On 07/05/18 19:05, Mauro Carvalho Chehab wrote:
> Em Fri, 4 May 2018 15:43:07 +0300
> Sakari Ailus <sakari.ailus@xxxxxx> escreveu:
>
>> On Thu, May 03, 2018 at 04:52:55PM +0200, Hans Verkuil wrote:
>>> From: Hans Verkuil <hans.verkuil@xxxxxxxxx>
>>>
>>> Add media_request_object_find to find a request object inside a
>>> request based on ops and/or priv values.
>>>
>>> Objects of the same type (vb2 buffer, control handler) will have
>>> the same ops value. And objects that refer to the same 'parent'
>>> object (e.g. the v4l2_ctrl_handler that has the current driver
>>> state) will have the same priv value.
>>>
>>> The caller has to call media_request_object_put() for the returned
>>> object since this function increments the refcount.
>>>
>>> Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
>>> ---
>>> drivers/media/media-request.c | 25 +++++++++++++++++++++++++
>>> include/media/media-request.h | 24 ++++++++++++++++++++++++
>>> 2 files changed, 49 insertions(+)
>>>
>>> diff --git a/drivers/media/media-request.c b/drivers/media/media-request.c
>>> index edc1c3af1959..c7e11e816e27 100644
>>> --- a/drivers/media/media-request.c
>>> +++ b/drivers/media/media-request.c
>>> @@ -322,6 +322,31 @@ static void media_request_object_release(struct kref *kref)
>>> obj->ops->release(obj);
>>> }
>>>
>>> +struct media_request_object *
>>> +media_request_object_find(struct media_request *req,
>>> + const struct media_request_object_ops *ops,
>>> + void *priv)
>>> +{
>>> + struct media_request_object *obj;
>>> + struct media_request_object *found = NULL;
>>> + unsigned long flags;
>>> +
>>> + if (WARN_ON(!ops || !priv))
>>> + return NULL;
>>> +
>>> + spin_lock_irqsave(&req->lock, flags);
>>> + list_for_each_entry(obj, &req->objects, list) {
>>> + if (obj->ops == ops && obj->priv == priv) {
>>> + media_request_object_get(obj);
>>> + found = obj;
>>> + break;
>>> + }
>>> + }
>>> + spin_unlock_irqrestore(&req->lock, flags);
>>> + return found;
>>> +}
>>> +EXPORT_SYMBOL_GPL(media_request_object_find);
>>> +
>>> void media_request_object_put(struct media_request_object *obj)
>>> {
>>> kref_put(&obj->kref, media_request_object_release);
>>> diff --git a/include/media/media-request.h b/include/media/media-request.h
>>> index 997e096d7128..5367b4a2f91c 100644
>>> --- a/include/media/media-request.h
>>> +++ b/include/media/media-request.h
>>> @@ -196,6 +196,22 @@ static inline void media_request_object_get(struct media_request_object *obj)
>>> */
>>> void media_request_object_put(struct media_request_object *obj);
>>>
>>> +/**
>>> + * media_request_object_find - Find an object in a request
>>> + *
>>> + * @ops: Find an object with this ops value
>>> + * @priv: Find an object with this priv value
>>> + *
>>> + * Both @ops and @priv must be non-NULL.
>>> + *
>>> + * Returns NULL if not found or the object pointer. The caller must
>>
>> I'd describe the successful case first. I.e. "Returns the object pointer or
>> NULL it not found".
>
> It would be good to also tell that this routine internally uses the
> spin lock.
Done.
Regards,
Hans
>
>>
>> Acked-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
>>
>>> + * call media_request_object_put() once it finished using the object.
>>> + */
>>> +struct media_request_object *
>>> +media_request_object_find(struct media_request *req,
>>> + const struct media_request_object_ops *ops,
>>> + void *priv);
>>> +
>>> /**
>>> * media_request_object_init - Initialise a media request object
>>> *
>>> @@ -241,6 +257,14 @@ static inline void media_request_object_put(struct media_request_object *obj)
>>> {
>>> }
>>>
>>> +static inline struct media_request_object *
>>> +media_request_object_find(struct media_request *req,
>>> + const struct media_request_object_ops *ops,
>>> + void *priv)
>>> +{
>>> + return NULL;
>>> +}
>>> +
>>> static inline void media_request_object_init(struct media_request_object *obj)
>>> {
>>> obj->ops = NULL;
>>
>
>
>
> Thanks,
> Mauro
>
