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From dc9b786e4b9a1262b536b3c9d0fa88e34a2b3f8f Mon Sep 17 00:00:00 2001
From: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Date: Fri, 11 Oct 2019 06:32:41 -0300
Subject: [PATCH] media: v4l2-mem2mem: support held capture buffers
Commit f8cca8c97a63d77f48334cde81d15014f43530ef upstream.
Check for held buffers that are ready to be returned to vb2 in
__v4l2_m2m_try_queue(). This avoids drivers having to handle this
case.
Add v4l2_m2m_buf_done_and_job_finish() to correctly return source
and destination buffers and mark the job as finished while taking
a held destination buffer into account (i.e. that buffer won't be
returned). This has to be done while job_spinlock is held to avoid
race conditions.
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
---
drivers/media/v4l2-core/v4l2-mem2mem.c | 130 ++++++++++++++++++-------
include/media/v4l2-mem2mem.h | 33 ++++++-
2 files changed, 128 insertions(+), 35 deletions(-)
--- a/drivers/media/v4l2-core/v4l2-mem2mem.c
+++ b/drivers/media/v4l2-core/v4l2-mem2mem.c
@@ -284,7 +284,8 @@ static void v4l2_m2m_try_run(struct v4l2
static void __v4l2_m2m_try_queue(struct v4l2_m2m_dev *m2m_dev,
struct v4l2_m2m_ctx *m2m_ctx)
{
- unsigned long flags_job, flags_out, flags_cap;
+ unsigned long flags_job;
+ struct vb2_v4l2_buffer *dst, *src;
dprintk("Trying to schedule a job for m2m_ctx: %p\n", m2m_ctx);
@@ -307,20 +308,30 @@ static void __v4l2_m2m_try_queue(struct
goto job_unlock;
}
- spin_lock_irqsave(&m2m_ctx->out_q_ctx.rdy_spinlock, flags_out);
- if (list_empty(&m2m_ctx->out_q_ctx.rdy_queue)
- && !m2m_ctx->out_q_ctx.buffered) {
+ src = v4l2_m2m_next_src_buf(m2m_ctx);
+ dst = v4l2_m2m_next_dst_buf(m2m_ctx);
+ if (!src && !m2m_ctx->out_q_ctx.buffered) {
dprintk("No input buffers available\n");
- goto out_unlock;
+ goto job_unlock;
}
- spin_lock_irqsave(&m2m_ctx->cap_q_ctx.rdy_spinlock, flags_cap);
- if (list_empty(&m2m_ctx->cap_q_ctx.rdy_queue)
- && !m2m_ctx->cap_q_ctx.buffered) {
+ if (!dst && !m2m_ctx->cap_q_ctx.buffered) {
dprintk("No output buffers available\n");
- goto cap_unlock;
+ goto job_unlock;
+ }
+
+ if (src && dst &&
+ dst->is_held && dst->vb2_buf.copied_timestamp &&
+ dst->vb2_buf.timestamp != src->vb2_buf.timestamp) {
+ dst->is_held = false;
+ v4l2_m2m_dst_buf_remove(m2m_ctx);
+ v4l2_m2m_buf_done(dst, VB2_BUF_STATE_DONE);
+ dst = v4l2_m2m_next_dst_buf(m2m_ctx);
+
+ if (!dst && !m2m_ctx->cap_q_ctx.buffered) {
+ dprintk("No output buffers available after returning held buffer\n");
+ goto job_unlock;
+ }
}
- spin_unlock_irqrestore(&m2m_ctx->cap_q_ctx.rdy_spinlock, flags_cap);
- spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock, flags_out);
if (m2m_dev->m2m_ops->job_ready
&& (!m2m_dev->m2m_ops->job_ready(m2m_ctx->priv))) {
@@ -331,13 +342,6 @@ static void __v4l2_m2m_try_queue(struct
list_add_tail(&m2m_ctx->queue, &m2m_dev->job_queue);
m2m_ctx->job_flags |= TRANS_QUEUED;
- spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
- return;
-
-cap_unlock:
- spin_unlock_irqrestore(&m2m_ctx->cap_q_ctx.rdy_spinlock, flags_cap);
-out_unlock:
- spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock, flags_out);
job_unlock:
spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
}
@@ -412,37 +416,97 @@ static void v4l2_m2m_cancel_job(struct v
}
}
-void v4l2_m2m_job_finish(struct v4l2_m2m_dev *m2m_dev,
- struct v4l2_m2m_ctx *m2m_ctx)
+/*
+ * Schedule the next job, called from v4l2_m2m_job_finish() or
+ * v4l2_m2m_buf_done_and_job_finish().
+ */
+static void v4l2_m2m_schedule_next_job(struct v4l2_m2m_dev *m2m_dev,
+ struct v4l2_m2m_ctx *m2m_ctx)
{
- unsigned long flags;
+ /*
+ * This instance might have more buffers ready, but since we do not
+ * allow more than one job on the job_queue per instance, each has
+ * to be scheduled separately after the previous one finishes.
+ */
+ __v4l2_m2m_try_queue(m2m_dev, m2m_ctx);
- spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
+ /*
+ * We might be running in atomic context,
+ * but the job must be run in non-atomic context.
+ */
+ schedule_work(&m2m_dev->job_work);
+}
+
+/*
+ * Assumes job_spinlock is held, called from v4l2_m2m_job_finish() or
+ * v4l2_m2m_buf_done_and_job_finish().
+ */
+static bool _v4l2_m2m_job_finish(struct v4l2_m2m_dev *m2m_dev,
+ struct v4l2_m2m_ctx *m2m_ctx)
+{
if (!m2m_dev->curr_ctx || m2m_dev->curr_ctx != m2m_ctx) {
- spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
dprintk("Called by an instance not currently running\n");
- return;
+ return false;
}
list_del(&m2m_dev->curr_ctx->queue);
m2m_dev->curr_ctx->job_flags &= ~(TRANS_QUEUED | TRANS_RUNNING);
wake_up(&m2m_dev->curr_ctx->finished);
m2m_dev->curr_ctx = NULL;
+ return true;
+}
- spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
-
- /* This instance might have more buffers ready, but since we do not
- * allow more than one job on the job_queue per instance, each has
- * to be scheduled separately after the previous one finishes. */
- __v4l2_m2m_try_queue(m2m_dev, m2m_ctx);
+void v4l2_m2m_job_finish(struct v4l2_m2m_dev *m2m_dev,
+ struct v4l2_m2m_ctx *m2m_ctx)
+{
+ unsigned long flags;
+ bool schedule_next;
- /* We might be running in atomic context,
- * but the job must be run in non-atomic context.
+ /*
+ * This function should not be used for drivers that support
+ * holding capture buffers. Those should use
+ * v4l2_m2m_buf_done_and_job_finish() instead.
*/
- schedule_work(&m2m_dev->job_work);
+ WARN_ON(m2m_ctx->cap_q_ctx.q.subsystem_flags &
+ VB2_V4L2_FL_SUPPORTS_M2M_HOLD_CAPTURE_BUF);
+ spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
+ schedule_next = _v4l2_m2m_job_finish(m2m_dev, m2m_ctx);
+ spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
+
+ if (schedule_next)
+ v4l2_m2m_schedule_next_job(m2m_dev, m2m_ctx);
}
EXPORT_SYMBOL(v4l2_m2m_job_finish);
+void v4l2_m2m_buf_done_and_job_finish(struct v4l2_m2m_dev *m2m_dev,
+ struct v4l2_m2m_ctx *m2m_ctx,
+ enum vb2_buffer_state state)
+{
+ struct vb2_v4l2_buffer *src_buf, *dst_buf;
+ bool schedule_next = false;
+ unsigned long flags;
+
+ spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
+ src_buf = v4l2_m2m_src_buf_remove(m2m_ctx);
+ dst_buf = v4l2_m2m_next_dst_buf(m2m_ctx);
+
+ 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);
+ v4l2_m2m_buf_done(dst_buf, state);
+ }
+ schedule_next = _v4l2_m2m_job_finish(m2m_dev, m2m_ctx);
+unlock:
+ spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
+
+ if (schedule_next)
+ v4l2_m2m_schedule_next_job(m2m_dev, m2m_ctx);
+}
+EXPORT_SYMBOL(v4l2_m2m_buf_done_and_job_finish);
+
int v4l2_m2m_reqbufs(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
struct v4l2_requestbuffers *reqbufs)
{
--- a/include/media/v4l2-mem2mem.h
+++ b/include/media/v4l2-mem2mem.h
@@ -21,7 +21,8 @@
* callback.
* The job does NOT have to end before this callback returns
* (and it will be the usual case). When the job finishes,
- * v4l2_m2m_job_finish() has to be called.
+ * v4l2_m2m_job_finish() or v4l2_m2m_buf_done_and_job_finish()
+ * has to be called.
* @job_ready: optional. Should return 0 if the driver does not have a job
* fully prepared to run yet (i.e. it will not be able to finish a
* transaction without sleeping). If not provided, it will be
@@ -33,7 +34,8 @@
* stop the device safely; e.g. in the next interrupt handler),
* even if the transaction would not have been finished by then.
* After the driver performs the necessary steps, it has to call
- * v4l2_m2m_job_finish() (as if the transaction ended normally).
+ * v4l2_m2m_job_finish() or v4l2_m2m_buf_done_and_job_finish() as
+ * if the transaction ended normally.
* This function does not have to (and will usually not) wait
* until the device enters a state when it can be stopped.
*/
@@ -173,6 +175,33 @@ void v4l2_m2m_try_schedule(struct v4l2_m
void v4l2_m2m_job_finish(struct v4l2_m2m_dev *m2m_dev,
struct v4l2_m2m_ctx *m2m_ctx);
+/**
+ * v4l2_m2m_buf_done_and_job_finish() - return source/destination buffers with
+ * state and inform the framework that a job has been finished and have it
+ * clean up
+ *
+ * @m2m_dev: opaque pointer to the internal data to handle M2M context
+ * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
+ * @state: vb2 buffer state passed to v4l2_m2m_buf_done().
+ *
+ * Drivers that set V4L2_BUF_CAP_SUPPORTS_M2M_HOLD_CAPTURE_BUF must use this
+ * function instead of job_finish() to take held buffers into account. It is
+ * optional for other drivers.
+ *
+ * This function removes the source buffer from the ready list and returns
+ * it with the given state. The same is done for the destination buffer, unless
+ * it is marked 'held'. In that case the buffer is kept on the ready list.
+ *
+ * After that the job is finished (see job_finish()).
+ *
+ * This allows for multiple output buffers to be used to fill in a single
+ * capture buffer. This is typically used by stateless decoders where
+ * multiple e.g. H.264 slices contribute to a single decoded frame.
+ */
+void v4l2_m2m_buf_done_and_job_finish(struct v4l2_m2m_dev *m2m_dev,
+ struct v4l2_m2m_ctx *m2m_ctx,
+ enum vb2_buffer_state state);
+
static inline void
v4l2_m2m_buf_done(struct vb2_v4l2_buffer *buf, enum vb2_buffer_state state)
{
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