[PATCH] drm/damage_helper: Check if damage clips has valid values

[Souza, Jose]

On Sun, 2020-12-13 at 17:22 +0000, Simon Ser wrote:
> Can you add some drm_dbg_atomic logs when the damage is invalid, to make it
> easier for user-space to understand why an atomic commit failed?

sure, this is enough? will wait for a couple of more days before send another version.


diff --git a/drivers/gpu/drm/drm_damage_helper.c b/drivers/gpu/drm/drm_damage_helper.c
index 9adb369440ba..b598b137d27f 100644
--- a/drivers/gpu/drm/drm_damage_helper.c
+++ b/drivers/gpu/drm/drm_damage_helper.c
@@ -33,6 +33,7 @@
 #include <drm/drm_atomic.h>
 #include <drm/drm_damage_helper.h>
 #include <drm/drm_device.h>
+#include <drm/drm_print.h>

 /**
  * DOC: overview
@@ -152,16 +153,25 @@ int drm_atomic_helper_check_plane_damage(struct drm_atomic_state *state,

        for (; num_clips; num_clips--, damaged_clips++) {
                if (damaged_clips->x1 < 0 || damaged_clips->x2 < 0 ||
-                   damaged_clips->y1 < 0 || damaged_clips->y2 < 0)
+                   damaged_clips->y1 < 0 || damaged_clips->y2 < 0) {
+                       drm_dbg_atomic(state->dev,
+                                      "Invalid damage clip, negative coordinate\n");
                        return -EINVAL;
+               }

                if (damaged_clips->x2 < damaged_clips->x1 ||
-                   damaged_clips->y2 < damaged_clips->y1)
+                   damaged_clips->y2 < damaged_clips->y1) {
+                       drm_dbg_atomic(state->dev,
+                                      "Invalid damage clip, negative width or height\n");
                        return -EINVAL;
+               }

                if ((damaged_clips->x2 - damaged_clips->x1) > w ||
-                   (damaged_clips->y2 - damaged_clips->y1) > h)
+                   (damaged_clips->y2 - damaged_clips->y1) > h) {
+                       drm_dbg_atomic(state->dev,
+                                      "Invalid damage clip, width or height larger than plane\n");
                        return -EINVAL;
+               }
        }

        return 0;