| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <20260210175035.GB2502896@killaraus.ideasonboard.com>
Date: Tue, 10 Feb 2026 19:50:35 +0200
From: Laurent Pinchart <laurent.pinchart@...asonboard.com>
To: Stefan Klug <stefan.klug@...asonboard.com>
Cc: Xavier Roumegue <xavier.roumegue@....nxp.com>,
Mauro Carvalho Chehab <mchehab@...nel.org>,
Sebastian Andrzej Siewior <bigeasy@...utronix.de>,
Clark Williams <clrkwllms@...nel.org>,
Steven Rostedt <rostedt@...dmis.org>, linux-media@...r.kernel.org,
linux-kernel@...r.kernel.org, linux-rt-devel@...ts.linux.dev,
Nicolas Dufresne <nicolas@...fresne.ca>
Subject: Re: [PATCH v3 1/4] media: dw100: Implement V4L2 requests support
Hi Stefan,
Thank you for the patch.
On Thu, Jan 29, 2026 at 12:43:10PM +0100, Stefan Klug wrote:
> The dw100 dewarper hardware present on the NXP i.MX8MP allows very
> flexible dewarping using a freely configurable vertex map. Aside from
> lens dewarping the vertex map can be used to implement things like
> arbitrary zoom, pan and rotation. The current driver supports setting
> that vertex map before calling VIDIOC_STREAMON.
>
> To control above mentioned features during streaming it is necessary to
> update the vertex map dynamically. To do that in a race free manner V4L2
> requests support is required. This patch adds V4L2 requests support to
Once this gets merged it won't be a patch any more :-) As commit
messages are written in an imperative mood style,
s/This patch adds/Add/
> prepare for dynamic vertex map updates.
>
> Signed-off-by: Stefan Klug <stefan.klug@...asonboard.com>
>
> ---
>
> Changes in v2:
> - Use v4l2_m2m_buf_done_and_job_finish() to mark the buffers as done in
> the correct order.
>
> Changes in v1:
> - Moved v4l2_ctrl_request_complete into dw100_device_run
> ---
> drivers/media/platform/nxp/dw100/dw100.c | 49 +++++++++++++++++++++++++-------
> 1 file changed, 38 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/media/platform/nxp/dw100/dw100.c b/drivers/media/platform/nxp/dw100/dw100.c
> index 4aaf9c3fff5397f0441944ee926f2c8ba6fc864a..1cb895da9912371a2b23ca62412c572d9cb75c00 100644
> --- a/drivers/media/platform/nxp/dw100/dw100.c
> +++ b/drivers/media/platform/nxp/dw100/dw100.c
> @@ -459,6 +459,15 @@ static int dw100_queue_setup(struct vb2_queue *vq,
> return 0;
> }
>
> +static int dw100_buf_out_validate(struct vb2_buffer *vb)
> +{
> + struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
> +
> + vbuf->field = V4L2_FIELD_NONE;
> +
> + return 0;
> +}
> +
> static int dw100_buf_prepare(struct vb2_buffer *vb)
> {
> unsigned int i;
> @@ -500,6 +509,13 @@ static void dw100_buf_queue(struct vb2_buffer *vb)
> v4l2_m2m_buf_queue(ctx->fh.m2m_ctx, vbuf);
> }
>
> +static void dw100_buf_request_complete(struct vb2_buffer *vb)
> +{
> + struct dw100_ctx *ctx = vb2_get_drv_priv(vb->vb2_queue);
> +
> + v4l2_ctrl_request_complete(vb->req_obj.req, &ctx->hdl);
> +}
> +
> static void dw100_return_all_buffers(struct vb2_queue *q,
> enum vb2_buffer_state state)
> {
> @@ -553,11 +569,13 @@ static void dw100_stop_streaming(struct vb2_queue *q)
> }
>
> static const struct vb2_ops dw100_qops = {
> - .queue_setup = dw100_queue_setup,
> - .buf_prepare = dw100_buf_prepare,
> - .buf_queue = dw100_buf_queue,
> - .start_streaming = dw100_start_streaming,
> - .stop_streaming = dw100_stop_streaming,
> + .queue_setup = dw100_queue_setup,
> + .buf_out_validate = dw100_buf_out_validate,
> + .buf_prepare = dw100_buf_prepare,
> + .buf_queue = dw100_buf_queue,
> + .start_streaming = dw100_start_streaming,
> + .stop_streaming = dw100_stop_streaming,
> + .buf_request_complete = dw100_buf_request_complete,
> };
>
> static int dw100_m2m_queue_init(void *priv, struct vb2_queue *src_vq,
> @@ -575,6 +593,7 @@ static int dw100_m2m_queue_init(void *priv, struct vb2_queue *src_vq,
> src_vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
> src_vq->lock = &ctx->vq_mutex;
> src_vq->dev = ctx->dw_dev->v4l2_dev.dev;
> + src_vq->supports_requests = true;
>
> ret = vb2_queue_init(src_vq);
> if (ret)
> @@ -1058,7 +1077,6 @@ static const struct v4l2_ioctl_ops dw100_ioctl_ops = {
> static void dw100_job_finish(struct dw100_device *dw_dev, bool with_error)
> {
> struct dw100_ctx *curr_ctx;
> - struct vb2_v4l2_buffer *src_vb, *dst_vb;
> enum vb2_buffer_state buf_state;
>
> curr_ctx = v4l2_m2m_get_curr_priv(dw_dev->m2m_dev);
> @@ -1069,16 +1087,13 @@ static void dw100_job_finish(struct dw100_device *dw_dev, bool with_error)
> return;
> }
>
> - src_vb = v4l2_m2m_src_buf_remove(curr_ctx->fh.m2m_ctx);
> - dst_vb = v4l2_m2m_dst_buf_remove(curr_ctx->fh.m2m_ctx);
> -
> if (likely(!with_error))
> buf_state = VB2_BUF_STATE_DONE;
> else
> buf_state = VB2_BUF_STATE_ERROR;
>
> - v4l2_m2m_buf_done(src_vb, buf_state);
> - v4l2_m2m_buf_done(dst_vb, buf_state);
> + v4l2_m2m_buf_done_and_job_finish(dw_dev->m2m_dev, curr_ctx->fh.m2m_ctx,
> + buf_state);
>
> dev_dbg(&dw_dev->pdev->dev, "Finishing transaction with%s error(s)\n",
> with_error ? "" : "out");
> @@ -1460,6 +1475,12 @@ static void dw100_device_run(void *priv)
> src_buf = v4l2_m2m_next_src_buf(ctx->fh.m2m_ctx);
> dst_buf = v4l2_m2m_next_dst_buf(ctx->fh.m2m_ctx);
>
I'd add a comment here, as the complete() call before start() can be
confusing.
/*
* Apply controls from the request to the device and copy back the value
* of volatile controls to the request. We can do the latter before
* starting the dewarper as no controls are updated as a result of the
* hardware operation.
/
It could be me not being familiar enough with the API, but I think
discussions during review of v2 showed that this confused other people
too.
Reviewed-by: Laurent Pinchart <laurent.pinchart@...asonboard.com>
> + v4l2_ctrl_request_setup(src_buf->vb2_buf.req_obj.req,
> + &ctx->hdl);
> +
> + v4l2_ctrl_request_complete(src_buf->vb2_buf.req_obj.req,
> + &ctx->hdl);
> +
> dw100_start(ctx, src_buf, dst_buf);
> }
>
> @@ -1467,6 +1488,11 @@ static const struct v4l2_m2m_ops dw100_m2m_ops = {
> .device_run = dw100_device_run,
> };
>
> +static const struct media_device_ops dw100_m2m_media_ops = {
> + .req_validate = vb2_request_validate,
> + .req_queue = v4l2_m2m_request_queue,
> +};
> +
> static struct video_device *dw100_init_video_device(struct dw100_device *dw_dev)
> {
> struct video_device *vfd = &dw_dev->vfd;
> @@ -1578,6 +1604,7 @@ static int dw100_probe(struct platform_device *pdev)
> dw_dev->mdev.dev = &pdev->dev;
> strscpy(dw_dev->mdev.model, "dw100", sizeof(dw_dev->mdev.model));
> media_device_init(&dw_dev->mdev);
> + dw_dev->mdev.ops = &dw100_m2m_media_ops;
> dw_dev->v4l2_dev.mdev = &dw_dev->mdev;
>
> ret = video_register_device(vfd, VFL_TYPE_VIDEO, -1);
--
Regards,
Laurent Pinchart
Powered by blists - more mailing lists