Hi, Pawel and Marek, I would really like to hear your opinions on this patch. I remember that the assumption of the mem2mem framework (not to be confused with mem2mem type of devices) was that it was for simple devices where one output buffer was equivalent to one capture buffer. More complicated devices were supposed to use videobuf2 directly. Please state your opinions. Best wishes, -- Kamil Debski Linux Kernel Developer Samsung R&D Institute Poland > -----Original Message----- > From: Philipp Zabel [mailto:p.zabel@xxxxxxxxxxxxxx] > Sent: Monday, June 03, 2013 10:24 AM > To: linux-media@xxxxxxxxxxxxxxx > Cc: Sylwester Nawrocki; Mauro Carvalho Chehab; Pawel Osciak; John Sheu; > Hans Verkuil; Kamil Debski; Andrzej Hajda; Philipp Zabel > Subject: [PATCH v4] [media] mem2mem: add support for hardware buffered > queue > > On mem2mem decoders with a hardware bitstream ringbuffer, to drain the > buffer at the end of the stream, remaining frames might need to be > decoded from the bitstream buffer without additional input buffers > being provided. > To achieve this, allow a queue to be marked as buffered by the driver, > and allow scheduling of device_runs when buffered ready queues are > empty. > > This also allows a driver to copy input buffers into their bitstream > ringbuffer and immediately mark them as done to be dequeued. > > The motivation for this patch is hardware assisted h.264 reordering > support in the coda driver. For high profile streams, the coda can hold > back out-of-order frames, causing a few mem2mem device runs in the > beginning, that don't produce any decompressed buffer at the v4l2 > capture side. At the same time, the last few frames can be decoded from > the bitstream with mem2mem device runs that don't need a new input > buffer at the v4l2 output side. The decoder command ioctl can be used > to put the decoder into the ringbuffer draining end-of-stream mode. > > Signed-off-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx> > --- > Changes since v3: > - Split queue_set_buffered into set_src_buffered and set_dst_buffered, > which > take a v4l2_m2m_ctx pointer instead of a vb2_queue (which isn't > guaranteed > to be embedded in a v4l2_m2m_queue_ctx). > - Make them static inline. > --- > drivers/media/v4l2-core/v4l2-mem2mem.c | 10 ++++++++-- > include/media/v4l2-mem2mem.h | 13 +++++++++++++ > 2 files changed, 21 insertions(+), 2 deletions(-) > > diff --git a/drivers/media/v4l2-core/v4l2-mem2mem.c > b/drivers/media/v4l2-core/v4l2-mem2mem.c > index 66f599f..1007e60 100644 > --- a/drivers/media/v4l2-core/v4l2-mem2mem.c > +++ b/drivers/media/v4l2-core/v4l2-mem2mem.c > @@ -196,6 +196,10 @@ static void v4l2_m2m_try_run(struct v4l2_m2m_dev > *m2m_dev) > * 2) at least one destination buffer has to be queued, > * 3) streaming has to be on. > * > + * If a queue is buffered (for example a decoder hardware ringbuffer > + that has > + * to be drained before doing streamoff), allow scheduling without > v4l2 > + buffers > + * on that queue. > + * > * There may also be additional, custom requirements. In such case the > driver > * should supply a custom callback (job_ready in v4l2_m2m_ops) that > should > * return 1 if the instance is ready. > @@ -224,14 +228,16 @@ static void v4l2_m2m_try_schedule(struct > v4l2_m2m_ctx *m2m_ctx) > } > > spin_lock_irqsave(&m2m_ctx->out_q_ctx.rdy_spinlock, flags); > - if (list_empty(&m2m_ctx->out_q_ctx.rdy_queue)) { > + if (list_empty(&m2m_ctx->out_q_ctx.rdy_queue) > + && !m2m_ctx->out_q_ctx.buffered) { > spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock, > flags); > spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job); > dprintk("No input buffers available\n"); > return; > } > spin_lock_irqsave(&m2m_ctx->cap_q_ctx.rdy_spinlock, flags); > - if (list_empty(&m2m_ctx->cap_q_ctx.rdy_queue)) { > + if (list_empty(&m2m_ctx->cap_q_ctx.rdy_queue) > + && !m2m_ctx->cap_q_ctx.buffered) { > spin_unlock_irqrestore(&m2m_ctx->cap_q_ctx.rdy_spinlock, > flags); > spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock, > flags); > spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job); > diff --git a/include/media/v4l2-mem2mem.h b/include/media/v4l2- > mem2mem.h index d3eef01..a8e1bb3 100644 > --- a/include/media/v4l2-mem2mem.h > +++ b/include/media/v4l2-mem2mem.h > @@ -60,6 +60,7 @@ struct v4l2_m2m_queue_ctx { > struct list_head rdy_queue; > spinlock_t rdy_spinlock; > u8 num_rdy; > + bool buffered; > }; > > struct v4l2_m2m_ctx { > @@ -132,6 +133,18 @@ 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)); > > +static inline void v4l2_m2m_set_src_buffered(struct v4l2_m2m_ctx > *m2m_ctx, > + bool buffered) > +{ > + m2m_ctx->out_q_ctx.buffered = buffered; } > + > +static inline void v4l2_m2m_set_dst_buffered(struct v4l2_m2m_ctx > *m2m_ctx, > + bool buffered) > +{ > + m2m_ctx->cap_q_ctx.buffered = buffered; } > + > void v4l2_m2m_ctx_release(struct v4l2_m2m_ctx *m2m_ctx); > > void v4l2_m2m_buf_queue(struct v4l2_m2m_ctx *m2m_ctx, struct > vb2_buffer *vb); > -- > 1.8.2.rc2 -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
