On Tue, Jul 08, 2025 at 08:28:21AM +0200, Ricardo Ribalda wrote: > On Tue, 1 Jul 2025 at 13:20, Ricardo Ribalda wrote: > > On Sun, 29 Jun 2025 at 20:06, Laurent Pinchart wrote: > > > Hi Ricardo, > > > > > > Thank you for the patch. > > > > > > I would use "software entities" and not "virtual entities" in the > > > subject line and everywhere else, as those entities are not virtual. > > > > > > On Thu, Jun 05, 2025 at 05:53:05PM +0000, Ricardo Ribalda wrote: > > > > Neither the GPIO nor the SWENTITY entities form part of the device > > > > pipeline. We just create them to hold emulated uvc controls. > > > > > > > > When the device initializes, a warning is thrown by the v4l2 core: > > > > uvcvideo 1-1:1.0: Entity type for entity SWENTITY was not initialized! > > > > > > > > There are no entity function that matches what we are doing here, and > > > > it does not make to much sense to create a function for entities that > > > > do not really exist. > > > > > > I don't agree with this. The purpose of reporting entities to userspace > > > through the MC API is to let application enumerate what entities a > > > device contains. Being able to enumerate software entities seems as > > > useful as being able to enumerate hardware entities. > > > > What function shall we use in this case? Nothing here seems to match a > > software entity > > https://www.kernel.org/doc/html/latest/userspace-api/media/mediactl/media-types.html > > > > Any suggestion for name? > > Shall we just live with the warning in dmesg? > > I just realised that if/when we move to the control framework, the > software entity will be gone.... So to avoid introducing a uAPI change > that will be reverted later I think that we should keep this patch. You know my opinion about moving to the control framework, so that's not a very compelling argument :-) We could use MEDIA_ENT_F_PROC_VIDEO_PIXEL_FORMATTER, as that's the function already used by XUs, and the SWENTITY fulfills the same role as XUs in some devices. > > > > Do not create MC entities for them and pretend nothing happened here. > > > > > > > > Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx> > > > > --- > > > > drivers/media/usb/uvc/uvc_entity.c | 10 ++++++++++ > > > > 1 file changed, 10 insertions(+) > > > > > > > > diff --git a/drivers/media/usb/uvc/uvc_entity.c b/drivers/media/usb/uvc/uvc_entity.c > > > > index d1a652ef35ec34801bd39a5124b834edf838a79e..2dbeb4ab0c4c8cc763ff2dcd2d836a50f3c6a040 100644 > > > > --- a/drivers/media/usb/uvc/uvc_entity.c > > > > +++ b/drivers/media/usb/uvc/uvc_entity.c > > > > @@ -72,6 +72,16 @@ static int uvc_mc_init_entity(struct uvc_video_chain *chain, > > > > { > > > > int ret; > > > > > > > > + /* > > > > + * Do not initialize virtual entities, they do not really exist > > > > + * and are not connected to any other entities. > > > > + */ > > > > + switch (UVC_ENTITY_TYPE(entity)) { > > > > + case UVC_EXT_GPIO_UNIT: > > > > + case UVC_SWENTITY_UNIT: > > > > + return 0; > > > > + } > > > > + > > > > if (UVC_ENTITY_TYPE(entity) != UVC_TT_STREAMING) { > > > > u32 function; > > > > -- Regards, Laurent Pinchart
