2 files changed, 50 insertions, 7 deletions

diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index dfc8ca1e9413..9b9ba5d5ec0c 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -1531,8 +1531,10 @@ static struct drm_encoder *drm_connector_get_encoder(struct drm_connector *conne
         return connector->encoder;
 }
 
-static bool drm_mode_expose_to_userspace(const struct drm_display_mode *mode,
-                                         const struct drm_file *file_priv)
+static bool
+drm_mode_expose_to_userspace(const struct drm_display_mode *mode,
+                             const struct list_head *export_list,
+                             const struct drm_file *file_priv)
 {
         /*
          * If user-space hasn't configured the driver to expose the stereo 3D
@@ -1540,6 +1542,23 @@ static bool drm_mode_expose_to_userspace(const struct drm_display_mode *mode,
          */
         if (!file_priv->stereo_allowed && drm_mode_is_stereo(mode))
                 return false;
+        /*
+         * If user-space hasn't configured the driver to expose the modes
+         * with aspect-ratio, don't expose them. However if such a mode
+         * is unique, let it be exposed, but reset the aspect-ratio flags
+         * while preparing the list of user-modes.
+         */
+        if (!file_priv->aspect_ratio_allowed) {
+                struct drm_display_mode *mode_itr;
+
+                list_for_each_entry(mode_itr, export_list, export_head)
+                        if (drm_mode_match(mode_itr, mode,
+                                           DRM_MODE_MATCH_TIMINGS |
+                                           DRM_MODE_MATCH_CLOCK |
+                                           DRM_MODE_MATCH_FLAGS |
+                                           DRM_MODE_MATCH_3D_FLAGS))
+                                return false;
+        }
 
         return true;
 }
@@ -1559,6 +1578,7 @@ int drm_mode_getconnector(struct drm_device *dev, void *data,
         struct drm_mode_modeinfo u_mode;
         struct drm_mode_modeinfo __user *mode_ptr;
         uint32_t __user *encoder_ptr;
+        LIST_HEAD(export_list);
 
         if (!drm_core_check_feature(dev, DRIVER_MODESET))
                 return -EINVAL;
@@ -1607,21 +1627,31 @@ int drm_mode_getconnector(struct drm_device *dev, void *data,
 
         /* delayed so we get modes regardless of pre-fill_modes state */
         list_for_each_entry(mode, &connector->modes, head)
-                if (drm_mode_expose_to_userspace(mode, file_priv))
+                if (drm_mode_expose_to_userspace(mode, &export_list,
+                                                 file_priv)) {
+                        list_add_tail(&mode->export_head, &export_list);
                         mode_count++;
+                }
 
         /*
          * This ioctl is called twice, once to determine how much space is
          * needed, and the 2nd time to fill it.
+         * The modes that need to be exposed to the user are maintained in the
+         * 'export_list'. When the ioctl is called first time to determine the,
+         * space, the export_list gets filled, to find the no.of modes. In the
+         * 2nd time, the user modes are filled, one by one from the export_list.
          */
         if ((out_resp->count_modes >= mode_count) && mode_count) {
                 copied = 0;
                 mode_ptr = (struct drm_mode_modeinfo __user *)(unsigned long)out_resp->modes_ptr;
-                list_for_each_entry(mode, &connector->modes, head) {
-                        if (!drm_mode_expose_to_userspace(mode, file_priv))
-                                continue;
-
+                list_for_each_entry(mode, &export_list, export_head) {
                         drm_mode_convert_to_umode(&u_mode, mode);
+                        /*
+                         * Reset aspect ratio flags of user-mode, if modes with
+                         * aspect-ratio are not supported.
+                         */
+                        if (!file_priv->aspect_ratio_allowed)
+                                u_mode.flags &= ~DRM_MODE_FLAG_PIC_AR_MASK;
                         if (copy_to_user(mode_ptr + copied,
                                          &u_mode, sizeof(u_mode))) {
                                 ret = -EFAULT;
diff --git a/include/drm/drm_modes.h b/include/drm/drm_modes.h
index 2f78b7ee4824..b159fe07fcf9 100644
--- a/include/drm/drm_modes.h
+++ b/include/drm/drm_modes.h
@@ -411,6 +411,19 @@ struct drm_display_mode {
          * Field for setting the HDMI picture aspect ratio of a mode.
          */
         enum hdmi_picture_aspect picture_aspect_ratio;
+
+        /**
+         * @export_head:
+         *
+         * struct list_head for modes to be exposed to the userspace.
+         * This is to maintain a list of exposed modes while preparing
+         * user-mode's list in drm_mode_getconnector ioctl. The purpose of this
+         * list_head only lies in the ioctl function, and is not expected to be
+         * used outside the function.
+         * Once used, the stale pointers are not reset, but left as it is, to
+         * avoid overhead of protecting it by mode_config.mutex.
+         */
+        struct list_head export_head;
 };
 
 /**