From: Hans Verkuil <hans.verkuil@xxxxxxxxx>
When setting a control the control's new value is compared to the current
value twice: once by new_to_store(), once by cluster_changed(). Not a big
deal when dealing with simple values, but it can be a problem when dealing
with compound types or matrices. So fix this: cluster_changed() sets the
has_changed flag, which is used by new_to_store() instead of having to do
another compare.
Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
---
drivers/media/v4l2-core/v4l2-ctrls.c | 16 ++++++++++------
include/media/v4l2-ctrls.h | 3 +++
2 files changed, 13 insertions(+), 6 deletions(-)
diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
index 66724b7..a1c5e3e 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls.c
@@ -1389,8 +1389,10 @@ static void new_to_store(struct v4l2_fh *fh, struct v4l2_ctrl *ctrl, u32 ch_flag
if (ctrl == NULL)
return;
- changed = !ctrl->type_ops->equal(ctrl, store, ctrl->new);
- ptr_to_ptr(ctrl, ctrl->new, store);
+
+ changed = ctrl->has_changed;
+ if (changed)
+ ptr_to_ptr(ctrl, ctrl->new, store);
if (ch_flags & V4L2_EVENT_CTRL_CH_FLAGS) {
/* Note: CH_FLAGS is only set for auto clusters. */
@@ -1436,17 +1438,19 @@ static void store_to_new(struct v4l2_ctrl *ctrl, unsigned store)
value that differs from the current value. */
static int cluster_changed(struct v4l2_ctrl *master)
{
- int diff = 0;
+ bool changed = false;
int i;
- for (i = 0; !diff && i < master->ncontrols; i++) {
+ for (i = 0; i < master->ncontrols; i++) {
struct v4l2_ctrl *ctrl = master->cluster[i];
if (ctrl == NULL)
continue;
- diff = !ctrl->type_ops->equal(ctrl, ctrl->stores[0], ctrl->new);
+ ctrl->has_changed = !ctrl->type_ops->equal(ctrl,
+ ctrl->stores[0], ctrl->new);
+ changed |= ctrl->has_changed;
}
- return diff;
+ return changed;
}
/* Control range checking */
diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
index 2b9b2da..9ce740d 100644
--- a/include/media/v4l2-ctrls.h
+++ b/include/media/v4l2-ctrls.h
@@ -99,6 +99,8 @@ typedef void (*v4l2_ctrl_notify_fnc)(struct v4l2_ctrl *ctrl, void *priv);
* @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.
+ * @has_changed: Set when the current value differs from the new value. Drivers
+ * should never use 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.
@@ -165,6 +167,7 @@ struct v4l2_ctrl {
unsigned int done:1;
unsigned int is_new:1;
+ unsigned int has_changed:1;
unsigned int is_private:1;
unsigned int is_auto:1;
unsigned int is_int:1;
--
1.8.5.2
--
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