Re: [PATCH v3 7/8] [media] s5p-jpeg: Add support for resolution change event

[Andrzej Pietrasiewicz <andrzej.p@samsung.com>]

W dniu 27.06.2017 o 18:08, Thierry Escande pisze:
> From: henryhsu <henryhsu@chromium.org>
> 
> This patch adds support for resolution change event to notify clients so
> they can prepare correct output buffer. When resolution change happened,
> G_FMT for CAPTURE should return old resolution and format before CAPTURE
> queues streamoff.
> 
> This event is used in the Chromium browser project by the V4L2 JPEG
> Decode Accelerator (V4L2JDA) to allocate output buffer.
> 
> Signed-off-by: Henry-Ruey Hsu <henryhsu@chromium.org>
> Signed-off-by: Thierry Escande <thierry.escande@collabora.com>

Acked-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>

> ---
>   drivers/media/platform/s5p-jpeg/jpeg-core.c | 106 +++++++++++++++++++++-------
>   drivers/media/platform/s5p-jpeg/jpeg-core.h |   7 ++
>   2 files changed, 89 insertions(+), 24 deletions(-)
> 
> diff --git a/drivers/media/platform/s5p-jpeg/jpeg-core.c b/drivers/media/platform/s5p-jpeg/jpeg-core.c
> index cca0fb8..5ad3d43 100644
> --- a/drivers/media/platform/s5p-jpeg/jpeg-core.c
> +++ b/drivers/media/platform/s5p-jpeg/jpeg-core.c
> @@ -24,6 +24,7 @@
>   #include <linux/slab.h>
>   #include <linux/spinlock.h>
>   #include <linux/string.h>
> +#include <media/v4l2-event.h>
>   #include <media/v4l2-mem2mem.h>
>   #include <media/v4l2-ioctl.h>
>   #include <media/videobuf2-v4l2.h>
> @@ -1633,8 +1634,6 @@ static int s5p_jpeg_s_fmt(struct s5p_jpeg_ctx *ct, struct v4l2_format *f)
>   			FMT_TYPE_OUTPUT : FMT_TYPE_CAPTURE;
>   
>   	q_data->fmt = s5p_jpeg_find_format(ct, pix->pixelformat, f_type);
> -	q_data->w = pix->width;
> -	q_data->h = pix->height;
>   	if (q_data->fmt->fourcc != V4L2_PIX_FMT_JPEG) {
>   		/*
>   		 * During encoding Exynos4x12 SoCs access wider memory area
> @@ -1642,6 +1641,8 @@ static int s5p_jpeg_s_fmt(struct s5p_jpeg_ctx *ct, struct v4l2_format *f)
>   		 * the JPEG_IMAGE_SIZE register. In order to avoid sysmmu
>   		 * page fault calculate proper buffer size in such a case.
>   		 */
> +		q_data->w = pix->width;
> +		q_data->h = pix->height;
>   		if (ct->jpeg->variant->hw_ex4_compat &&
>   		    f_type == FMT_TYPE_OUTPUT && ct->mode == S5P_JPEG_ENCODE)
>   			q_data->size = exynos4_jpeg_get_output_buffer_size(ct,
> @@ -1717,6 +1718,15 @@ static int s5p_jpeg_s_fmt_vid_out(struct file *file, void *priv,
>   	return s5p_jpeg_s_fmt(fh_to_ctx(priv), f);
>   }
>   
> +static int s5p_jpeg_subscribe_event(struct v4l2_fh *fh,
> +				    const struct v4l2_event_subscription *sub)
> +{
> +	if (sub->type == V4L2_EVENT_SOURCE_CHANGE)
> +		return v4l2_src_change_event_subscribe(fh, sub);
> +
> +	return -EINVAL;
> +}
> +
>   static int exynos3250_jpeg_try_downscale(struct s5p_jpeg_ctx *ctx,
>   				   struct v4l2_rect *r)
>   {
> @@ -2042,6 +2052,9 @@ static const struct v4l2_ioctl_ops s5p_jpeg_ioctl_ops = {
>   
>   	.vidioc_g_selection		= s5p_jpeg_g_selection,
>   	.vidioc_s_selection		= s5p_jpeg_s_selection,
> +
> +	.vidioc_subscribe_event		= s5p_jpeg_subscribe_event,
> +	.vidioc_unsubscribe_event	= v4l2_event_unsubscribe,
>   };
>   
>   /*
> @@ -2434,8 +2447,17 @@ static int s5p_jpeg_job_ready(void *priv)
>   {
>   	struct s5p_jpeg_ctx *ctx = priv;
>   
> -	if (ctx->mode == S5P_JPEG_DECODE)
> +	if (ctx->mode == S5P_JPEG_DECODE) {
> +		/*
> +		 * We have only one input buffer and one output buffer. If there
> +		 * is a resolution change event, no need to continue decoding.
> +		 */
> +		if (ctx->state == JPEGCTX_RESOLUTION_CHANGE)
> +			return 0;
> +
>   		return ctx->hdr_parsed;
> +	}
> +
>   	return 1;
>   }
>   
> @@ -2514,6 +2536,30 @@ static int s5p_jpeg_buf_prepare(struct vb2_buffer *vb)
>   	return 0;
>   }
>   
> +static void s5p_jpeg_set_capture_queue_data(struct s5p_jpeg_ctx *ctx)
> +{
> +	struct s5p_jpeg_q_data *q_data = &ctx->cap_q;
> +
> +	q_data->w = ctx->out_q.w;
> +	q_data->h = ctx->out_q.h;
> +
> +	/*
> +	 * This call to jpeg_bound_align_image() takes care of width and
> +	 * height values alignment when user space calls the QBUF of
> +	 * OUTPUT buffer after the S_FMT of CAPTURE buffer.
> +	 * Please note that on Exynos4x12 SoCs, resigning from executing
> +	 * S_FMT on capture buffer for each JPEG image can result in a
> +	 * hardware hangup if subsampling is lower than the one of input
> +	 * JPEG.
> +	 */
> +	jpeg_bound_align_image(ctx, &q_data->w, S5P_JPEG_MIN_WIDTH,
> +			       S5P_JPEG_MAX_WIDTH, q_data->fmt->h_align,
> +			       &q_data->h, S5P_JPEG_MIN_HEIGHT,
> +			       S5P_JPEG_MAX_HEIGHT, q_data->fmt->v_align);
> +
> +	q_data->size = q_data->w * q_data->h * q_data->fmt->depth >> 3;
> +}
> +
>   static void s5p_jpeg_buf_queue(struct vb2_buffer *vb)
>   {
>   	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
> @@ -2521,7 +2567,18 @@ static void s5p_jpeg_buf_queue(struct vb2_buffer *vb)
>   
>   	if (ctx->mode == S5P_JPEG_DECODE &&
>   	    vb->vb2_queue->type == V4L2_BUF_TYPE_VIDEO_OUTPUT) {
> -		struct s5p_jpeg_q_data *q_data;
> +		static const struct v4l2_event ev_src_ch = {
> +			.type = V4L2_EVENT_SOURCE_CHANGE,
> +			.u.src_change.changes = V4L2_EVENT_SRC_CH_RESOLUTION,
> +		};
> +		struct vb2_queue *dst_vq;
> +		u32 ori_w;
> +		u32 ori_h;
> +
> +		dst_vq = v4l2_m2m_get_vq(ctx->fh.m2m_ctx,
> +					 V4L2_BUF_TYPE_VIDEO_CAPTURE);
> +		ori_w = ctx->out_q.w;
> +		ori_h = ctx->out_q.h;
>   
>   		ctx->hdr_parsed = s5p_jpeg_parse_hdr(&ctx->out_q,
>   		     (unsigned long)vb2_plane_vaddr(vb, 0),
> @@ -2532,28 +2589,18 @@ static void s5p_jpeg_buf_queue(struct vb2_buffer *vb)
>   			return;
>   		}
>   
> -		q_data = &ctx->cap_q;
> -		q_data->w = ctx->out_q.w;
> -		q_data->h = ctx->out_q.h;
> -
>   		/*
> -		 * This call to jpeg_bound_align_image() takes care of width and
> -		 * height values alignment when user space calls the QBUF of
> -		 * OUTPUT buffer after the S_FMT of CAPTURE buffer.
> -		 * Please note that on Exynos4x12 SoCs, resigning from executing
> -		 * S_FMT on capture buffer for each JPEG image can result in a
> -		 * hardware hangup if subsampling is lower than the one of input
> -		 * JPEG.
> +		 * If there is a resolution change event, only update capture
> +		 * queue when it is not streaming. Otherwise, update it in
> +		 * STREAMOFF. See s5p_jpeg_stop_streaming for detail.
>   		 */
> -		jpeg_bound_align_image(ctx,
> -				       &q_data->w,
> -				       S5P_JPEG_MIN_WIDTH, S5P_JPEG_MAX_WIDTH,
> -				       q_data->fmt->h_align,
> -				       &q_data->h,
> -				       S5P_JPEG_MIN_HEIGHT, S5P_JPEG_MAX_HEIGHT,
> -				       q_data->fmt->v_align);
> -
> -		q_data->size = q_data->w * q_data->h * q_data->fmt->depth >> 3;
> +		if (ctx->out_q.w != ori_w || ctx->out_q.h != ori_h) {
> +			v4l2_event_queue_fh(&ctx->fh, &ev_src_ch);
> +			if (vb2_is_streaming(dst_vq))
> +				ctx->state = JPEGCTX_RESOLUTION_CHANGE;
> +			else
> +				s5p_jpeg_set_capture_queue_data(ctx);
> +		}
>   	}
>   
>   	v4l2_m2m_buf_queue(ctx->fh.m2m_ctx, vbuf);
> @@ -2573,6 +2620,17 @@ static void s5p_jpeg_stop_streaming(struct vb2_queue *q)
>   {
>   	struct s5p_jpeg_ctx *ctx = vb2_get_drv_priv(q);
>   
> +	/*
> +	 * STREAMOFF is an acknowledgment for resolution change event.
> +	 * Before STREAMOFF, we still have to return the old resolution and
> +	 * subsampling. Update capture queue when the stream is off.
> +	 */
> +	if (ctx->state == JPEGCTX_RESOLUTION_CHANGE &&
> +	    q->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) {
> +		s5p_jpeg_set_capture_queue_data(ctx);
> +		ctx->state = JPEGCTX_RUNNING;
> +	}
> +
>   	pm_runtime_put(ctx->jpeg->dev);
>   }
>   
> diff --git a/drivers/media/platform/s5p-jpeg/jpeg-core.h b/drivers/media/platform/s5p-jpeg/jpeg-core.h
> index 4492a35..9aa26bd 100644
> --- a/drivers/media/platform/s5p-jpeg/jpeg-core.h
> +++ b/drivers/media/platform/s5p-jpeg/jpeg-core.h
> @@ -98,6 +98,11 @@ enum  exynos4_jpeg_img_quality_level {
>   	QUALITY_LEVEL_4,	/* low */
>   };
>   
> +enum s5p_jpeg_ctx_state {
> +	JPEGCTX_RUNNING = 0,
> +	JPEGCTX_RESOLUTION_CHANGE,
> +};
> +
>   /**
>    * struct s5p_jpeg - JPEG IP abstraction
>    * @lock:		the mutex protecting this structure
> @@ -220,6 +225,7 @@ struct s5p_jpeg_q_data {
>    * @hdr_parsed:		set if header has been parsed during decompression
>    * @crop_altered:	set if crop rectangle has been altered by the user space
>    * @ctrl_handler:	controls handler
> + * @state:		state of the context
>    */
>   struct s5p_jpeg_ctx {
>   	struct s5p_jpeg		*jpeg;
> @@ -235,6 +241,7 @@ struct s5p_jpeg_ctx {
>   	bool			hdr_parsed;
>   	bool			crop_altered;
>   	struct v4l2_ctrl_handler ctrl_handler;
> +	enum s5p_jpeg_ctx_state	state;
>   };
>   
>   /**
>