On 10/05/2024 10:26, Laurent Pinchart wrote:
> On Fri, May 10, 2024 at 11:25:09AM +0300, Laurent Pinchart wrote:
>> Hi Hans,
>>
>> Thank you for the patch.
>>
>> On Fri, May 10, 2024 at 09:11:46AM +0200, Hans Verkuil wrote:
>>> This reverts commit 9801b5b28c6929139d6fceeee8d739cc67bb2739.
>>>
>>> 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: 9801b5b28c69 ("media: v4l2-ctrls: show all owned controls in log_status")
>>> Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
>>
>> Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
>
> There should be a
>
> Cc: stable@xxxxxxxxxxxxxxx
Isn't that automatic if there is a Fixes tag? I thought the stable team
automatically processes commits with that tag.
Regards,
Hans
>
> too, as this should be backported to v6.9.x.
>
>>> ---
>>> drivers/media/v4l2-core/v4l2-ctrls-core.c | 18 +++++-------------
>>> 1 file changed, 5 insertions(+), 13 deletions(-)
>>>
>>> diff --git a/drivers/media/v4l2-core/v4l2-ctrls-core.c b/drivers/media/v4l2-core/v4l2-ctrls-core.c
>>> index c59dd691f79f6..eeab6a5eb7bac 100644
>>> --- a/drivers/media/v4l2-core/v4l2-ctrls-core.c
>>> +++ b/drivers/media/v4l2-core/v4l2-ctrls-core.c
>>> @@ -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);
>
