diff --git a/drivers/gpu/drm/tiny/simpledrm.c b/drivers/gpu/drm/tiny/simpledrm.c
index 7c7d0aca8e31e4e09ed849142371481dab1ebd0c..2f999915b9aad0c4097ee69deffb78d9ced84404 100644
--- a/drivers/gpu/drm/tiny/simpledrm.c
+++ b/drivers/gpu/drm/tiny/simpledrm.c
@@ -2,6 +2,7 @@
 
 #include <linux/clk.h>
 #include <linux/of_clk.h>
+#include <linux/minmax.h>
 #include <linux/platform_data/simplefb.h>
 #include <linux/platform_device.h>
 #include <linux/regulator/consumer.h>
@@ -772,6 +773,7 @@ static int simpledrm_device_init_modeset(struct simpledrm_device *sdev)
 	struct drm_display_mode *mode = &sdev->mode;
 	struct drm_connector *connector = &sdev->connector;
 	struct drm_simple_display_pipe *pipe = &sdev->pipe;
+	unsigned long max_width, max_height;
 	const uint32_t *formats;
 	size_t nformats;
 	int ret;
@@ -780,10 +782,13 @@ static int simpledrm_device_init_modeset(struct simpledrm_device *sdev)
 	if (ret)
 		return ret;
 
+	max_width = max_t(unsigned long, mode->hdisplay, DRM_SHADOW_PLANE_MAX_WIDTH);
+	max_height = max_t(unsigned long, mode->vdisplay, DRM_SHADOW_PLANE_MAX_HEIGHT);
+
 	dev->mode_config.min_width = mode->hdisplay;
-	dev->mode_config.max_width = mode->hdisplay;
+	dev->mode_config.max_width = max_width;
 	dev->mode_config.min_height = mode->vdisplay;
-	dev->mode_config.max_height = mode->vdisplay;
+	dev->mode_config.max_height = max_height;
 	dev->mode_config.prefer_shadow_fbdev = true;
 	dev->mode_config.preferred_depth = sdev->format->cpp[0] * 8;
 	dev->mode_config.funcs = &simpledrm_mode_config_funcs;
diff --git a/include/drm/drm_gem_atomic_helper.h b/include/drm/drm_gem_atomic_helper.h
index 48222a107873725fbd84c785aeed057d38259429..0b1e2dd2ac3ffd92decc9fe540f62a23dfaa27ee 100644
--- a/include/drm/drm_gem_atomic_helper.h
+++ b/include/drm/drm_gem_atomic_helper.h
@@ -22,6 +22,24 @@ int drm_gem_simple_display_pipe_prepare_fb(struct drm_simple_display_pipe *pipe,
  * Helpers for planes with shadow buffers
  */
 
+/**
+ * DRM_SHADOW_PLANE_MAX_WIDTH - Maximum width of a plane's shadow buffer in pixels
+ *
+ * For drivers with shadow planes, the maximum width of the framebuffer is
+ * usually independent from hardware limitations. Drivers can initialize struct
+ * drm_mode_config.max_width from DRM_SHADOW_PLANE_MAX_WIDTH.
+ */
+#define DRM_SHADOW_PLANE_MAX_WIDTH	(4096u)
+
+/**
+ * DRM_SHADOW_PLANE_MAX_HEIGHT - Maximum height of a plane's shadow buffer in scanlines
+ *
+ * For drivers with shadow planes, the maximum height of the framebuffer is
+ * usually independent from hardware limitations. Drivers can initialize struct
+ * drm_mode_config.max_height from DRM_SHADOW_PLANE_MAX_HEIGHT.
+ */
+#define DRM_SHADOW_PLANE_MAX_HEIGHT	(4096u)
+
 /**
  * struct drm_shadow_plane_state - plane state for planes with shadow buffers
  *