Hi Mikhail On Mon, Oct 21, 2024 at 05:29:33PM +0300, Mikhail Rudenko wrote: > > Hi, Sakari! > > On 2024-10-11 at 10:55 +03, Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx> wrote: > > > Hello everyone, > > > > I've been recently working (with others) on sub-device streams support as > > well as on internal pads. The two can be used to make sub-device > > configuration more versatile. > > > > At the same time, the added interfaces are much more useful if we require > > specific semantics of those interfaces, so that the user space knows > > exactly what e.g. a given selection target signifies. However, as the same > > selection rectangle could be used for a different purpose on a non-raw > > sensor device, we need a way to tell how should the user space determine > > how to use a given interface. > > > > I'm proposing to solve this problem by introducing sub-device > > configuration models, and by the common raw sensor model, also present in > > this patchset, in particular. > > > > This has been (and will, for some time, continue to be) the reason why I > > have reviewed few sensor driver related patches lately. As we're > > introducing a new interface, it's beneficial to be able to use that > > interface right from the start, rather than trying to later on offer > > compatibility support, which is almost always a fair amount of work with > > less than desirable results in the driver. > > > > With this solved, I believe we can enable the use of the streams UAPI. > > > > Comments are welcome. > > > > The compiled documentation can be found in > > <URL:https://www.retiisi.eu/~sailus/v4l2/tmp/meta-format/output/userspace-api/media/v4l/dev-subdev.html#sub-device-configuration-models> > > and the patches here > > <URL:https://git.linuxtv.org/sailus/media_tree.git/log/?h=metadata>, i.e. > > they're on top of the metadata set. > > I've read the updated documentation you shared, and have a question > concerning binning configuration. IIUC binning should be configured via > set_selection(V4L2_SEL_TGT_COMPOSE). But I also see some existing set_selection(V4L2_SEL_TGT_COMPOSE) on the internal image pad, stream #0 > drivers configure binning via set_fmt() (imx296) or both set_fmt() and > set_selection(V4L2_SEL_TGT_COMPOSE) (imx274). What will be the right way Existing drivers have adopted creative solutions to allow control of the binning factor but all of them are somewhat non-compliant with the specs (we went in great lenght in looking at these in the media summit 2 years ago). We didn't have internal pads at the time. > to add binning support to a driver I care about (ov4689), which > presently does not implement any binning configuration at all? Now that you can use internal pads, I would follow what is described in patch 3/4 of this series. Thanks j > > -- > Best regards, > Mikhail >
