From: Hans Verkuil <hans.verk...@cisco.com>

To store request data the handler_new_ref() allocates memory
for it if needed.

Signed-off-by: Hans Verkuil <hans.verk...@cisco.com>
---
 drivers/media/v4l2-core/v4l2-ctrls.c | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c 
b/drivers/media/v4l2-core/v4l2-ctrls.c
index b33a8bee82b0..171ab389afdd 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls.c
@@ -2018,13 +2018,18 @@ EXPORT_SYMBOL(v4l2_ctrl_find);
 /* Allocate a new v4l2_ctrl_ref and hook it into the handler. */
 static int handler_new_ref(struct v4l2_ctrl_handler *hdl,
                           struct v4l2_ctrl *ctrl,
-                          bool from_other_dev)
+                          struct v4l2_ctrl_ref **ctrl_ref,
+                          bool from_other_dev, bool allocate_req)
 {
        struct v4l2_ctrl_ref *ref;
        struct v4l2_ctrl_ref *new_ref;
        u32 id = ctrl->id;
        u32 class_ctrl = V4L2_CTRL_ID2WHICH(id) | 1;
        int bucket = id % hdl->nr_of_buckets;   /* which bucket to use */
+       unsigned int sz_extra = 0;
+
+       if (ctrl_ref)
+               *ctrl_ref = NULL;
 
        /*
         * Automatically add the control class if it is not yet present and
@@ -2038,11 +2043,16 @@ static int handler_new_ref(struct v4l2_ctrl_handler 
*hdl,
        if (hdl->error)
                return hdl->error;
 
-       new_ref = kzalloc(sizeof(*new_ref), GFP_KERNEL);
+       if (allocate_req)
+               sz_extra = ctrl->elems * ctrl->elem_size;
+       new_ref = kzalloc(sizeof(*new_ref) + sz_extra, GFP_KERNEL);
        if (!new_ref)
                return handler_set_err(hdl, -ENOMEM);
        new_ref->ctrl = ctrl;
        new_ref->from_other_dev = from_other_dev;
+       if (sz_extra)
+               new_ref->p_req.p = &new_ref[1];
+
        if (ctrl->handler == hdl) {
                /* By default each control starts in a cluster of its own.
                   new_ref->ctrl is basically a cluster array with one
@@ -2082,6 +2092,8 @@ static int handler_new_ref(struct v4l2_ctrl_handler *hdl,
        /* Insert the control node in the hash */
        new_ref->next = hdl->buckets[bucket];
        hdl->buckets[bucket] = new_ref;
+       if (ctrl_ref)
+               *ctrl_ref = new_ref;
 
 unlock:
        mutex_unlock(hdl->lock);
@@ -2223,7 +2235,7 @@ static struct v4l2_ctrl *v4l2_ctrl_new(struct 
v4l2_ctrl_handler *hdl,
                ctrl->type_ops->init(ctrl, idx, ctrl->p_new);
        }
 
-       if (handler_new_ref(hdl, ctrl, false)) {
+       if (handler_new_ref(hdl, ctrl, NULL, false, false)) {
                kvfree(ctrl);
                return NULL;
        }
@@ -2416,7 +2428,7 @@ int v4l2_ctrl_add_handler(struct v4l2_ctrl_handler *hdl,
                /* Filter any unwanted controls */
                if (filter && !filter(ctrl))
                        continue;
-               ret = handler_new_ref(hdl, ctrl, from_other_dev);
+               ret = handler_new_ref(hdl, ctrl, NULL, from_other_dev, false);
                if (ret)
                        break;
        }
-- 
2.18.0

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