drm: exynos: fix for loosing display mode header during mode adjustment

This patch is to preserve the display mode header during the mode adjustment.
Display mode header is overwritten with the adjusted mode header which is
throwing the stack dump.

Signed-off-by: Rahul Sharma <rahul.sharma@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
diff --git a/drivers/gpu/drm/exynos/exynos_hdmi.c b/drivers/gpu/drm/exynos/exynos_hdmi.c
index 6716ecd..a405227 100644
--- a/drivers/gpu/drm/exynos/exynos_hdmi.c
+++ b/drivers/gpu/drm/exynos/exynos_hdmi.c
@@ -1979,9 +1979,18 @@
 			index = hdmi_v14_conf_index(m);
 
 		if (index >= 0) {
+			struct drm_mode_object base;
+			struct list_head head;
+
 			DRM_INFO("desired mode doesn't exist so\n");
 			DRM_INFO("use the most suitable mode among modes.\n");
+
+			/* preserve display mode header while copying. */
+			head = adjusted_mode->head;
+			base = adjusted_mode->base;
 			memcpy(adjusted_mode, m, sizeof(*m));
+			adjusted_mode->head = head;
+			adjusted_mode->base = base;
 			break;
 		}
 	}