From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Cc: linux-media@vger.kernel.org, Sakari Ailus <sakari.ailus@iki.fi>,
bingbu.cao@intel.com, hongju.wang@intel.com,
Hans Verkuil <hverkuil@xs4all.nl>,
Jacopo Mondi <jacopo.mondi@ideasonboard.com>,
Dmitry Perchanov <dmitry.perchanov@intel.com>,
Ng Khai Wen <khai.wen.ng@intel.com>,
Alain Volmat <alain.volmat@foss.st.com>
Subject: Re: [PATCH] media: uapi: v4l: Don't expose generic metadata formats to userspace
Date: Mon, 29 Apr 2024 11:33:26 +0300 [thread overview]
Message-ID: <20240429083326.GA4233@pendragon.ideasonboard.com> (raw)
In-Reply-To: <39105858-0774-4668-8120-cca8572079c9@ideasonboard.com>
On Mon, Apr 29, 2024 at 10:05:15AM +0300, Tomi Valkeinen wrote:
> On 26/04/2024 18:33, Laurent Pinchart wrote:
> > The generic metadata pixel formats (V4L2_META_FMT_GENERIC_*) are meant
> > to be used in conjunction with device-specific media bus codes. Those
> > codes are work in progress and not available in the upstream kernel yet.
> > To make sure the generic metadata pixel formats won't be used by
> > userspace until we have the full infrastructure in place, keep their
> > definition private to the kernel for now.
>
> Does it matter? How can the userspace use the generic formats, if no
> driver provides them?
I agree with you, but this series generated some level of discomfort and
voices were raised that the generic formats could be abused. Sakari and
I don't believe that's the case, but because only part of the puzzle has
been submitted for v6.10 (the device-specific media bus codes will be
for v6.11 - if all goes well), I can understand that the big picture may
appear a bit confusing for people who haven't followed the development.
I expect this patch to be reverted for v6.11.
> > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > ---
> > This patch can be squashed with "[PATCH v3 05/14] media: uapi: v4l: Add
> > generic 8-bit metadata format definitions" or kept separate.
> > ---
> > include/uapi/linux/videodev2.h | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> > index f74aca14044f..1c0bb4f9ecac 100644
> > --- a/include/uapi/linux/videodev2.h
> > +++ b/include/uapi/linux/videodev2.h
> > @@ -842,6 +842,7 @@ struct v4l2_pix_format {
> > #define V4L2_META_FMT_RK_ISP1_PARAMS v4l2_fourcc('R', 'K', '1', 'P') /* Rockchip ISP1 3A Parameters */
> > #define V4L2_META_FMT_RK_ISP1_STAT_3A v4l2_fourcc('R', 'K', '1', 'S') /* Rockchip ISP1 3A Statistics */
> >
> > +#ifdef __KERNEL__
> > /*
> > * Line-based metadata formats. Remember to update v4l_fill_fmtdesc() when
> > * adding new ones!
> > @@ -853,6 +854,7 @@ struct v4l2_pix_format {
> > #define V4L2_META_FMT_GENERIC_CSI2_16 v4l2_fourcc('M', 'C', '1', 'G') /* 16-bit CSI-2 packed 8-bit metadata */
> > #define V4L2_META_FMT_GENERIC_CSI2_20 v4l2_fourcc('M', 'C', '1', 'K') /* 20-bit CSI-2 packed 8-bit metadata */
> > #define V4L2_META_FMT_GENERIC_CSI2_24 v4l2_fourcc('M', 'C', '1', 'O') /* 24-bit CSI-2 packed 8-bit metadata */
> > +#endif
> >
> > /* priv field value to indicates that subsequent fields are valid. */
> > #define V4L2_PIX_FMT_PRIV_MAGIC 0xfeedcafe
> >
> > base-commit: 5a6272f644afa3db2f00e77ff8b0ea9df51ea875
--
Regards,
Laurent Pinchart
prev parent reply other threads:[~2024-04-29 8:33 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-26 8:50 [PATCH v3 00/14] Generic line based metadata, without sensor API changes Sakari Ailus
2024-04-26 8:50 ` [PATCH v3 01/14] media: v4l2-subdev: Clearly document that the crop API won't be extended Sakari Ailus
2024-04-26 8:50 ` [PATCH v3 02/14] media: Documentation: Add "stream" into glossary Sakari Ailus
2024-04-26 8:50 ` [PATCH v3 03/14] media: uapi: Add generic serial metadata mbus formats Sakari Ailus
2024-04-26 8:50 ` [PATCH v3 04/14] media: uapi: Document which mbus format fields are valid for metadata Sakari Ailus
2024-04-26 8:50 ` [PATCH v3 05/14] media: uapi: v4l: Add generic 8-bit metadata format definitions Sakari Ailus
2024-04-26 8:50 ` [PATCH v3 06/14] media: v4l: Support line-based metadata capture Sakari Ailus
2024-04-26 8:50 ` [PATCH v3 07/14] media: v4l: Set line based metadata flag in V4L2 core Sakari Ailus
2024-04-26 8:50 ` [PATCH v3 08/14] media: Documentation: Additional streams generally don't harm capture Sakari Ailus
2024-04-26 8:50 ` [PATCH v3 09/14] media: Documentation: Document S_ROUTING behaviour Sakari Ailus
2024-04-26 8:50 ` [PATCH v3 10/14] media: v4l: subdev: Add a function to lock two sub-device states, use it Sakari Ailus
2024-04-26 8:50 ` [PATCH v3 11/14] media: v4l: subdev: Copy argument back to user also for S_ROUTING Sakari Ailus
2024-04-26 8:50 ` [PATCH v3 12/14] media: v4l: subdev: Add len_routes field to struct v4l2_subdev_routing Sakari Ailus
2024-04-26 8:50 ` [PATCH v3 13/14] media: v4l: subdev: Return routes set using S_ROUTING Sakari Ailus
2024-04-26 8:50 ` [PATCH v3 14/14] media: v4l: subdev: Add trivial set_routing support Sakari Ailus
2024-04-26 15:33 ` [PATCH] media: uapi: v4l: Don't expose generic metadata formats to userspace Laurent Pinchart
2024-04-29 7:05 ` Tomi Valkeinen
2024-04-29 8:33 ` Laurent Pinchart [this message]
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