Re: [PATCH v8 0/4] usb: gadget: uvc: use configfs entries for negotiation and v4l2 VIDIOCS

[Greg KH <gregkh@linuxfoundation.org>]

On Wed, Sep 07, 2022 at 04:02:50PM +0200, Michael Grzeschik wrote:
> This series improves the uvc video gadget by parsing the configfs
> entries. With the configfs data, the driver now is able to negotiate the
> format with the usb host in the kernel and also exports the supported
> frames/formats/intervals via the v4l2 VIDIOC interface.
> 
> The uvc userspace stack is also under development. One example is an generic
> v4l2uvcsink gstreamer elemnt, which is currently under discussion. [1]
> 
> [1] https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1304
> 
> With the libusbgx library [1] used by the gadget-tool [2] it is now also
> possible to fully describe the configfs layout of the uvc gadget with scheme
> files.
> 
> [2] https://github.com/linux-usb-gadgets/libusbgx/pull/61/commits/53231c76f9d512f59fdc23b65cd5c46b7fb09eb4
> 
> [3] https://github.com/linux-usb-gadgets/gt/tree/master/examples/systemd
> 
> The bigger picture of these patches is to provide a more versatile interface to
> the uvc gadget. The goal is to simply start a uvc-gadget with the following
> commands:
> 
> $ gt load uvc.scheme
> $ gst-launch v4l2src ! v4l2uvcsink
> 
> --
> 
> v1: https://lore.kernel.org/linux-usb/20210530222239.8793-1-m.grzeschik@pengutronix.de/
> v2: https://lore.kernel.org/linux-usb/20211117004432.3763306-1-m.grzeschik@pengutronix.de/
> v3: https://lore.kernel.org/linux-usb/20211117122435.2409362-1-m.grzeschik@pengutronix.de/
> v4: https://lore.kernel.org/linux-usb/20211205225803.268492-1-m.grzeschik@pengutronix.de/
> v5: https://lore.kernel.org/linux-usb/20211209084322.2662616-1-m.grzeschik@pengutronix.de/
> v6: https://lore.kernel.org/linux-usb/20220105115527.3592860-1-m.grzeschik@pengutronix.de/
> v7: https://lore.kernel.org/linux-usb/20220608105748.139922-1-m.grzeschik@pengutronix.de/

Please say what changed somewhere :(

Anyway, this patch series does not even build properly:

drivers/usb/gadget/function/uvc_v4l2.c: In function ‘uvc_v4l2_get_format’:
drivers/usb/gadget/function/uvc_v4l2.c:258:42: error: ‘struct uvc_video’ has no member named ‘bpp’
  258 |         fmt->fmt.pix.bytesperline = video->bpp * video->width / 8;
      |                                          ^~
drivers/usb/gadget/function/uvc_v4l2.c:258:55: error: ‘struct uvc_video’ has no member named ‘width’
  258 |         fmt->fmt.pix.bytesperline = video->bpp * video->width / 8;
      |                                                       ^~
drivers/usb/gadget/function/uvc_v4l2.c:259:39: error: ‘struct uvc_video’ has no member named ‘imagesize’
  259 |         fmt->fmt.pix.sizeimage = video->imagesize;
      |                                       ^~
drivers/usb/gadget/function/uvc_v4l2.c: In function ‘uvc_v4l2_try_format’:
drivers/usb/gadget/function/uvc_v4l2.c:316:37: error: ‘bpl’ undeclared (first use in this function)
  316 |         fmt->fmt.pix.bytesperline = bpl;
      |                                     ^~~
drivers/usb/gadget/function/uvc_v4l2.c:316:37: note: each undeclared identifier is reported only once for each function it appears in
drivers/usb/gadget/function/uvc_v4l2.c:317:34: error: ‘imagesize’ undeclared (first use in this function); did you mean ‘page_size’?
  317 |         fmt->fmt.pix.sizeimage = imagesize;
      |                                  ^~~~~~~~~
      |                                  page_size


What did you test this with?

thanks,

greg k-h