From df70b81ed7d8d80043b016b406ce79b1f1995af0 Mon Sep 17 00:00:00 2001 From: Marius Vlad Date: Sat, 4 Feb 2023 19:59:33 +0200 Subject: [PATCH] backend-drm: Do not overwrite plane's index when creating virtual plane Starting with commit 4cde507be6a116 "backend-drm: fix plane sorting" the plane list will have a descending order of the planes rather than ascending. This reversed order had the side-effect of exposing the fact that we don't set-up a plane index when creating the drm_plane using the DRM virtual API. Without settting a plane index for that drm_plane we effectively overwrite the plane index which has the 0 (zero) entry. This wasn't an issue before commit 4cde507be6a116 "backend-drm: fix plane sorting" as it seems we never picked up that plane index as being a suitable one due to the fact that those were assigned to primary planes, but after that commit, the cursor plane will be one getting the 0 (zero) plane index. Finally, this would trip over because we attempt to place a (cursor) view on a primary plane (where it would've normally be a cursor plane) and we end up with no framebuffer ref. This is fixed trivially by assigning a plane index, different than the ones already created by create_spirtes(). Signed-off-by: Marius Vlad (cherry picked from commit 27ce9dadd8865b266f72f848b784d61aeaf8b228) --- libweston/backend-drm/drm-virtual.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/libweston/backend-drm/drm-virtual.c b/libweston/backend-drm/drm-virtual.c index cf8de76a..931cb822 100644 --- a/libweston/backend-drm/drm-virtual.c +++ b/libweston/backend-drm/drm-virtual.c @@ -81,6 +81,20 @@ drm_virtual_crtc_destroy(struct drm_crtc *crtc) free(crtc); } +static uint32_t +get_drm_plane_index_maximum(struct drm_device *device) +{ + uint32_t max = 0; + struct drm_plane *p; + + wl_list_for_each(p, &device->plane_list, link) { + if (p->plane_idx > max) + max = p->plane_idx; + } + + return max; +} + /** * Create a drm_plane for virtual output * @@ -125,6 +139,7 @@ drm_virtual_plane_create(struct drm_device *device, struct drm_output *output) goto err; weston_plane_init(&plane->base, b->compositor, 0, 0); + plane->plane_idx = get_drm_plane_index_maximum(device) + 1; wl_list_insert(&device->plane_list, &plane->link); return plane;