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This can be used to prevent > running jobs concurrently on m2m cores that have some internal resource > sharing. > > Signed-off-by: Nicolas Dufresne Also need your s-o-b, or just said refer to other thread if it already posted. Frank > --- > drivers/media/v4l2-core/v4l2-mem2mem.c | 23 +++++++++++++++++++++++ > include/media/v4l2-mem2mem.h | 21 +++++++++++++++++++++ > 2 files changed, 44 insertions(+) > > diff --git a/drivers/media/v4l2-core/v4l2-mem2mem.c b/drivers/media/v4l2-core/v4l2-mem2mem.c > index fec93c1a9231..ae0de54d4c3e 100644 > --- a/drivers/media/v4l2-core/v4l2-mem2mem.c > +++ b/drivers/media/v4l2-core/v4l2-mem2mem.c > @@ -90,6 +90,7 @@ static const char * const m2m_entity_name[] = { > * @job_work: worker to run queued jobs. > * @job_queue_flags: flags of the queue status, %QUEUE_PAUSED. > * @m2m_ops: driver callbacks > + * @kref: device reference count > */ > struct v4l2_m2m_dev { > struct v4l2_m2m_ctx *curr_ctx; > @@ -109,6 +110,8 @@ struct v4l2_m2m_dev { > unsigned long job_queue_flags; > > const struct v4l2_m2m_ops *m2m_ops; > + > + struct kref kref; > }; > > static struct v4l2_m2m_queue_ctx *get_queue_ctx(struct v4l2_m2m_ctx *m2m_ctx, > @@ -1200,6 +1203,7 @@ struct v4l2_m2m_dev *v4l2_m2m_init(const struct v4l2_m2m_ops *m2m_ops) > INIT_LIST_HEAD(&m2m_dev->job_queue); > spin_lock_init(&m2m_dev->job_spinlock); > INIT_WORK(&m2m_dev->job_work, v4l2_m2m_device_run_work); > + kref_init(&m2m_dev->kref); > > return m2m_dev; > } > @@ -1211,6 +1215,25 @@ void v4l2_m2m_release(struct v4l2_m2m_dev *m2m_dev) > } > EXPORT_SYMBOL_GPL(v4l2_m2m_release); > > +void v4l2_m2m_get(struct v4l2_m2m_dev *m2m_dev) > +{ > + kref_get(&m2m_dev->kref); > +} > +EXPORT_SYMBOL_GPL(v4l2_m2m_get); > + > +static void v4l2_m2m_release_from_kref(struct kref *kref) > +{ > + struct v4l2_m2m_dev *m2m_dev = container_of(kref, struct v4l2_m2m_dev, kref); > + > + v4l2_m2m_release(m2m_dev); > +} > + > +void v4l2_m2m_put(struct v4l2_m2m_dev *m2m_dev) > +{ > + kref_put(&m2m_dev->kref, v4l2_m2m_release_from_kref); > +} > +EXPORT_SYMBOL_GPL(v4l2_m2m_put); > + > struct v4l2_m2m_ctx *v4l2_m2m_ctx_init(struct v4l2_m2m_dev *m2m_dev, > void *drv_priv, > int (*queue_init)(void *priv, struct vb2_queue *src_vq, struct vb2_queue *dst_vq)) > diff --git a/include/media/v4l2-mem2mem.h b/include/media/v4l2-mem2mem.h > index bf6a09a04dcf..ca295c660c7f 100644 > --- a/include/media/v4l2-mem2mem.h > +++ b/include/media/v4l2-mem2mem.h > @@ -547,6 +547,27 @@ v4l2_m2m_register_media_controller(struct v4l2_m2m_dev *m2m_dev, > */ > void v4l2_m2m_release(struct v4l2_m2m_dev *m2m_dev); > > +/** > + * v4l2_m2m_get() - take a reference to the m2m_dev structure > + * > + * @m2m_dev: opaque pointer to the internal data to handle M2M context > + * > + * This is used to share the M2M device across multiple devices. This > + * can be used to avoid scheduling two hardware nodes concurrently. > + */ > +void v4l2_m2m_get(struct v4l2_m2m_dev *m2m_dev); > + > +/** > + * v4l2_m2m_put() - remove a reference to the m2m_dev structure > + * > + * @m2m_dev: opaque pointer to the internal data to handle M2M context > + * > + * Once the M2M device have no more references, v4l2_m2m_realse() will be > + * called automatically. Users of this method should never call > + * v4l2_m2m_release() directly. See v4l2_m2m_get() for more details. > + */ > +void v4l2_m2m_put(struct v4l2_m2m_dev *m2m_dev); > + > /** > * v4l2_m2m_ctx_init() - allocate and initialize a m2m context > * > -- > 2.52.0 >