Commit eba63df7 authored by Hans Verkuil's avatar Hans Verkuil
Browse files

Revert "media: v4l2-ctrls: show all owned controls in log_status" 



This reverts commit 9801b5b2.

This patch introduced a potential deadlock scenario:

[Wed May  8 10:02:06 2024]  Possible unsafe locking scenario:

[Wed May  8 10:02:06 2024]        CPU0                    CPU1
[Wed May  8 10:02:06 2024]        ----                    ----
[Wed May  8 10:02:06 2024]   lock(vivid_ctrls:1620:(hdl_vid_cap)->_lock);
[Wed May  8 10:02:06 2024]                                lock(vivid_ctrls:1608:(hdl_user_vid)->_lock);
[Wed May  8 10:02:06 2024]                                lock(vivid_ctrls:1620:(hdl_vid_cap)->_lock);
[Wed May  8 10:02:06 2024]   lock(vivid_ctrls:1608:(hdl_user_vid)->_lock);

For now just revert.

Fixes: 9801b5b2 ("media: v4l2-ctrls: show all owned controls in log_status")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarHans Verkuil <hverkuil-cisco@xs4all.nl>
Reviewed-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
parent 69833527

drivers/media/v4l2-core/v4l2-ctrls-core.c

+5 −13
Original line number Diff line number Diff line
@@ -2507,8 +2507,7 @@ int v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl) 
EXPORT_SYMBOL(v4l2_ctrl_handler_setup);



/* Log the control name and value */

static void log_ctrl(const struct v4l2_ctrl_handler *hdl,

		     struct v4l2_ctrl *ctrl,

static void log_ctrl(const struct v4l2_ctrl *ctrl,

		     const char *prefix, const char *colon)

{

	if (ctrl->flags & (V4L2_CTRL_FLAG_DISABLED | V4L2_CTRL_FLAG_WRITE_ONLY))
@@ -2518,11 +2517,7 @@ static void log_ctrl(const struct v4l2_ctrl_handler *hdl, 


	pr_info("%s%s%s: ", prefix, colon, ctrl->name);



	if (ctrl->handler != hdl)

		v4l2_ctrl_lock(ctrl);

	ctrl->type_ops->log(ctrl);

	if (ctrl->handler != hdl)

		v4l2_ctrl_unlock(ctrl);



	if (ctrl->flags & (V4L2_CTRL_FLAG_INACTIVE |

			   V4L2_CTRL_FLAG_GRABBED |
@@ -2541,7 +2536,7 @@ static void log_ctrl(const struct v4l2_ctrl_handler *hdl, 
void v4l2_ctrl_handler_log_status(struct v4l2_ctrl_handler *hdl,

				  const char *prefix)

{

	struct v4l2_ctrl_ref *ref;

	struct v4l2_ctrl *ctrl;

	const char *colon = "";

	int len;
@@ -2553,12 +2548,9 @@ void v4l2_ctrl_handler_log_status(struct v4l2_ctrl_handler *hdl, 
	if (len && prefix[len - 1] != ' ')

		colon = ": ";

	mutex_lock(hdl->lock);

	list_for_each_entry(ref, &hdl->ctrl_refs, node) {

		if (ref->from_other_dev ||

		    (ref->ctrl->flags & V4L2_CTRL_FLAG_DISABLED))

			continue;

		log_ctrl(hdl, ref->ctrl, prefix, colon);

	}

	list_for_each_entry(ctrl, &hdl->ctrls, node)

		if (!(ctrl->flags & V4L2_CTRL_FLAG_DISABLED))

			log_ctrl(ctrl, prefix, colon);

	mutex_unlock(hdl->lock);

}

EXPORT_SYMBOL(v4l2_ctrl_handler_log_status);