠ External Email > > > > On Friday, June 3rd, 2022 at 16:38, Zack Rusin <zackr@xxxxxxxxxx> wrote: > > > > > > On Jun 3, 2022, at 10:32 AM, Simon Ser <contact@xxxxxxxxxxx> wrote: > > > > > > > > ⚠ External Email > > > > > > > > On Friday, June 3rd, 2022 at 16:27, Zack Rusin <zackr@xxxxxxxxxx> wrote: > > > > > > > > > > In particular: since the driver will ignore the KMS cursor plane > > > > > > position set by user-space, I don't think it's okay to just expose > > > > > > without opt-in from user-space (e.g. with a DRM_CLIENT_CAP). > > > > > > > > > > > > cc wayland-devel and Pekka for user-space feedback. > > > > > > > > > > I think Thomas expressed our concerns and reasons why those wouldn’t > > > > > work for us back then. Is there something else you’d like to add? > > > > > > > > I disagreed, and I don't understand Thomas' reasoning. > > > > > > > > KMS clients will need an update to work correctly. Adding a new prop > > > > without a cap leaves existing KMS clients broken. Adding a cap allows > > > > both existing KMS clients and updated KMS clients to work correctly. > > > > > > I’m not sure what you mean here. They are broken right now. That’s what we’re > > > fixing. That’s the reason why the virtualized drivers are on deny-lists for > > > all atomic kms. So nothing needs to be updated. If you have a kms client that > > > was using virtualized drivers with atomic kms then mouse clicks never worked > > > correctly. > > > > > > So, yes, clients need to set cursor hotspot if they want mouse to work > > > correctly with virtualized drivers. > > > > My proposal was: > > > > - Introduce DRM_CLIENT_CAP_CURSOR_PLANE_NO_POSITION (or a better name). Only > > user-space which supports the hotspot props will enable it. > > - By default, don't expose a cursor plane, because current user-space doesn't > > support it (Weston might put a window in the cursor plane, and nobody can > > report hotspot). > > - If the KMS client enables the cap, advertise the cursor > > plane, and make it so the plane doesn't have the CRTC_X/CRTC_Y properties > > since the driver will pick the position. > > > > That way both old and new user-space are fixed. > > I don’t think I see how that fixes anything. In particular I don’t see a way > of fixing the old user space at all. We require hotspot info, old user space > doesn’t set it because there’s no way of setting it on atomic kms. Old atomic user-space is fixed by removing the cursor plane. Then old atomic user-space will fallback to drawing the cursor itself, e.g. via OpenGL. New user-space supports setting the hotspot prop, and is aware that it can't set the cursor plane position, so the cursor plane can be exposed again when the cap is enabled.
