[media] v4l2-ctrls: v4l2_ctrl_handler_setup code simplification
[pandora-kernel.git] / drivers / media / video / v4l2-ctrls.c
index 5f31666..cc2b589 100644 (file)
        (has_op(master, op) ? master->ops->op(master) : 0)
 
 /* Internal temporary helper struct, one for each v4l2_ext_control */
-struct ctrl_helper {
+struct v4l2_ctrl_helper {
+       /* Pointer to the control reference of the master control */
+       struct v4l2_ctrl_ref *mref;
        /* The control corresponding to the v4l2_ext_control ID field. */
        struct v4l2_ctrl *ctrl;
-       /* Used internally to mark whether this control was already
-          processed. */
-       bool handled;
+       /* v4l2_ext_control index of the next control belonging to the
+          same cluster, or 0 if there isn't any. */
+       u32 next;
 };
 
 /* Small helper function to determine if the autocluster is set to manual
@@ -581,15 +583,15 @@ static void fill_event(struct v4l2_event *ev, struct v4l2_ctrl *ctrl, u32 change
 static void send_event(struct v4l2_fh *fh, struct v4l2_ctrl *ctrl, u32 changes)
 {
        struct v4l2_event ev;
-       struct v4l2_ctrl_fh *pos;
+       struct v4l2_subscribed_event *sev;
 
-       if (list_empty(&ctrl->fhs))
+       if (list_empty(&ctrl->ev_subs))
                        return;
        fill_event(&ev, ctrl, changes);
 
-       list_for_each_entry(pos, &ctrl->fhs, node)
-               if (pos->fh != fh)
-                       v4l2_event_queue_fh(pos->fh, &ev);
+       list_for_each_entry(sev, &ctrl->ev_subs, node)
+               if (sev->fh && sev->fh != fh)
+                       v4l2_event_queue_fh(sev->fh, &ev);
 }
 
 /* Helper function: copy the current control value back to the caller */
@@ -678,20 +680,6 @@ static int new_to_user(struct v4l2_ext_control *c,
        return 0;
 }
 
-static int ctrl_to_user(struct v4l2_ext_control *c,
-                      struct v4l2_ctrl *ctrl)
-{
-       if (ctrl->is_volatile)
-               return new_to_user(c, ctrl);
-       return cur_to_user(c, ctrl);
-}
-
-static int ctrl_is_volatile(struct v4l2_ext_control *c,
-                      struct v4l2_ctrl *ctrl)
-{
-       return ctrl->is_volatile;
-}
-
 /* Copy the new value to the current value. */
 static void new_to_cur(struct v4l2_fh *fh, struct v4l2_ctrl *ctrl,
                                                bool update_inactive)
@@ -779,13 +767,11 @@ static int cluster_changed(struct v4l2_ctrl *master)
        return diff;
 }
 
-/* Validate a new control */
-static int validate_new(struct v4l2_ctrl *ctrl)
+/* Validate integer-type control */
+static int validate_new_int(const struct v4l2_ctrl *ctrl, s32 *pval)
 {
-       s32 val = ctrl->val;
-       char *s = ctrl->string;
+       s32 val = *pval;
        u32 offset;
-       size_t len;
 
        switch (ctrl->type) {
        case V4L2_CTRL_TYPE_INTEGER:
@@ -798,11 +784,11 @@ static int validate_new(struct v4l2_ctrl *ctrl)
                offset = val - ctrl->minimum;
                offset = ctrl->step * (offset / ctrl->step);
                val = ctrl->minimum + offset;
-               ctrl->val = val;
+               *pval = val;
                return 0;
 
        case V4L2_CTRL_TYPE_BOOLEAN:
-               ctrl->val = !!ctrl->val;
+               *pval = !!val;
                return 0;
 
        case V4L2_CTRL_TYPE_MENU:
@@ -815,9 +801,28 @@ static int validate_new(struct v4l2_ctrl *ctrl)
 
        case V4L2_CTRL_TYPE_BUTTON:
        case V4L2_CTRL_TYPE_CTRL_CLASS:
-               ctrl->val64 = 0;
+               *pval = 0;
                return 0;
 
+       default:
+               return -EINVAL;
+       }
+}
+
+/* Validate a new control */
+static int validate_new(const struct v4l2_ctrl *ctrl, struct v4l2_ext_control *c)
+{
+       char *s = c->string;
+       size_t len;
+
+       switch (ctrl->type) {
+       case V4L2_CTRL_TYPE_INTEGER:
+       case V4L2_CTRL_TYPE_BOOLEAN:
+       case V4L2_CTRL_TYPE_MENU:
+       case V4L2_CTRL_TYPE_BUTTON:
+       case V4L2_CTRL_TYPE_CTRL_CLASS:
+               return validate_new_int(ctrl, &c->value);
+
        case V4L2_CTRL_TYPE_INTEGER64:
                return 0;
 
@@ -867,7 +872,7 @@ void v4l2_ctrl_handler_free(struct v4l2_ctrl_handler *hdl)
 {
        struct v4l2_ctrl_ref *ref, *next_ref;
        struct v4l2_ctrl *ctrl, *next_ctrl;
-       struct v4l2_ctrl_fh *ctrl_fh, *next_ctrl_fh;
+       struct v4l2_subscribed_event *sev, *next_sev;
 
        if (hdl == NULL || hdl->buckets == NULL)
                return;
@@ -881,10 +886,8 @@ void v4l2_ctrl_handler_free(struct v4l2_ctrl_handler *hdl)
        /* Free all controls owned by the handler */
        list_for_each_entry_safe(ctrl, next_ctrl, &hdl->ctrls, node) {
                list_del(&ctrl->node);
-               list_for_each_entry_safe(ctrl_fh, next_ctrl_fh, &ctrl->fhs, node) {
-                       list_del(&ctrl_fh->node);
-                       kfree(ctrl_fh);
-               }
+               list_for_each_entry_safe(sev, next_sev, &ctrl->ev_subs, node)
+                       list_del(&sev->node);
                kfree(ctrl);
        }
        kfree(hdl->buckets);
@@ -1083,7 +1086,7 @@ static struct v4l2_ctrl *v4l2_ctrl_new(struct v4l2_ctrl_handler *hdl,
        }
 
        INIT_LIST_HEAD(&ctrl->node);
-       INIT_LIST_HEAD(&ctrl->fhs);
+       INIT_LIST_HEAD(&ctrl->ev_subs);
        ctrl->handler = hdl;
        ctrl->ops = ops;
        ctrl->id = id;
@@ -1263,6 +1266,7 @@ void v4l2_ctrl_auto_cluster(unsigned ncontrols, struct v4l2_ctrl **controls,
 
        v4l2_ctrl_cluster(ncontrols, controls);
        WARN_ON(ncontrols <= 1);
+       WARN_ON(manual_val < master->minimum || manual_val > master->maximum);
        master->is_auto = true;
        master->manual_mode_value = manual_val;
        master->flags |= V4L2_CTRL_FLAG_UPDATE;
@@ -1407,26 +1411,21 @@ int v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl)
                int i;
 
                /* Skip if this control was already handled by a cluster. */
-               if (ctrl->done)
+               /* Skip button controls and read-only controls. */
+               if (ctrl->done || ctrl->type == V4L2_CTRL_TYPE_BUTTON ||
+                   (ctrl->flags & V4L2_CTRL_FLAG_READ_ONLY))
                        continue;
 
                for (i = 0; i < master->ncontrols; i++) {
                        if (master->cluster[i]) {
                                cur_to_new(master->cluster[i]);
                                master->cluster[i]->is_new = 1;
+                               master->cluster[i]->done = true;
                        }
                }
-
-               /* Skip button controls and read-only controls. */
-               if (ctrl->type == V4L2_CTRL_TYPE_BUTTON ||
-                   (ctrl->flags & V4L2_CTRL_FLAG_READ_ONLY))
-                       continue;
                ret = call_op(master, s_ctrl);
                if (ret)
                        break;
-               for (i = 0; i < master->ncontrols; i++)
-                       if (master->cluster[i])
-                               master->cluster[i]->done = true;
        }
        mutex_unlock(&hdl->lock);
        return ret;
@@ -1577,12 +1576,15 @@ EXPORT_SYMBOL(v4l2_subdev_querymenu);
    Find the controls in the control array and do some basic checks. */
 static int prepare_ext_ctrls(struct v4l2_ctrl_handler *hdl,
                             struct v4l2_ext_controls *cs,
-                            struct ctrl_helper *helpers)
+                            struct v4l2_ctrl_helper *helpers)
 {
+       struct v4l2_ctrl_helper *h;
+       bool have_clusters = false;
        u32 i;
 
-       for (i = 0; i < cs->count; i++) {
+       for (i = 0, h = helpers; i < cs->count; i++, h++) {
                struct v4l2_ext_control *c = &cs->controls[i];
+               struct v4l2_ctrl_ref *ref;
                struct v4l2_ctrl *ctrl;
                u32 id = c->id & V4L2_CTRL_ID_MASK;
 
@@ -1595,53 +1597,59 @@ static int prepare_ext_ctrls(struct v4l2_ctrl_handler *hdl,
                   extended controls */
                if (id >= V4L2_CID_PRIVATE_BASE)
                        return -EINVAL;
-               ctrl = v4l2_ctrl_find(hdl, id);
-               if (ctrl == NULL)
+               ref = find_ref_lock(hdl, id);
+               if (ref == NULL)
                        return -EINVAL;
+               ctrl = ref->ctrl;
                if (ctrl->flags & V4L2_CTRL_FLAG_DISABLED)
                        return -EINVAL;
 
-               helpers[i].ctrl = ctrl;
-               helpers[i].handled = false;
+               if (ctrl->cluster[0]->ncontrols > 1)
+                       have_clusters = true;
+               if (ctrl->cluster[0] != ctrl)
+                       ref = find_ref_lock(hdl, ctrl->cluster[0]->id);
+               /* Store the ref to the master control of the cluster */
+               h->mref = ref;
+               h->ctrl = ctrl;
+               /* Initially set next to 0, meaning that there is no other
+                  control in this helper array belonging to the same
+                  cluster */
+               h->next = 0;
        }
-       return 0;
-}
 
-typedef int (*cluster_func)(struct v4l2_ext_control *c,
-                           struct v4l2_ctrl *ctrl);
+       /* We are done if there were no controls that belong to a multi-
+          control cluster. */
+       if (!have_clusters)
+               return 0;
 
-/* Walk over all controls in v4l2_ext_controls belonging to the same cluster
-   and call the provided function. */
-static int cluster_walk(unsigned from,
-                       struct v4l2_ext_controls *cs,
-                       struct ctrl_helper *helpers,
-                       cluster_func f)
-{
-       struct v4l2_ctrl **cluster = helpers[from].ctrl->cluster;
-       int ret = 0;
-       int i;
+       /* The code below figures out in O(n) time which controls in the list
+          belong to the same cluster. */
 
-       /* Find any controls from the same cluster and call the function */
-       for (i = from; !ret && i < cs->count; i++) {
-               struct v4l2_ctrl *ctrl = helpers[i].ctrl;
+       /* This has to be done with the handler lock taken. */
+       mutex_lock(&hdl->lock);
 
-               if (!helpers[i].handled && ctrl->cluster == cluster)
-                       ret = f(&cs->controls[i], ctrl);
+       /* First zero the helper field in the master control references */
+       for (i = 0; i < cs->count; i++)
+               helpers[i].mref->helper = 0;
+       for (i = 0, h = helpers; i < cs->count; i++, h++) {
+               struct v4l2_ctrl_ref *mref = h->mref;
+
+               /* If the mref->helper is set, then it points to an earlier
+                  helper that belongs to the same cluster. */
+               if (mref->helper) {
+                       /* Set the next field of mref->helper to the current
+                          index: this means that that earlier helper now
+                          points to the next helper in the same cluster. */
+                       mref->helper->next = i;
+                       /* mref should be set only for the first helper in the
+                          cluster, clear the others. */
+                       h->mref = NULL;
+               }
+               /* Point the mref helper to the current helper struct. */
+               mref->helper = h;
        }
-       return ret;
-}
-
-static void cluster_done(unsigned from,
-                        struct v4l2_ext_controls *cs,
-                        struct ctrl_helper *helpers)
-{
-       struct v4l2_ctrl **cluster = helpers[from].ctrl->cluster;
-       int i;
-
-       /* Find any controls from the same cluster and mark them as handled */
-       for (i = from; i < cs->count; i++)
-               if (helpers[i].ctrl->cluster == cluster)
-                       helpers[i].handled = true;
+       mutex_unlock(&hdl->lock);
+       return 0;
 }
 
 /* Handles the corner case where cs->count == 0. It checks whether the
@@ -1659,8 +1667,8 @@ static int class_check(struct v4l2_ctrl_handler *hdl, u32 ctrl_class)
 /* Get extended controls. Allocates the helpers array if needed. */
 int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *cs)
 {
-       struct ctrl_helper helper[4];
-       struct ctrl_helper *helpers = helper;
+       struct v4l2_ctrl_helper helper[4];
+       struct v4l2_ctrl_helper *helpers = helper;
        int ret;
        int i, j;
 
@@ -1687,37 +1695,38 @@ int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *cs
                        ret = -EACCES;
 
        for (i = 0; !ret && i < cs->count; i++) {
-               struct v4l2_ctrl *ctrl = helpers[i].ctrl;
-               struct v4l2_ctrl *master = ctrl->cluster[0];
-               bool has_volatiles;
+               int (*ctrl_to_user)(struct v4l2_ext_control *c,
+                                   struct v4l2_ctrl *ctrl) = cur_to_user;
+               struct v4l2_ctrl *master;
 
-               if (helpers[i].handled)
+               if (helpers[i].mref == NULL)
                        continue;
 
+               master = helpers[i].mref->ctrl;
                cs->error_idx = i;
 
-               /* Any volatile controls requested from this cluster? */
-               has_volatiles = ctrl->is_volatile;
-               if (!has_volatiles && has_op(master, g_volatile_ctrl) &&
-                               master->ncontrols > 1)
-                       has_volatiles = cluster_walk(i, cs, helpers,
-                                               ctrl_is_volatile);
-
                v4l2_ctrl_lock(master);
 
                /* g_volatile_ctrl will update the new control values */
-               if (has_volatiles && !is_cur_manual(master)) {
+               if (has_op(master, g_volatile_ctrl) && !is_cur_manual(master)) {
                        for (j = 0; j < master->ncontrols; j++)
                                cur_to_new(master->cluster[j]);
                        ret = call_op(master, g_volatile_ctrl);
+                       ctrl_to_user = new_to_user;
                }
                /* If OK, then copy the current (for non-volatile controls)
                   or the new (for volatile controls) control values to the
                   caller */
-               if (!ret)
-                       ret = cluster_walk(i, cs, helpers, ctrl_to_user);
+               if (!ret) {
+                       u32 idx = i;
+
+                       do {
+                               ret = ctrl_to_user(cs->controls + idx,
+                                                  helpers[idx].ctrl);
+                               idx = helpers[idx].next;
+                       } while (!ret && idx);
+               }
                v4l2_ctrl_unlock(master);
-               cluster_done(i, cs, helpers);
        }
 
        if (cs->count > ARRAY_SIZE(helper))
@@ -1787,72 +1796,57 @@ EXPORT_SYMBOL(v4l2_ctrl_g_ctrl);
 /* Core function that calls try/s_ctrl and ensures that the new value is
    copied to the current value on a set.
    Must be called with ctrl->handler->lock held. */
-static int try_or_set_control_cluster(struct v4l2_fh *fh,
-                                       struct v4l2_ctrl *master, bool set)
+static int try_or_set_cluster(struct v4l2_fh *fh,
+                             struct v4l2_ctrl *master, bool set)
 {
        bool update_flag;
-       bool try = !set;
-       int ret = 0;
+       int ret;
        int i;
 
        /* Go through the cluster and either validate the new value or
           (if no new value was set), copy the current value to the new
           value, ensuring a consistent view for the control ops when
           called. */
-       for (i = 0; !ret && i < master->ncontrols; i++) {
+       for (i = 0; i < master->ncontrols; i++) {
                struct v4l2_ctrl *ctrl = master->cluster[i];
 
                if (ctrl == NULL)
                        continue;
 
-               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))
-                               return -EBUSY;
-
-                       /* Validate if required */
-                       if (!set)
-                               ret = validate_new(ctrl);
+               if (!ctrl->is_new) {
+                       cur_to_new(ctrl);
                        continue;
                }
-               /* No new value was set, so copy the current and force
-                  a call to try_ctrl later, since the values for the cluster
-                  may now have changed and the end result might be invalid. */
-               try = true;
-               cur_to_new(ctrl);
+               /* Check again: it may have changed since the
+                  previous check in try_or_set_ext_ctrls(). */
+               if (set && (ctrl->flags & V4L2_CTRL_FLAG_GRABBED))
+                       return -EBUSY;
        }
 
-       /* For larger clusters you have to call try_ctrl again to
-          verify that the controls are still valid after the
-          'cur_to_new' above. */
-       if (!ret && try)
-               ret = call_op(master, try_ctrl);
+       ret = call_op(master, try_ctrl);
 
        /* Don't set if there is no change */
        if (ret || !set || !cluster_changed(master))
                return ret;
        ret = call_op(master, s_ctrl);
-       /* If OK, then make the new values permanent. */
        if (ret)
                return ret;
 
+       /* If OK, then make the new values permanent. */
        update_flag = is_cur_manual(master) != is_new_manual(master);
        for (i = 0; i < master->ncontrols; i++)
                new_to_cur(fh, master->cluster[i], update_flag && i > 0);
        return 0;
 }
 
-/* Try or set controls. */
-static int try_or_set_ext_ctrls(struct v4l2_fh *fh,
-                               struct v4l2_ctrl_handler *hdl,
-                               struct v4l2_ext_controls *cs,
-                               struct ctrl_helper *helpers,
-                               bool set)
+/* Validate controls. */
+static int validate_ctrls(struct v4l2_ext_controls *cs,
+                         struct v4l2_ctrl_helper *helpers, bool set)
 {
-       unsigned i, j;
+       unsigned i;
        int ret = 0;
 
+       cs->error_idx = cs->count;
        for (i = 0; i < cs->count; i++) {
                struct v4l2_ctrl *ctrl = helpers[i].ctrl;
 
@@ -1868,38 +1862,11 @@ static int try_or_set_ext_ctrls(struct v4l2_fh *fh,
                   best-effort to avoid that. */
                if (set && (ctrl->flags & V4L2_CTRL_FLAG_GRABBED))
                        return -EBUSY;
+               ret = validate_new(ctrl, &cs->controls[i]);
+               if (ret)
+                       return ret;
        }
-
-       for (i = 0; !ret && i < cs->count; i++) {
-               struct v4l2_ctrl *ctrl = helpers[i].ctrl;
-               struct v4l2_ctrl *master = ctrl->cluster[0];
-
-               if (helpers[i].handled)
-                       continue;
-
-               cs->error_idx = i;
-               v4l2_ctrl_lock(ctrl);
-
-               /* Reset the 'is_new' flags of the cluster */
-               for (j = 0; j < master->ncontrols; j++)
-                       if (master->cluster[j])
-                               master->cluster[j]->is_new = 0;
-
-               /* Copy the new caller-supplied control values.
-                  user_to_new() sets 'is_new' to 1. */
-               ret = cluster_walk(i, cs, helpers, user_to_new);
-
-               if (!ret)
-                       ret = try_or_set_control_cluster(fh, master, set);
-
-               /* Copy the new values back to userspace. */
-               if (!ret)
-                       ret = cluster_walk(i, cs, helpers, new_to_user);
-
-               v4l2_ctrl_unlock(ctrl);
-               cluster_done(i, cs, helpers);
-       }
-       return ret;
+       return 0;
 }
 
 /* Try or try-and-set controls */
@@ -1907,10 +1874,10 @@ static int try_set_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
                             struct v4l2_ext_controls *cs,
                             bool set)
 {
-       struct ctrl_helper helper[4];
-       struct ctrl_helper *helpers = helper;
+       struct v4l2_ctrl_helper helper[4];
+       struct v4l2_ctrl_helper *helpers = helper;
+       unsigned i, j;
        int ret;
-       int i;
 
        cs->error_idx = cs->count;
        cs->ctrl_class = V4L2_CTRL_ID2CLASS(cs->ctrl_class);
@@ -1927,20 +1894,46 @@ static int try_set_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
                        return -ENOMEM;
        }
        ret = prepare_ext_ctrls(hdl, cs, helpers);
-
-       /* First 'try' all controls and abort on error */
        if (!ret)
-               ret = try_or_set_ext_ctrls(NULL, hdl, cs, helpers, false);
-       /* If this is a 'set' operation and the initial 'try' failed,
-          then set error_idx to count to tell the application that no
-          controls changed value yet. */
-       if (set)
+               ret = validate_ctrls(cs, helpers, set);
+       if (ret && set)
                cs->error_idx = cs->count;
-       if (!ret && set) {
-               /* Reset 'handled' state */
-               for (i = 0; i < cs->count; i++)
-                       helpers[i].handled = false;
-               ret = try_or_set_ext_ctrls(fh, hdl, cs, helpers, true);
+       for (i = 0; !ret && i < cs->count; i++) {
+               struct v4l2_ctrl *master;
+               u32 idx = i;
+
+               if (helpers[i].mref == NULL)
+                       continue;
+
+               cs->error_idx = i;
+               master = helpers[i].mref->ctrl;
+               v4l2_ctrl_lock(master);
+
+               /* Reset the 'is_new' flags of the cluster */
+               for (j = 0; j < master->ncontrols; j++)
+                       if (master->cluster[j])
+                               master->cluster[j]->is_new = 0;
+
+               /* Copy the new caller-supplied control values.
+                  user_to_new() sets 'is_new' to 1. */
+               do {
+                       ret = user_to_new(cs->controls + idx, helpers[idx].ctrl);
+                       idx = helpers[idx].next;
+               } while (!ret && idx);
+
+               if (!ret)
+                       ret = try_or_set_cluster(fh, master, set);
+
+               /* Copy the new values back to userspace. */
+               if (!ret) {
+                       idx = i;
+                       do {
+                               ret = user_to_new(cs->controls + idx,
+                                               helpers[idx].ctrl);
+                               idx = helpers[idx].next;
+                       } while (!ret && idx);
+               }
+               v4l2_ctrl_unlock(master);
        }
 
        if (cs->count > ARRAY_SIZE(helper))
@@ -1980,6 +1973,10 @@ static int set_ctrl(struct v4l2_fh *fh, struct v4l2_ctrl *ctrl, s32 *val)
        int ret;
        int i;
 
+       ret = validate_new_int(ctrl, val);
+       if (ret)
+               return ret;
+
        v4l2_ctrl_lock(ctrl);
 
        /* Reset the 'is_new' flags of the cluster */
@@ -1989,9 +1986,7 @@ static int set_ctrl(struct v4l2_fh *fh, struct v4l2_ctrl *ctrl, s32 *val)
 
        ctrl->val = *val;
        ctrl->is_new = 1;
-       ret = try_or_set_control_cluster(NULL, master, false);
-       if (!ret)
-               ret = try_or_set_control_cluster(fh, master, true);
+       ret = try_or_set_cluster(fh, master, true);
        *val = ctrl->cur.val;
        v4l2_ctrl_unlock(ctrl);
        return ret;
@@ -2026,38 +2021,30 @@ int v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val)
 }
 EXPORT_SYMBOL(v4l2_ctrl_s_ctrl);
 
-void v4l2_ctrl_add_fh(struct v4l2_ctrl_handler *hdl,
-               struct v4l2_ctrl_fh *ctrl_fh,
-               struct v4l2_event_subscription *sub)
+void v4l2_ctrl_add_event(struct v4l2_ctrl *ctrl,
+                               struct v4l2_subscribed_event *sev)
 {
-       struct v4l2_ctrl *ctrl = v4l2_ctrl_find(hdl, sub->id);
-
        v4l2_ctrl_lock(ctrl);
-       list_add_tail(&ctrl_fh->node, &ctrl->fhs);
+       list_add_tail(&sev->node, &ctrl->ev_subs);
        if (ctrl->type != V4L2_CTRL_TYPE_CTRL_CLASS &&
-           (sub->flags & V4L2_EVENT_SUB_FL_SEND_INITIAL)) {
+           (sev->flags & V4L2_EVENT_SUB_FL_SEND_INITIAL)) {
                struct v4l2_event ev;
+               u32 changes = V4L2_EVENT_CTRL_CH_FLAGS;
 
-               fill_event(&ev, ctrl, V4L2_EVENT_CTRL_CH_VALUE |
-                       V4L2_EVENT_CTRL_CH_FLAGS);
-               v4l2_event_queue_fh(ctrl_fh->fh, &ev);
+               if (!(ctrl->flags & V4L2_CTRL_FLAG_WRITE_ONLY))
+                       changes |= V4L2_EVENT_CTRL_CH_VALUE;
+               fill_event(&ev, ctrl, changes);
+               v4l2_event_queue_fh(sev->fh, &ev);
        }
        v4l2_ctrl_unlock(ctrl);
 }
-EXPORT_SYMBOL(v4l2_ctrl_add_fh);
+EXPORT_SYMBOL(v4l2_ctrl_add_event);
 
-void v4l2_ctrl_del_fh(struct v4l2_ctrl *ctrl, struct v4l2_fh *fh)
+void v4l2_ctrl_del_event(struct v4l2_ctrl *ctrl,
+                               struct v4l2_subscribed_event *sev)
 {
-       struct v4l2_ctrl_fh *pos;
-
        v4l2_ctrl_lock(ctrl);
-       list_for_each_entry(pos, &ctrl->fhs, node) {
-               if (pos->fh == fh) {
-                       list_del(&pos->node);
-                       kfree(pos);
-                       break;
-               }
-       }
+       list_del(&sev->node);
        v4l2_ctrl_unlock(ctrl);
 }
-EXPORT_SYMBOL(v4l2_ctrl_del_fh);
+EXPORT_SYMBOL(v4l2_ctrl_del_event);