drm/fb-helper: Remove struct drm_fb_helper.fb_probe

The callback fb_probe in struct drm_fb_helper is unused. Remove it.
New drivers should set struct drm_driver.fbdev_probe instead and call
drm_client_setup() to instantiate in-kernel DRM clients.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241212170913.185939-13-tzimmermann@suse.de
Signed-off-by: Maarten Lankhorst <dev@lankhorst.se>

Author: tdz

drivers/gpu/drm/drm_fb_helper.c

@@ -1634,6 +1634,9 @@ static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper)
 	struct fb_info *info;
 	int ret;
 
+	if (drm_WARN_ON(dev, !dev->driver->fbdev_probe))
+		return -EINVAL;
+
 	ret = drm_fb_helper_find_sizes(fb_helper, &sizes);
 	if (ret) {
 		/* First time: disable all crtc's.. */
@@ -1643,10 +1646,7 @@ static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper)
 	}
 
 	/* push down into drivers */
-	if (dev->driver->fbdev_probe)
-		ret = dev->driver->fbdev_probe(fb_helper, &sizes);
-	else if (fb_helper->funcs)
-		ret = fb_helper->funcs->fb_probe(fb_helper, &sizes);
+	ret = dev->driver->fbdev_probe(fb_helper, &sizes);
 	if (ret < 0)
 		return ret;
 

include/drm/drm_fb_helper.h

@@ -69,23 +69,6 @@ struct drm_fb_helper_surface_size {
  * Driver callbacks used by the fbdev emulation helper library.
  */
 struct drm_fb_helper_funcs {
-	/**
-	 * @fb_probe:
-	 *
-	 * Driver callback to allocate and initialize the fbdev info structure.
-	 * Furthermore it also needs to allocate the DRM framebuffer used to
-	 * back the fbdev.
-	 *
-	 * This callback is mandatory.
-	 *
-	 * RETURNS:
-	 *
-	 * The driver should return 0 on success and a negative error code on
-	 * failure.
-	 */
-	int (*fb_probe)(struct drm_fb_helper *helper,
-			struct drm_fb_helper_surface_size *sizes);
-
 	/**
 	 * @fb_dirty:
 	 *