Re: [PATCH] usb: gadget: uvc: Make bmControls attr read/write

[Greg KH <gregkh@linuxfoundation.org>]

On Tue, Jan 31, 2023 at 09:57:38AM +0000, Daniel Scally wrote:
> For the Processing Unit and Camera Terminal descriptors defined in
> the UVC Gadget we currently hard-code values into their bmControls
> fields, which enumerates the controls the gadget is able to
> support. This isn't appropriate since only the userspace companion
> program to the kernel driver will know which controls are supported.
> Make the configfs attributes that point to those fields read/write
> so userspace can set them to appropriate values.
> 
> Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com>
> ---
> 
> This patch depends on "usb: gadget: uvc: Generalise helper functions for reuse"
> from my recent series:
> 
> https://lore.kernel.org/linux-usb/20230130093443.25644-3-dan.scally@ideasonboard.com/T/#u

Odd, I think I have that in my tree, yet this fails to build with:

  CALL    scripts/checksyscalls.sh
  CC [M]  drivers/usb/gadget/function/uvc_configfs.o
drivers/usb/gadget/function/uvc_configfs.c: In function ‘uvcg_default_processing_bm_controls_store’:
drivers/usb/gadget/function/uvc_configfs.c:295:15: error: implicit declaration of function ‘__uvcg_iter_item_entries’ [-Werror=implicit-function-declaration]
  295 |         ret = __uvcg_iter_item_entries(page, len, __uvcg_count_item_entries, &n,
      |               ^~~~~~~~~~~~~~~~~~~~~~~~
drivers/usb/gadget/function/uvc_configfs.c:295:51: error: ‘__uvcg_count_item_entries’ undeclared (first use in this function)
  295 |         ret = __uvcg_iter_item_entries(page, len, __uvcg_count_item_entries, &n,
      |                                                   ^~~~~~~~~~~~~~~~~~~~~~~~~
drivers/usb/gadget/function/uvc_configfs.c:295:51: note: each undeclared identifier is reported only once for each function it appears in
drivers/usb/gadget/function/uvc_configfs.c:311:51: error: ‘__uvcg_fill_item_entries’ undeclared (first use in this function)
  311 |         ret = __uvcg_iter_item_entries(page, len, __uvcg_fill_item_entries, &tmp,
      |                                                   ^~~~~~~~~~~~~~~~~~~~~~~~
drivers/usb/gadget/function/uvc_configfs.c: In function ‘uvcg_default_camera_bm_controls_store’:
drivers/usb/gadget/function/uvc_configfs.c:465:51: error: ‘__uvcg_count_item_entries’ undeclared (first use in this function)
  465 |         ret = __uvcg_iter_item_entries(page, len, __uvcg_count_item_entries, &n,
      |                                                   ^~~~~~~~~~~~~~~~~~~~~~~~~
drivers/usb/gadget/function/uvc_configfs.c:481:51: error: ‘__uvcg_fill_item_entries’ undeclared (first use in this function)
  481 |         ret = __uvcg_iter_item_entries(page, len, __uvcg_fill_item_entries, &tmp,
      |                                                   ^~~~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors

What did I do wrong?

thanks,

greg k-h