Merge branch 'master' into librem5-master-3

.builds/freebsd.yml

-image: freebsd
+image: freebsd/latest
 packages:
-- devel/automake
+- devel/evdev-proto
+- devel/libepoll-shim
+- devel/libudev-devd
+- devel/meson # implies ninja
+- devel/pkgconf
+- graphics/libdrm
+- graphics/mesa-libs
+- graphics/png
+- graphics/wayland
+- graphics/wayland-protocols
 - multimedia/ffmpeg
-- devel/gmake
-- devel/json-c
-- devel/libtool
+- x11/libX11
+- x11/libinput
+- x11/libxcb
 - x11/libxkbcommon
-- textproc/libxslt
-- x11-toolkits/pango
-- devel/pkgconf
-- print/texinfo
-- x11/xcb-util-image
+- x11/pixman
+# - x11/xcb-util-errors # too recent, not in /quarterly
 - x11/xcb-util-wm
-- python36
-- py36-setuptools
 sources:
 - https://github.com/swaywm/wlroots
 tasks:
-- setup: |
-    # Don't build unnecessary stuff
-    echo "OPTIONS_UNSET+= NLS DOCS EXAMPLES LIBWACOM" | sudo tee -a /etc/make.conf
-    # Note: this could probably be set in the FreeBSD base image
-    echo "BATCH=yes" | sudo tee -a /etc/make.conf
-- ports_tree: |
-    # This is ugly, but fetching and extracting the whole ports tree takes a
-    # really-really long time...
-    # First we need a clean tree, and renaming is faster than deleting.
-    sudo mv /usr/ports /usr/ports.orig
-    sudo mkdir /usr/ports
-    # Fetch only needed ports
-    sudo svnlite export --force https://svn.FreeBSD.org/ports/head/GIDs /usr/ports/GIDs
-    sudo svnlite export --force https://svn.FreeBSD.org/ports/head/Keywords /usr/ports/Keywords
-    sudo svnlite export --force https://svn.FreeBSD.org/ports/head/Makefile /usr/ports/Makefile
-    sudo svnlite export --force https://svn.FreeBSD.org/ports/head/Mk /usr/ports/Mk
-    sudo svnlite export --force https://svn.FreeBSD.org/ports/head/Templates /usr/ports/Templates
-    sudo svnlite export --force https://svn.FreeBSD.org/ports/head/Tools /usr/ports/Tools
-    sudo svnlite export --force https://svn.FreeBSD.org/ports/head/UIDs /usr/ports/UIDs
-    sudo svnlite export --force https://svn.FreeBSD.org/ports/head/devel/libevdev /usr/ports/devel/libevdev
-    sudo svnlite export --force https://svn.FreeBSD.org/ports/head/devel/libmtdev /usr/ports/devel/libmtdev
-    sudo svnlite export --force https://svn.FreeBSD.org/ports/head/devel/libudev-devd /usr/ports/devel/libudev-devd
-    sudo svnlite export --force https://svn.FreeBSD.org/ports/head/devel/meson /usr/ports/devel/meson
-    sudo svnlite export --force https://svn.FreeBSD.org/ports/head/devel/ninja /usr/ports/devel/ninja
-    sudo svnlite export --force https://svn.FreeBSD.org/ports/head/devel/py-evdev /usr/ports/devel/py-evdev
-    sudo svnlite export --force https://svn.FreeBSD.org/ports/head/devel/py-six /usr/ports/devel/py-six
-    sudo svnlite export --force https://svn.FreeBSD.org/ports/head/graphics/wayland-protocols /usr/ports/graphics/wayland-protocols
-    sudo svnlite export --force https://svn.FreeBSD.org/ports/head/graphics/wayland /usr/ports/graphics/wayland
-    sudo svnlite export --force https://svn.FreeBSD.org/ports/head/lang/python27 /usr/ports/lang/python27
-    sudo svnlite export --force https://svn.FreeBSD.org/ports/head/lang/python36 /usr/ports/lang/python36
-- fixup_libinput: |
-    sudo svnlite export https://github.com/FreeBSDDesktop/freebsd-ports/branches/feature/input/devel/libepoll-shim /usr/ports/devel/libepoll-shim
-    sudo svnlite export https://github.com/FreeBSDDesktop/freebsd-ports/branches/feature/input/x11/libinput /usr/ports/x11/libinput
-    sudo svnlite export https://github.com/FreeBSDDesktop/freebsd-ports/branches/feature/input/devel/evdev-proto /usr/ports/devel/evdev-proto
-    sudo svnlite export https://github.com/FreeBSDDesktop/freebsd-ports/branches/feature/input/devel/py-pyudev /usr/ports/devel/py-pyudev
-- ports_build: |
-    cd /usr/ports/graphics/wayland-protocols/ && sudo make install
-    cd /usr/ports/x11/libinput/ && sudo make install clean
-    # v4l_compat is a dependency of libinput, but the version in the ports tree
-    # conflicts with the new evdev-proto. It can be safely removed though.
-    sudo pkg remove -fy v4l_compat
-    cd /usr/ports/devel/evdev-proto && sudo make install clean
 - fixup_epoll: |
     cat << 'EOF' | sudo tee /usr/local/libdata/pkgconfig/epoll-shim.pc
     prefix=/usr/local
@@ -70,7 +32,8 @@ tasks:
     Description: epoll shim implemented using kevent
     Version: 0
     Requires:
-    Libs: -L${libdir} -L${sharedlibdir} -lepoll-shim -lthr
+    Libs: -L${libdir} -L${sharedlibdir} -lepoll-shim
+    Libs.private: -pthread -lrt
     Cflags: -I${includedir}
     EOF
 - wlroots: |

.editorconfig

@@ -4,8 +4,9 @@ root = true
 end_of_line = lf
 insert_final_newline = true
 charset = utf-8
-indent_style = tab
 trim_trailing_whitespace = true
+indent_style = tab
+indent_size = 4
 
 [*.xml]
 indent_style = space

.gitignore

@@ -5,6 +5,7 @@ bin/
 test/
 build/
 _build/
+build-*/
 wayland-*-protocol.*
 wlr-example.ini
 rootston.ini

README.md

@@ -78,21 +78,6 @@ Install like so:
 
 	sudo ninja -C build install
 
-## Running the test compositor
-
-wlroots comes with a test compositor called rootston, which demonstrates the
-features of the library and is used as a testbed for the development of the
-library. It may also be useful as a reference for understanding how to use
-various wlroots features, but it's not considered a production-quality codebase
-and is not designed for daily use.
-
-If you followed the build instructions above the rootston executable can be
-found at `./build/rootston/rootston`. To use it, refer to the example config at
-[./rootston/rootston.ini.example](https://github.com/swaywm/wlroots/blob/master/rootston/rootston.ini.example)
-and place a config file of your own at `rootston.ini` in the working directory
-(or in an arbitrary location via `rootston -C`). Other options are available,
-refer to `rootston -h`.
-
 ## Contributing
 
 The Librem5 version of wlroots repository is structured in a particular way. The procedure is described in the [CONTRIBUTING-librem5.md](https://source.puri.sm/Librem5/wlroots/blob/librem5/CONTRIBUTING-librem5.md) file.

backend/backend.c

@@ -11,6 +11,7 @@
 #include <wlr/backend/interface.h>
 #include <wlr/backend/libinput.h>
 #include <wlr/backend/multi.h>
+#include <wlr/backend/noop.h>
 #include <wlr/backend/session.h>
 #include <wlr/backend/wayland.h>
 #include <wlr/config.h>
@@ -133,6 +134,20 @@ static struct wlr_backend *attempt_headless_backend(
 	return backend;
 }
 
+static struct wlr_backend *attempt_noop_backend(struct wl_display *display) {
+	struct wlr_backend *backend = wlr_noop_backend_create(display);
+	if (backend == NULL) {
+		return NULL;
+	}
+
+	size_t outputs = parse_outputs_env("WLR_NOOP_OUTPUTS");
+	for (size_t i = 0; i < outputs; ++i) {
+		wlr_noop_add_output(backend);
+	}
+
+	return backend;
+}
+
 static struct wlr_backend *attempt_drm_backend(struct wl_display *display,
 		struct wlr_backend *backend, struct wlr_session *session,
 		wlr_renderer_create_func_t create_renderer_func) {
@@ -170,6 +185,8 @@ static struct wlr_backend *attempt_backend_by_name(struct wl_display *display,
 #endif
 	} else if (strcmp(name, "headless") == 0) {
 		return attempt_headless_backend(display, create_renderer_func);
+	} else if (strcmp(name, "noop") == 0) {
+		return attempt_noop_backend(display);
 	} else if (strcmp(name, "drm") == 0 || strcmp(name, "libinput") == 0) {
 		// DRM and libinput need a session
 		if (!*session) {

backend/drm/atomic.c

@@ -172,7 +172,8 @@ static bool atomic_crtc_set_cursor(struct wlr_drm_backend *drm,
 	atomic_begin(crtc, &atom);
 
 	if (bo) {
-		set_plane_props(&atom, plane, crtc->id, get_fb_for_bo(bo), false);
+		uint32_t fb_id = get_fb_for_bo(bo, plane->drm_format);
+		set_plane_props(&atom, plane, crtc->id, fb_id, false);
 	} else {
 		atomic_add(&atom, plane->id, plane->props.fb_id, 0);
 		atomic_add(&atom, plane->id, plane->props.crtc_id, 0);

backend/drm/backend.c

@@ -104,7 +104,7 @@ static void session_signal(struct wl_listener *listener, void *data) {
 
 			struct wlr_drm_plane *plane = conn->crtc->cursor;
 			drm->iface->crtc_set_cursor(drm, conn->crtc,
-				(plane && plane->cursor_enabled) ? plane->cursor_bo : NULL);
+				(plane && plane->cursor_enabled) ? plane->surf.back : NULL);
 			drm->iface->crtc_move_cursor(drm, conn->crtc, conn->cursor_x,
 				conn->cursor_y);
 

backend/drm/drm.c

 #define _POSIX_C_SOURCE 200112L
 #include <assert.h>
+#include <drm_fourcc.h>
 #include <drm_mode.h>
 #include <EGL/egl.h>
 #include <EGL/eglext.h>
@@ -109,8 +110,8 @@ static bool init_planes(struct wlr_drm_backend *drm) {
 
 		p->id = plane->plane_id;
 		p->possible_crtcs = plane->possible_crtcs;
-		uint64_t type;
 
+		uint64_t type;
 		if (!get_drm_plane_props(drm->fd, p->id, &p->props) ||
 				!get_drm_prop(drm->fd, p->id, p->props.type, &type)) {
 			drmModeFreePlane(plane);
@@ -120,6 +121,25 @@ static bool init_planes(struct wlr_drm_backend *drm) {
 		p->type = type;
 		drm->num_type_planes[type]++;
 
+		// Choose an RGB format for the plane
+		uint32_t rgb_format = DRM_FORMAT_INVALID;
+		for (size_t j = 0; j < plane->count_formats; ++j) {
+			uint32_t fmt = plane->formats[j];
+			if (fmt == DRM_FORMAT_ARGB8888) {
+				// Prefer formats with alpha channel
+				rgb_format = fmt;
+				break;
+			} else if (fmt == DRM_FORMAT_XRGB8888) {
+				rgb_format = fmt;
+			}
+		}
+		if (rgb_format == DRM_FORMAT_INVALID) {
+			wlr_log(WLR_ERROR, "Failed to find an RGB format for plane %zu", i);
+			drmModeFreePlane(plane);
+			goto error_planes;
+		}
+		p->drm_format = rgb_format;
+
 		drmModeFreePlane(plane);
 	}
 
@@ -206,12 +226,6 @@ void finish_drm_resources(struct wlr_drm_backend *drm) {
 		}
 		free(crtc->gamma_table);
 	}
-	for (size_t i = 0; i < drm->num_planes; ++i) {
-		struct wlr_drm_plane *plane = &drm->planes[i];
-		if (plane->cursor_bo) {
-			gbm_bo_destroy(plane->cursor_bo);
-		}
-	}
 
 	free(drm->crtcs);
 	free(drm->planes);
@@ -247,7 +261,7 @@ static bool drm_connector_swap_buffers(struct wlr_output *output,
 	if (drm->parent) {
 		bo = copy_drm_surface_mgpu(&plane->mgpu_surf, bo);
 	}
-	uint32_t fb_id = get_fb_for_bo(bo);
+	uint32_t fb_id = get_fb_for_bo(bo, plane->drm_format);
 
 	if (conn->pageflip_pending) {
 		wlr_log(WLR_ERROR, "Skipping pageflip on output '%s'", conn->output.name);
@@ -366,7 +380,7 @@ static void drm_connector_start_renderer(struct wlr_drm_connector *conn) {
 
 	struct gbm_bo *bo = get_drm_surface_front(
 		drm->parent ? &plane->mgpu_surf : &plane->surf);
-	uint32_t fb_id = get_fb_for_bo(bo);
+	uint32_t fb_id = get_fb_for_bo(bo, plane->drm_format);
 
 	struct wlr_drm_mode *mode = (struct wlr_drm_mode *)conn->output.current_mode;
 	if (drm->iface->crtc_pageflip(drm, conn, crtc, fb_id, &mode->drm_mode)) {
@@ -391,6 +405,8 @@ static void attempt_enable_needs_modeset(struct wlr_drm_backend *drm) {
 		if (conn->state == WLR_DRM_CONN_NEEDS_MODESET &&
 				conn->crtc != NULL && conn->desired_mode != NULL &&
 				conn->desired_enabled) {
+			wlr_log(WLR_DEBUG, "Output %s has a desired mode and a CRTC, "
+				"attempting a modeset", conn->output.name);
 			drm_connector_set_mode(&conn->output, conn->desired_mode);
 		}
 	}
@@ -526,7 +542,7 @@ static bool drm_connector_set_mode(struct wlr_output *output,
 		conn->output.name, mode->width, mode->height, mode->refresh);
 
 	if (!init_drm_plane_surfaces(conn->crtc->primary, drm,
-			mode->width, mode->height, GBM_FORMAT_XRGB8888)) {
+			mode->width, mode->height, drm->renderer.gbm_format)) {
 		wlr_log(WLR_ERROR, "Failed to initialize renderer for plane");
 		return false;
 	}
@@ -550,11 +566,18 @@ bool wlr_drm_connector_add_mode(struct wlr_output *output,
 		const drmModeModeInfo *modeinfo) {
 	struct wlr_drm_connector *conn = get_drm_connector_from_output(output);
 
-	assert(modeinfo);
 	if (modeinfo->type != DRM_MODE_TYPE_USERDEF) {
 		return false;
 	}
 
+	struct wlr_output_mode *wlr_mode;
+	wl_list_for_each(wlr_mode, &conn->output.modes, link) {
+		struct wlr_drm_mode *mode = (struct wlr_drm_mode *)wlr_mode;
+		if (memcmp(&mode->drm_mode, modeinfo, sizeof(*modeinfo)) == 0) {
+			return true;
+		}
+	}
+
 	struct wlr_drm_mode *mode = calloc(1, sizeof(*mode));
 	if (!mode) {
 		return false;
@@ -563,7 +586,7 @@ bool wlr_drm_connector_add_mode(struct wlr_output *output,
 
 	mode->wlr_mode.width = mode->drm_mode.hdisplay;
 	mode->wlr_mode.height = mode->drm_mode.vdisplay;
-	mode->wlr_mode.refresh = mode->drm_mode.vrefresh;
+	mode->wlr_mode.refresh = calculate_refresh_rate(modeinfo);
 
 	wlr_log(WLR_INFO, "Registered custom mode "
 			"%"PRId32"x%"PRId32"@%"PRId32,
@@ -609,20 +632,25 @@ static bool drm_connector_set_cursor(struct wlr_output *output,
 		ret = drmGetCap(drm->fd, DRM_CAP_CURSOR_HEIGHT, &h);
 		h = ret ? 64 : h;
 
-		struct wlr_drm_renderer *renderer =
-			drm->parent ? &drm->parent->renderer : &drm->renderer;
 
-		if (!init_drm_surface(&plane->surf, renderer, w, h,
-				GBM_FORMAT_ARGB8888, 0)) {
-			wlr_log(WLR_ERROR, "Cannot allocate cursor resources");
-			return false;
-		}
+		if (!drm->parent) {
+			if (!init_drm_surface(&plane->surf, &drm->renderer, w, h,
+					drm->renderer.gbm_format, GBM_BO_USE_LINEAR | GBM_BO_USE_SCANOUT)) {
+				wlr_log(WLR_ERROR, "Cannot allocate cursor resources");
+				return false;
+			}
+		} else {
+			if (!init_drm_surface(&plane->surf, &drm->parent->renderer, w, h,
+					drm->parent->renderer.gbm_format, GBM_BO_USE_LINEAR)) {
+				wlr_log(WLR_ERROR, "Cannot allocate cursor resources");
+				return false;
+			}
 
-		plane->cursor_bo = gbm_bo_create(drm->renderer.gbm, w, h,
-			GBM_FORMAT_ARGB8888, GBM_BO_USE_CURSOR | GBM_BO_USE_WRITE);
-		if (!plane->cursor_bo) {
-			wlr_log_errno(WLR_ERROR, "Failed to create cursor bo");
-			return false;
+			if (!init_drm_surface(&plane->mgpu_surf, &drm->renderer, w, h,
+					drm->renderer.gbm_format, GBM_BO_USE_LINEAR | GBM_BO_USE_SCANOUT)) {
+				wlr_log(WLR_ERROR, "Cannot allocate cursor resources");
+				return false;
+			}
 		}
 	}
 
@@ -630,8 +658,9 @@ static bool drm_connector_set_cursor(struct wlr_output *output,
 		plane->surf.height, output->transform);
 
 	struct wlr_box hotspot = { .x = hotspot_x, .y = hotspot_y };
-	wlr_box_transform(&hotspot, wlr_output_transform_invert(output->transform),
-		plane->surf.width, plane->surf.height, &hotspot);
+	wlr_box_transform(&hotspot, &hotspot,
+		wlr_output_transform_invert(output->transform),
+		plane->surf.width, plane->surf.height);
 
 	if (plane->cursor_hotspot_x != hotspot.x ||
 			plane->cursor_hotspot_y != hotspot.y) {
@@ -668,17 +697,6 @@ static bool drm_connector_set_cursor(struct wlr_output *output,
 			return false;
 		}
 
-		uint32_t bo_width = gbm_bo_get_width(plane->cursor_bo);
-		uint32_t bo_height = gbm_bo_get_height(plane->cursor_bo);
-
-		uint32_t bo_stride;
-		void *bo_data;
-		if (!gbm_bo_map(plane->cursor_bo, 0, 0, bo_width, bo_height,
-				GBM_BO_TRANSFER_WRITE, &bo_stride, &bo_data)) {
-			wlr_log_errno(WLR_ERROR, "Unable to map buffer");
-			return false;
-		}
-
 		make_drm_surface_current(&plane->surf, NULL);
 
 		struct wlr_renderer *rend = plane->surf.renderer->wlr_rend;
@@ -693,13 +711,8 @@ static bool drm_connector_set_cursor(struct wlr_output *output,
 		wlr_render_texture_with_matrix(rend, texture, matrix, 1.0);
 		wlr_renderer_end(rend);
 
-		wlr_renderer_read_pixels(rend, WL_SHM_FORMAT_ARGB8888, NULL, bo_stride,
-			plane->surf.width, plane->surf.height, 0, 0, 0, 0, bo_data);
-
 		swap_drm_surface_buffers(&plane->surf, NULL);
 
-		gbm_bo_unmap(plane->cursor_bo, bo_data);
-
 		plane->cursor_enabled = true;
 	}
 
@@ -707,7 +720,20 @@ static bool drm_connector_set_cursor(struct wlr_output *output,
 		return true; // will be committed when session is resumed
 	}
 
-	struct gbm_bo *bo = plane->cursor_enabled ? plane->cursor_bo : NULL;
+	struct gbm_bo *bo = plane->cursor_enabled ? plane->surf.back : NULL;
+	if (bo && drm->parent) {
+		bo = copy_drm_surface_mgpu(&plane->mgpu_surf, bo);
+	}
+
+	if (bo) {
+		// workaround for nouveau
+		// Buffers created with GBM_BO_USER_LINEAR are placed in NOUVEAU_GEM_DOMAIN_GART.
+		// When the bo is attached to the cursor plane it is moved to NOUVEAU_GEM_DOMAIN_VRAM.
+		// However, this does not wait for the render operations to complete, leaving an empty surface.
+		// see https://bugs.freedesktop.org/show_bug.cgi?id=109631
+		// The render operations can be waited for using:
+		glFinish();
+	}
 	bool ok = drm->iface->crtc_set_cursor(drm, crtc, bo);
 	if (ok) {
 		wlr_output_update_needs_swap(output);
@@ -731,7 +757,7 @@ static bool drm_connector_move_cursor(struct wlr_output *output,
 
 	enum wl_output_transform transform =
 		wlr_output_transform_invert(output->transform);
-	wlr_box_transform(&box, transform, width, height, &box);
+	wlr_box_transform(&box, &box, transform, width, height);
 
 	if (plane != NULL) {
 		box.x -= plane->cursor_hotspot_x;
@@ -776,7 +802,6 @@ static bool drm_connector_schedule_frame(struct wlr_output *output) {
 	if (drm->parent) {
 		bo = copy_drm_surface_mgpu(&plane->mgpu_surf, bo);
 	}
-	uint32_t fb_id = get_fb_for_bo(bo);
 
 	if (conn->pageflip_pending) {
 		wlr_log(WLR_ERROR, "Skipping pageflip on output '%s'",
@@ -784,6 +809,7 @@ static bool drm_connector_schedule_frame(struct wlr_output *output) {
 		return true;
 	}
 
+	uint32_t fb_id = get_fb_for_bo(bo, plane->drm_format);
 	if (!drm->iface->crtc_pageflip(drm, conn, crtc, fb_id, NULL)) {
 		return false;
 	}
@@ -974,13 +1000,22 @@ static void realloc_crtcs(struct wlr_drm_backend *drm, bool *changed_outputs) {
 		i++;
 		struct wlr_output_mode *mode = conn->output.current_mode;
 
-		if (conn->state != WLR_DRM_CONN_CONNECTED || !changed_outputs[i]
-				|| conn->crtc == NULL) {
+		if (conn->state != WLR_DRM_CONN_CONNECTED || !changed_outputs[i]) {
+			continue;
+		}
+
+		if (conn->crtc == NULL) {
+			wlr_log(WLR_DEBUG, "Output has %s lost its CRTC",
+				conn->output.name);
+			conn->state = WLR_DRM_CONN_NEEDS_MODESET;
+			wlr_output_update_enabled(&conn->output, false);
+			conn->desired_mode = conn->output.current_mode;
+			wlr_output_update_mode(&conn->output, NULL);
 			continue;
 		}
 
 		if (!init_drm_plane_surfaces(conn->crtc->primary, drm,
-				mode->width, mode->height, GBM_FORMAT_XRGB8888)) {
+				mode->width, mode->height, drm->renderer.gbm_format)) {
 			wlr_log(WLR_ERROR, "Failed to initialize renderer for plane");
 			drm_connector_cleanup(conn);
 			break;
@@ -992,36 +1027,43 @@ static void realloc_crtcs(struct wlr_drm_backend *drm, bool *changed_outputs) {
 	}
 }
 
-static uint32_t get_possible_crtcs(int fd, uint32_t conn_id) {
-	drmModeConnector *conn = drmModeGetConnector(fd, conn_id);
-	if (!conn) {
-		wlr_log_errno(WLR_ERROR, "Failed to get DRM connector");
-		return 0;
-	}
+static uint32_t get_possible_crtcs(int fd, drmModeRes *res,
+		drmModeConnector *conn, bool is_mst) {
+	uint32_t ret = 0;
 
-	if (conn->connection != DRM_MODE_CONNECTED || conn->count_modes == 0) {
-		wlr_log(WLR_ERROR, "Output is not connected");
-		goto error_conn;
+	for (int i = 0; i < conn->count_encoders; ++i) {
+		drmModeEncoder *enc = drmModeGetEncoder(fd, conn->encoders[i]);
+		if (!enc) {
+			continue;
+		}
+
+		ret |= enc->possible_crtcs;
+
+		drmModeFreeEncoder(enc);
 	}
 
-	drmModeEncoder *enc = NULL;
-	for (int i = 0; !enc && i < conn->count_encoders; ++i) {
-		enc = drmModeGetEncoder(fd, conn->encoders[i]);
+	// Sometimes DP MST connectors report no encoders, so we'll loop though
+	// all of the encoders of the MST type instead.
+	// TODO: See if there is a better solution.
+
+	if (!is_mst || ret) {
+		return ret;
 	}
 
-	if (!enc) {
-		wlr_log(WLR_ERROR, "Failed to get DRM encoder");
-		goto error_conn;
+	for (int i = 0; i < res->count_encoders; ++i) {
+		drmModeEncoder *enc = drmModeGetEncoder(fd, res->encoders[i]);
+		if (!enc) {
+			continue;
+		}
+
+		if (enc->encoder_type == DRM_MODE_ENCODER_DPMST) {
+			ret |= enc->possible_crtcs;
+		}
+
+		drmModeFreeEncoder(enc);
 	}
 
-	uint32_t ret = enc->possible_crtcs;
-	drmModeFreeEncoder(enc);
-	drmModeFreeConnector(conn);
 	return ret;
-
-error_conn:
-	drmModeFreeConnector(conn);
-	return 0;
 }
 
 void scan_drm_connectors(struct wlr_drm_backend *drm) {
@@ -1051,7 +1093,7 @@ void scan_drm_connectors(struct wlr_drm_backend *drm) {
 		drmModeEncoder *curr_enc = drmModeGetEncoder(drm->fd,
 			drm_conn->encoder_id);
 
-		int index = -1;
+		ssize_t index = -1;
 		struct wlr_drm_connector *c, *wlr_conn = NULL;
 		wl_list_for_each(c, &drm->outputs, link) {
 			index++;
@@ -1087,7 +1129,7 @@ void scan_drm_connectors(struct wlr_drm_backend *drm) {
 				wlr_conn->old_crtc = drmModeGetCrtc(drm->fd, curr_enc->crtc_id);
 			}
 
-			wl_list_insert(&drm->outputs, &wlr_conn->link);
+			wl_list_insert(drm->outputs.prev, &wlr_conn->link);
 			wlr_log(WLR_INFO, "Found connector '%s'", wlr_conn->output.name);
 		} else {
 			seen[index] = true;
@@ -1168,7 +1210,8 @@ void scan_drm_connectors(struct wlr_drm_backend *drm) {
 				wl_list_insert(&wlr_conn->output.modes, &mode->wlr_mode.link);
 			}
 
-			wlr_conn->possible_crtc = get_possible_crtcs(drm->fd, wlr_conn->id);
+			wlr_conn->possible_crtc = get_possible_crtcs(drm->fd, res, drm_conn,
+				wlr_conn->props.path != 0);
 			if (wlr_conn->possible_crtc == 0) {
 				wlr_log(WLR_ERROR, "No CRTC possible for connector '%s'",
 					wlr_conn->output.name);
@@ -1179,7 +1222,8 @@ void scan_drm_connectors(struct wlr_drm_backend *drm) {
 
 			wlr_conn->state = WLR_DRM_CONN_NEEDS_MODESET;
 			new_outputs[new_outputs_len++] = wlr_conn;
-		} else if (wlr_conn->state == WLR_DRM_CONN_CONNECTED &&
+		} else if ((wlr_conn->state == WLR_DRM_CONN_CONNECTED ||
+				wlr_conn->state == WLR_DRM_CONN_NEEDS_MODESET) &&
 				drm_conn->connection != DRM_MODE_CONNECTED) {
 			wlr_log(WLR_INFO, "'%s' disconnected", wlr_conn->output.name);
 
@@ -1192,9 +1236,11 @@ void scan_drm_connectors(struct wlr_drm_backend *drm) {
 
 	drmModeFreeResources(res);
 
+	// Iterate in reverse order because we'll remove items from the list and
+	// still want indices to remain correct.
 	struct wlr_drm_connector *conn, *tmp_conn;
 	size_t index = wl_list_length(&drm->outputs);
-	wl_list_for_each_safe(conn, tmp_conn, &drm->outputs, link) {
+	wl_list_for_each_reverse_safe(conn, tmp_conn, &drm->outputs, link) {
 		index--;
 		if (index >= seen_len || seen[index]) {
 			continue;

backend/drm/properties.c

@@ -22,6 +22,7 @@ static const struct prop_info connector_info[] = {
 	{ "CRTC_ID",     INDEX(crtc_id) },
 	{ "DPMS",        INDEX(dpms) },
 	{ "EDID",        INDEX(edid) },
+	{ "PATH",        INDEX(path) },
 	{ "link-status", INDEX(link_status) },
 #undef INDEX
 };

backend/drm/renderer.c

@@ -14,10 +14,6 @@
 #include "backend/drm/drm.h"
 #include "glapi.h"
 
-#ifndef DRM_FORMAT_MOD_LINEAR
-#define DRM_FORMAT_MOD_LINEAR 0
-#endif
-
 bool init_drm_renderer(struct wlr_drm_backend *drm,
 		struct wlr_drm_renderer *renderer, wlr_renderer_create_func_t create_renderer_func) {
 	renderer->gbm = gbm_create_device(drm->fd);
@@ -38,10 +34,10 @@ bool init_drm_renderer(struct wlr_drm_backend *drm,
 		EGL_NONE,
 	};
 
+	renderer->gbm_format = GBM_FORMAT_ARGB8888;
 	renderer->wlr_rend = create_renderer_func(&renderer->egl,
 		EGL_PLATFORM_GBM_MESA, renderer->gbm,
-		config_attribs, GBM_FORMAT_ARGB8888);
-
+		config_attribs, renderer->gbm_format);
 	if (!renderer->wlr_rend) {
 		wlr_log(WLR_ERROR, "Failed to create EGL/WLR renderer");
 		goto error_gbm;
@@ -234,7 +230,7 @@ struct gbm_bo *copy_drm_surface_mgpu(struct wlr_drm_surface *dest,
 
 	struct wlr_renderer *renderer = dest->renderer->wlr_rend;
 	wlr_renderer_begin(renderer, dest->width, dest->height);
-	wlr_renderer_clear(renderer, (float[]){ 0.0, 0.0, 0.0, 1.0 });
+	wlr_renderer_clear(renderer, (float[]){ 0.0, 0.0, 0.0, 0.0 });
 	wlr_render_texture_with_matrix(renderer, tex, mat, 1.0f);
 	wlr_renderer_end(renderer);