On 10/05/2024 10:40, Hans Verkuil wrote:
> 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.
Ah, I read up on it and:
"Note: Attaching a Fixes: tag does not subvert the stable kernel rules
process nor the requirement to Cc: stable@xxxxxxxxxxxxxxx on all stable
patch candidates. For more information, please read
Documentation/process/stable-kernel-rules.rst."
So you are right, and I will also update my check ensuring that if there
is a fixes tag, then there should be a CC stable as well.
Regards,
Hans
>
> 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);
>>
>
>
