Add fb_blank function pointer to struct fb_ops and enable paths that

set it.  Also add fb_blank() which uses it, for use in inteldrm(4).

sys/dev/pci/drm/i915/display/intel_fbdev.c

@@ -164,8 +164,8 @@ static const struct fb_ops intelfb_ops = {
 	DRM_FB_HELPER_DEFAULT_OPS,
 #endif
 	.fb_set_par = intel_fbdev_set_par,
-#ifdef notyet
 	.fb_blank = intel_fbdev_blank,
+#ifdef notyet
 	.fb_pan_display = intel_fbdev_pan_display,
 	__FB_DEFAULT_DEFERRED_OPS_DRAW(intel_fbdev),
 	.fb_mmap = intel_fbdev_mmap,

sys/dev/pci/drm/include/drm/drm_fb_helper.h

@@ -242,7 +242,8 @@ drm_fb_helper_from_client(struct drm_client_dev *client)
 	.fb_ioctl	= drm_fb_helper_ioctl
 #else
 #define DRM_FB_HELPER_DEFAULT_OPS \
-	.fb_set_par	= drm_fb_helper_set_par
+	.fb_set_par	= drm_fb_helper_set_par, \
+	.fb_blank	= drm_fb_helper_blank
 #endif
 
 #ifdef CONFIG_DRM_FBDEV_EMULATION

sys/dev/pci/drm/include/linux/fb.h

@@ -29,6 +29,7 @@ struct fb_var_screeninfo {
 
 struct fb_ops {
 	int (*fb_set_par)(struct fb_info *);
+	int (*fb_blank)(int, struct fb_info *);
 };
 
 struct fb_fix_screeninfo {
@@ -97,6 +98,15 @@ fb_get_options(const char *name, char **opt)
 	return 0;
 }
 
+static inline int
+fb_blank(struct fb_info *fbi, int b)
+{
+	int r = 0;
+	if (fbi->fbops && fbi->fbops->fb_blank)
+		r = fbi->fbops->fb_blank(b, fbi);
+	return r;
+}
+
 static inline int
 register_framebuffer(struct fb_info *fbi)
 {