drm: check edid data, so we deal well with broken driver.

diff --git a/linux-core/drm_edid.c b/linux-core/drm_edid.c
index b8eee1a..7068cef 100644 (file)
--- a/linux-core/drm_edid.c
+++ b/linux-core/drm_edid.c
@@ -469,6 +469,14 @@ int drm_add_edid_modes(struct drm_output *output, struct edid *edid)
 {
        int num_modes = 0;
 
+       if (edid == NULL) {
+               return 0;
+       }
+       if (!edid_valid(edid)) {
+               dev_warn(&output->dev->pdev->dev, "%s: EDID invalid.\n",
+                        output->name);
+               return 0;
+       }
        num_modes += add_established_modes(output, edid);
        num_modes += add_standard_modes(output, edid);
        num_modes += add_detailed_info(output, edid);