3 files changed, 30 insertions, 12 deletions

diff --git a/Documentation/video4linux/v4l2-controls.txt b/Documentation/video4linux/v4l2-controls.txt
index 8773778d23fc..881e7f44491b 100644
--- a/Documentation/video4linux/v4l2-controls.txt
+++ b/Documentation/video4linux/v4l2-controls.txt
@@ -285,6 +285,9 @@ implement g_volatile_ctrl like this:
 The 'new value' union is not used in g_volatile_ctrl. In general controls
 that need to implement g_volatile_ctrl are read-only controls.
 
+Note that if one or more controls in a control cluster are marked as volatile,
+then all the controls in the cluster are seen as volatile.
+
 To mark a control as volatile you have to set the is_volatile flag:
 
         ctrl = v4l2_ctrl_new_std(&sd->ctrl_handler, ...);
@@ -462,6 +465,15 @@ pointer to the v4l2_ctrl_ops struct that is used for that cluster.
 Obviously, all controls in the cluster array must be initialized to either
 a valid control or to NULL.
 
+In rare cases you might want to know which controls of a cluster actually
+were set explicitly by the user. For this you can check the 'is_new' flag of
+each control. For example, in the case of a volume/mute cluster the 'is_new'
+flag of the mute control would be set if the user called VIDIOC_S_CTRL for
+mute only. If the user would call VIDIOC_S_EXT_CTRLS for both mute and volume
+controls, then the 'is_new' flag would be 1 for both controls.
+
+The 'is_new' flag is always 1 when called from v4l2_ctrl_handler_setup().
+
 
 VIDIOC_LOG_STATUS Support
 =========================
diff --git a/drivers/media/video/v4l2-ctrls.c b/drivers/media/video/v4l2-ctrls.c
index 8f81efcfcf56..0d1a3d831374 100644
--- a/drivers/media/video/v4l2-ctrls.c
+++ b/drivers/media/video/v4l2-ctrls.c
@@ -569,7 +569,7 @@ static int user_to_new(struct v4l2_ext_control *c,
         int ret;
         u32 size;
 
-        ctrl->has_new = 1;
+        ctrl->is_new = 1;
         switch (ctrl->type) {
         case V4L2_CTRL_TYPE_INTEGER64:
                 ctrl->val64 = c->value64;
@@ -1280,8 +1280,12 @@ int v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl)
                 if (ctrl->done)
                         continue;
 
-                for (i = 0; i < master->ncontrols; i++)
-                        cur_to_new(master->cluster[i]);
+                for (i = 0; i < master->ncontrols; i++) {
+                        if (master->cluster[i]) {
+                                cur_to_new(master->cluster[i]);
+                                master->cluster[i]->is_new = 1;
+                        }
+                }
 
                 /* Skip button controls and read-only controls. */
                 if (ctrl->type == V4L2_CTRL_TYPE_BUTTON ||
@@ -1645,7 +1649,7 @@ static int try_or_set_control_cluster(struct v4l2_ctrl *master, bool set)
                 if (ctrl == NULL)
                         continue;
 
-                if (ctrl->has_new) {
+                if (ctrl->is_new) {
                         /* Double check this: it may have changed since the
                            last check in try_or_set_ext_ctrls(). */
                         if (set && (ctrl->flags & V4L2_CTRL_FLAG_GRABBED))
@@ -1719,13 +1723,13 @@ static int try_or_set_ext_ctrls(struct v4l2_ctrl_handler *hdl,
 
                 v4l2_ctrl_lock(ctrl);
 
-                /* Reset the 'has_new' flags of the cluster */
+                /* Reset the 'is_new' flags of the cluster */
                 for (j = 0; j < master->ncontrols; j++)
                         if (master->cluster[j])
-                                master->cluster[j]->has_new = 0;
+                                master->cluster[j]->is_new = 0;
 
                 /* Copy the new caller-supplied control values.
-                   user_to_new() sets 'has_new' to 1. */
+                   user_to_new() sets 'is_new' to 1. */
                 ret = cluster_walk(i, cs, helpers, user_to_new);
 
                 if (!ret)
@@ -1822,13 +1826,13 @@ static int set_ctrl(struct v4l2_ctrl *ctrl, s32 *val)
 
         v4l2_ctrl_lock(ctrl);
 
-        /* Reset the 'has_new' flags of the cluster */
+        /* Reset the 'is_new' flags of the cluster */
         for (i = 0; i < master->ncontrols; i++)
                 if (master->cluster[i])
-                        master->cluster[i]->has_new = 0;
+                        master->cluster[i]->is_new = 0;
 
         ctrl->val = *val;
-        ctrl->has_new = 1;
+        ctrl->is_new = 1;
         ret = try_or_set_control_cluster(master, false);
         if (!ret)
                 ret = try_or_set_control_cluster(master, true);
diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
index d69ab4aae032..fcc9a0cf8ff1 100644
--- a/include/media/v4l2-ctrls.h
+++ b/include/media/v4l2-ctrls.h
@@ -53,8 +53,10 @@ struct v4l2_ctrl_ops {
   * @handler:   The handler that owns the control.
   * @cluster:   Point to start of cluster array.
   * @ncontrols: Number of controls in cluster array.
-  * @has_new:   Internal flag: set when there is a valid new value.
   * @done:      Internal flag: set for each processed control.
+  * @is_new:    Set when the user specified a new value for this control. It
+  *             is also set when called from v4l2_ctrl_handler_setup. Drivers
+  *             should never set this flag.
   * @is_private: If set, then this control is private to its handler and it
   *             will not be added to any other handlers. Drivers can set
   *             this flag.
@@ -97,9 +99,9 @@ struct v4l2_ctrl {
         struct v4l2_ctrl_handler *handler;
         struct v4l2_ctrl **cluster;
         unsigned ncontrols;
-        unsigned int has_new:1;
         unsigned int done:1;
 
+        unsigned int is_new:1;
         unsigned int is_private:1;
         unsigned int is_volatile:1;