drm/qxl: track primary bo

Track which bo is used as primary surface.  With that in place we don't
need the primary_created flag any more, we can just check the primary bo
pointer instead.

Also verify we don't already have a primary surface in
qxl_io_create_primary().
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Noralf Trønnes <noralf@tronnes.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20190118122020.27596-13-kraxel@redhat.com

drivers/gpu/drm/qxl/qxl_cmd.c

@@ -374,13 +374,16 @@ void qxl_io_flush_surfaces(struct qxl_device *qdev)
 void qxl_io_destroy_primary(struct qxl_device *qdev)
 {
 	wait_for_io_cmd(qdev, 0, QXL_IO_DESTROY_PRIMARY_ASYNC);
-	qdev->primary_created = false;
+	qdev->primary_bo = NULL;
 }
 
 void qxl_io_create_primary(struct qxl_device *qdev, struct qxl_bo *bo)
 {
 	struct qxl_surface_create *create;
 
+	if (WARN_ON(qdev->primary_bo))
+		return;
+
 	DRM_DEBUG_DRIVER("qdev %p, ram_header %p\n", qdev, qdev->ram_header);
 	create = &qdev->ram_header->create_surface;
 	create->format = bo->surf.format;
@@ -399,7 +402,7 @@ void qxl_io_create_primary(struct qxl_device *qdev, struct qxl_bo *bo)
 	create->type = QXL_SURF_TYPE_PRIMARY;
 
 	wait_for_io_cmd(qdev, 0, QXL_IO_CREATE_PRIMARY_ASYNC);
-	qdev->primary_created = true;
+	qdev->primary_bo = bo;
 }
 
 void qxl_io_memslot_add(struct qxl_device *qdev, uint8_t id)

drivers/gpu/drm/qxl/qxl_display.c

@@ -302,7 +302,7 @@ static void qxl_crtc_update_monitors_config(struct drm_crtc *crtc,
 	struct qxl_head head;
 	int oldcount, i = qcrtc->index;
 
-	if (!qdev->primary_created) {
+	if (!qdev->primary_bo) {
 		DRM_DEBUG_KMS("no primary surface, skip (%s)\n", reason);
 		return;
 	}

drivers/gpu/drm/qxl/qxl_drv.h

@@ -229,7 +229,7 @@ struct qxl_device {
 
 	struct qxl_ram_header *ram_header;
 
-	unsigned int primary_created:1;
+	struct qxl_bo *primary_bo;
 
 	struct qxl_memslot main_slot;
 	struct qxl_memslot surfaces_slot;