backend/drm: fix GBM format mismatch

We create the EGL config with GBM_FORMAT_ARGB8888, but then initialize GBM BOs
with GBM_FORMAT_XRGB8888. This mismatch confuses Mesa.

Instead, we can always use GBM_FORMAT_ARGB8888, and use DRM_FORMAT_XRGB8888
when calling drmModeAddFB2.

Fixes https://github.com/swaywm/wlroots/issues/1438

1 files changed, 2 insertions, 0 deletions

diff --git a/include/backend/drm/renderer.h b/include/backend/drm/renderer.h
index 575758de..25b07b97 100644
--- a/include/backend/drm/renderer.h
+++ b/include/backend/drm/renderer.h
@@ -16,6 +16,8 @@ struct wlr_drm_renderer {
 	struct gbm_device *gbm;
 	struct wlr_egl egl;
 
+	uint32_t gbm_format;
+
 	struct wlr_renderer *wlr_rend;
 };