[PATCH v12 07/29] media: v4l2-mem2mem: add v4l2_m2m_suspend, v4l2_m2m_resume

From: Xia Jiang
Date: Fri Aug 14 2020 - 03:13:24 EST


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>
Reviewed-by: Tomasz Figa <tfiga@xxxxxxxxxxxx>
---
v12: add this relied patch to the series
---
drivers/media/v4l2-core/v4l2-mem2mem.c | 41 ++++++++++++++++++++++++++
include/media/v4l2-mem2mem.h | 22 ++++++++++++++
2 files changed, 63 insertions(+)

diff --git a/drivers/media/v4l2-core/v4l2-mem2mem.c b/drivers/media/v4l2-core/v4l2-mem2mem.c
index 62ac9424c92a..ddfdb6375064 100644
--- a/drivers/media/v4l2-core/v4l2-mem2mem.c
+++ b/drivers/media/v4l2-core/v4l2-mem2mem.c
@@ -43,6 +43,10 @@ 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 */
@@ -84,6 +88,7 @@ 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 {
@@ -101,6 +106,7 @@ 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;
};
@@ -263,6 +269,12 @@ 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;
@@ -504,6 +516,7 @@ void v4l2_m2m_buf_done_and_job_finish(struct v4l2_m2m_dev *m2m_dev,

if (WARN_ON(!src_buf || !dst_buf))
goto unlock;
+ v4l2_m2m_buf_done(src_buf, state);
dst_buf->is_held = src_buf->flags & V4L2_BUF_FLAG_M2M_HOLD_CAPTURE_BUF;
if (!dst_buf->is_held) {
v4l2_m2m_dst_buf_remove(m2m_ctx);
@@ -528,6 +541,34 @@ void v4l2_m2m_buf_done_and_job_finish(struct v4l2_m2m_dev *m2m_dev,
}
EXPORT_SYMBOL(v4l2_m2m_buf_done_and_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 98753f00df7e..5a91b548ecc0 100644
--- a/include/media/v4l2-mem2mem.h
+++ b/include/media/v4l2-mem2mem.h
@@ -304,6 +304,28 @@ v4l2_m2m_is_last_draining_src_buf(struct v4l2_m2m_ctx *m2m_ctx,
void v4l2_m2m_last_buffer_done(struct v4l2_m2m_ctx *m2m_ctx,
struct vb2_v4l2_buffer *vbuf);

+/**
+ * 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