Hi Jerry,
On Wed, Dec 04, 2019 at 08:47:29PM +0800, Jerry-ch Chen wrote:
> From: Pi-Hsun Shih <pihsun@xxxxxxxxxxxx>
>
> Add two functions that can be used to stop new jobs from being queued /
> continue running queued job. This can be used while a driver using m2m
> helper is going to suspend / wake up from resume, and can ensure that
> there's no job running in suspend process.
>
> BUG=b:143046833
> TEST=build
>
> Signed-off-by: Pi-Hsun Shih <pihsun@xxxxxxxxxxxx>
> Signed-off-by: Jerry-ch Chen <jerry-ch.chen@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>
> ---
> drivers/media/v4l2-core/v4l2-mem2mem.c | 40 ++++++++++++++++++++++++++
> include/media/v4l2-mem2mem.h | 22 ++++++++++++++
> 2 files changed, 62 insertions(+)
>
> diff --git a/drivers/media/v4l2-core/v4l2-mem2mem.c b/drivers/media/v4l2-core/v4l2-mem2mem.c
> index 5bbdec55b7d7..76ba203e0035 100644
> --- a/drivers/media/v4l2-core/v4l2-mem2mem.c
> +++ b/drivers/media/v4l2-core/v4l2-mem2mem.c
> @@ -47,6 +47,10 @@ module_param(debug, bool, 0644);
> #define TRANS_ABORT (1 << 2)
>
>
> +/* The job queue is not running new jobs */
> +#define QUEUE_PAUSED (1 << 0)
> +
> +
> /* Offset base for buffers on the destination queue - used to distinguish
> * between source and destination buffers when mmapping - they receive the same
> * offsets but for different queues */
> @@ -88,6 +92,7 @@ static const char * const m2m_entity_name[] = {
> * @job_queue: instances queued to run
> * @job_spinlock: protects job_queue
> * @job_work: worker to run queued jobs.
> + * @job_queue_flags: flags of the queue status, %QUEUE_PAUSED.
> * @m2m_ops: driver callbacks
> */
> struct v4l2_m2m_dev {
> @@ -105,6 +110,7 @@ struct v4l2_m2m_dev {
> struct list_head job_queue;
> spinlock_t job_spinlock;
> struct work_struct job_work;
> + unsigned long job_queue_flags;
>
> const struct v4l2_m2m_ops *m2m_ops;
> };
> @@ -267,6 +273,12 @@ static void v4l2_m2m_try_run(struct v4l2_m2m_dev *m2m_dev)
> return;
> }
>
> + if (m2m_dev->job_queue_flags & QUEUE_PAUSED) {
> + spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
> + dprintk("Running new jobs is paused\n");
> + return;
> + }
> +
> m2m_dev->curr_ctx = list_first_entry(&m2m_dev->job_queue,
> struct v4l2_m2m_ctx, queue);
> m2m_dev->curr_ctx->job_flags |= TRANS_RUNNING;
> @@ -447,6 +459,34 @@ void v4l2_m2m_job_finish(struct v4l2_m2m_dev *m2m_dev,
> }
> EXPORT_SYMBOL(v4l2_m2m_job_finish);
>
> +void v4l2_m2m_suspend(struct v4l2_m2m_dev *m2m_dev)
> +{
> + unsigned long flags;
> + struct v4l2_m2m_ctx *curr_ctx;
> +
> + spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
> + m2m_dev->job_queue_flags |= QUEUE_PAUSED;
> + curr_ctx = m2m_dev->curr_ctx;
> + spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
> +
> + if (curr_ctx)
> + wait_event(curr_ctx->finished,
> + !(curr_ctx->job_flags & TRANS_RUNNING));
> +}
> +EXPORT_SYMBOL(v4l2_m2m_suspend);
> +
> +void v4l2_m2m_resume(struct v4l2_m2m_dev *m2m_dev)
> +{
> + unsigned long flags;
> +
> + spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
> + m2m_dev->job_queue_flags &= ~QUEUE_PAUSED;
> + spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
> +
> + v4l2_m2m_try_run(m2m_dev);
> +}
> +EXPORT_SYMBOL(v4l2_m2m_resume);
> +
> int v4l2_m2m_reqbufs(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
> struct v4l2_requestbuffers *reqbufs)
> {
> diff --git a/include/media/v4l2-mem2mem.h b/include/media/v4l2-mem2mem.h
> index 5467264771ec..119a195da390 100644
> --- a/include/media/v4l2-mem2mem.h
> +++ b/include/media/v4l2-mem2mem.h
> @@ -183,6 +183,28 @@ v4l2_m2m_buf_done(struct vb2_v4l2_buffer *buf, enum vb2_buffer_state state)
> vb2_buffer_done(&buf->vb2_buf, state);
> }
>
> +/**
> + * v4l2_m2m_suspend() - stop new jobs from being run and wait for current job
> + * to finish
> + *
> + * @m2m_dev: opaque pointer to the internal data to handle M2M context
> + *
> + * Called by a driver in the suspend hook. Stop new jobs from being run, and
> + * wait for current running job to finish.
> + */
> +void v4l2_m2m_suspend(struct v4l2_m2m_dev *m2m_dev);
> +
> +/**
> + * v4l2_m2m_resume() - resume job running and try to run a queued job
> + *
> + * @m2m_dev: opaque pointer to the internal data to handle M2M context
> + *
> + * Called by a driver in the resume hook. This reverts the operation of
> + * v4l2_m2m_suspend() and allows job to be run. Also try to run a queued job if
> + * there is any.
> + */
> +void v4l2_m2m_resume(struct v4l2_m2m_dev *m2m_dev);
> +
> /**
> * v4l2_m2m_reqbufs() - multi-queue-aware REQBUFS multiplexer
> *
> --
> 2.18.0
Reviewed-by: Tomasz Figa <tfiga@xxxxxxxxxxxx>
[Corrected Hans's email address.]
Hans, does this look good to you?
Best regards,
Tomasz
