linux-dmabuf: send deprecated format events

Although the format event is deprecated, some clients, especially the
GStreamer waylandsink, only support zwp_linux_dmabuf_v1 version 1 and
require the deprecated format event.

Send format events instead of the modifier event, if the client binds on
a protocol version before version 3, skipping formats that only support
non-linear modifiers.

Signed-off-by: Michael Tretter <m.tretter@pengutronix.de>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Daniel Stone <daniels@collabora.com>

libweston/linux-dmabuf.c

@@ -488,8 +488,6 @@ bind_linux_dmabuf(struct wl_client *client,
 	wl_resource_set_implementation(resource, &linux_dmabuf_implementation,
 				       compositor, NULL);
 
-	if (version < ZWP_LINUX_DMABUF_V1_MODIFIER_SINCE_VERSION)
-		return;
 	/*
 	 * Use EGL_EXT_image_dma_buf_import_modifiers to query and advertise
 	 * format/modifier codes.
@@ -510,11 +508,18 @@ bind_linux_dmabuf(struct wl_client *client,
 			modifiers = &modifier_invalid;
 		}
 		for (j = 0; j < num_modifiers; j++) {
+			if (version >= ZWP_LINUX_DMABUF_V1_MODIFIER_SINCE_VERSION) {
 				uint32_t modifier_lo = modifiers[j] & 0xFFFFFFFF;
 				uint32_t modifier_hi = modifiers[j] >> 32;
-			zwp_linux_dmabuf_v1_send_modifier(resource, formats[i],
+				zwp_linux_dmabuf_v1_send_modifier(resource,
+								  formats[i],
 								  modifier_hi,
 								  modifier_lo);
+			} else if (modifiers[j] == DRM_FORMAT_MOD_LINEAR ||
+				   modifiers == &modifier_invalid) {
+				zwp_linux_dmabuf_v1_send_format(resource,
+								formats[i]);
+			}
 		}
 		if (modifiers != &modifier_invalid)
 			free(modifiers);

libweston/linux-dmabuf.h

@@ -32,6 +32,9 @@
 #ifndef DRM_FORMAT_MOD_INVALID
 #define DRM_FORMAT_MOD_INVALID ((1ULL<<56) - 1)
 #endif
+#ifndef DRM_FORMAT_MOD_LINEAR
+#define DRM_FORMAT_MOD_LINEAR 0
+#endif
 
 struct linux_dmabuf_buffer;
 typedef void (*dmabuf_user_data_destroy_func)(