From 6a8ffa8b4c519419f7b926904f02c8d1fec5b488 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Niklas=20S=C3=B6derlund?= Date: Tue, 13 Mar 2018 22:49:09 -0400 Subject: media: rcar-vin: allocate a scratch buffer at stream start MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Before starting a capture, allocate a scratch buffer which can be used by the driver to give to the hardware if no buffers are available from userspace. The buffer is not used in this patch but prepares for future refactoring where the scratch buffer can be used to avoid the need to fallback on single capture mode if userspace can't queue buffers as fast as the VIN driver consumes them. Signed-off-by: Niklas Söderlund Reviewed-by: Jacopo Mondi Reviewed-by: Kieran Bingham Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- drivers/media/platform/rcar-vin/rcar-dma.c | 19 +++++++++++++++++++ drivers/media/platform/rcar-vin/rcar-vin.h | 4 ++++ 2 files changed, 23 insertions(+) (limited to 'drivers/media/platform') diff --git a/drivers/media/platform/rcar-vin/rcar-dma.c b/drivers/media/platform/rcar-vin/rcar-dma.c index 23fdff7..1f91b05 100644 --- a/drivers/media/platform/rcar-vin/rcar-dma.c +++ b/drivers/media/platform/rcar-vin/rcar-dma.c @@ -1076,6 +1076,17 @@ static int rvin_start_streaming(struct vb2_queue *vq, unsigned int count) unsigned long flags; int ret; + /* Allocate scratch buffer. */ + vin->scratch = dma_alloc_coherent(vin->dev, vin->format.sizeimage, + &vin->scratch_phys, GFP_KERNEL); + if (!vin->scratch) { + spin_lock_irqsave(&vin->qlock, flags); + return_all_buffers(vin, VB2_BUF_STATE_QUEUED); + spin_unlock_irqrestore(&vin->qlock, flags); + vin_err(vin, "Failed to allocate scratch buffer\n"); + return -ENOMEM; + } + sd = vin_to_source(vin); v4l2_subdev_call(sd, video, s_stream, 1); @@ -1091,6 +1102,10 @@ static int rvin_start_streaming(struct vb2_queue *vq, unsigned int count) spin_unlock_irqrestore(&vin->qlock, flags); + if (ret) + dma_free_coherent(vin->dev, vin->format.sizeimage, vin->scratch, + vin->scratch_phys); + return ret; } @@ -1141,6 +1156,10 @@ static void rvin_stop_streaming(struct vb2_queue *vq) /* disable interrupts */ rvin_disable_interrupts(vin); + + /* Free scratch buffer. */ + dma_free_coherent(vin->dev, vin->format.sizeimage, vin->scratch, + vin->scratch_phys); } static const struct vb2_ops rvin_qops = { diff --git a/drivers/media/platform/rcar-vin/rcar-vin.h b/drivers/media/platform/rcar-vin/rcar-vin.h index 5382078..00b405f 100644 --- a/drivers/media/platform/rcar-vin/rcar-vin.h +++ b/drivers/media/platform/rcar-vin/rcar-vin.h @@ -102,6 +102,8 @@ struct rvin_graph_entity { * * @lock: protects @queue * @queue: vb2 buffers queue + * @scratch: cpu address for scratch buffer + * @scratch_phys: physical address of the scratch buffer * * @qlock: protects @queue_buf, @buf_list, @continuous, @sequence * @state @@ -130,6 +132,8 @@ struct rvin_dev { struct mutex lock; struct vb2_queue queue; + void *scratch; + dma_addr_t scratch_phys; spinlock_t qlock; struct vb2_v4l2_buffer *queue_buf[HW_BUFFER_NUM]; -- cgit v1.1