[PATCH v2 for 5.4 1/4] media: hantro: Fix s_fmt for dynamic resolution changes

From: Ezequiel Garcia
Date: Mon Oct 07 2019 - 13:46:53 EST


Commit 953aaa1492c53 ("media: rockchip/vpu: Prepare things to support decoders")
changed the conditions under S_FMT was allowed for OUTPUT
CAPTURE buffers.

However, and according to the mem-to-mem stateless decoder specification,
in order to support dynamic resolution changes, S_FMT should be allowed
even if OUTPUT buffers have been allocated.

Relax decoder S_FMT restrictions on OUTPUT buffers, allowing a resolution
modification, provided the pixel format stays the same.

Tested on RK3288 platforms using ChromiumOS Video Decode/Encode Accelerator Unittests.

Fixes: 953aaa1492c53 ("media: rockchip/vpu: Prepare things to support decoders")
Signed-off-by: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxx>
--
v2:
* Call try_fmt_out before using the format,
pointed out by Philipp.

drivers/staging/media/hantro/hantro_v4l2.c | 28 +++++++++++++++-------
1 file changed, 19 insertions(+), 9 deletions(-)

diff --git a/drivers/staging/media/hantro/hantro_v4l2.c b/drivers/staging/media/hantro/hantro_v4l2.c
index 3dae52abb96c..586d243cc3cc 100644
--- a/drivers/staging/media/hantro/hantro_v4l2.c
+++ b/drivers/staging/media/hantro/hantro_v4l2.c
@@ -367,19 +367,26 @@ vidioc_s_fmt_out_mplane(struct file *file, void *priv, struct v4l2_format *f)
{
struct v4l2_pix_format_mplane *pix_mp = &f->fmt.pix_mp;
struct hantro_ctx *ctx = fh_to_ctx(priv);
+ struct vb2_queue *vq = v4l2_m2m_get_vq(ctx->fh.m2m_ctx, f->type);
const struct hantro_fmt *formats;
unsigned int num_fmts;
- struct vb2_queue *vq;
int ret;

- /* Change not allowed if queue is busy. */
- vq = v4l2_m2m_get_vq(ctx->fh.m2m_ctx, f->type);
- if (vb2_is_busy(vq))
- return -EBUSY;
+ ret = vidioc_try_fmt_out_mplane(file, priv, f);
+ if (ret)
+ return ret;

if (!hantro_is_encoder_ctx(ctx)) {
struct vb2_queue *peer_vq;

+ /*
+ * In other to support dynamic resolution change,
+ * the decoder admits a resolution change, as long
+ * as the pixelformat remains. Can't be done if streaming.
+ */
+ if (vb2_is_streaming(vq) || (vb2_is_busy(vq) &&
+ pix_mp->pixelformat != ctx->src_fmt.pixelformat))
+ return -EBUSY;
/*
* Since format change on the OUTPUT queue will reset
* the CAPTURE queue, we can't allow doing so
@@ -389,12 +396,15 @@ vidioc_s_fmt_out_mplane(struct file *file, void *priv, struct v4l2_format *f)
V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE);
if (vb2_is_busy(peer_vq))
return -EBUSY;
+ } else {
+ /*
+ * The encoder doesn't admit a format change if
+ * there are OUTPUT buffers allocated.
+ */
+ if (vb2_is_busy(vq))
+ return -EBUSY;
}

- ret = vidioc_try_fmt_out_mplane(file, priv, f);
- if (ret)
- return ret;
-
formats = hantro_get_formats(ctx, &num_fmts);
ctx->vpu_src_fmt = hantro_find_format(formats, num_fmts,
pix_mp->pixelformat);
--
2.22.0