Hi Hardy Why are you using: result = ioctl(fd, _IOWR('u', 0x20, struct uvc_xu_control_mapping), &mapping); instead of result = ioctl(fd, UVCIOC_CTRL_MAP, &mapping); Can you return the output of: strace -f uvc_xu_v4l_mapping_demo Thanks! On Fri, 28 Apr 2023 at 09:15, hardycheng(鄭易昕) <hardycheng@xxxxxxx> wrote: > > Hi, > > # Environment: > > OS = Ubuntu 22.04 LTS (Linux version 5.19.0-41-generic) > Program Language = C Language > > # Overview: > > We plug in our UVC camera to PC, and try to use `UVCIOC_CTRL_MAP` function on PC to create the v4l2 control mapping, but we got error `UVCIOC_CTRL_MAP: Inappropriate ioctl for device` > Development with `C language` in `Ubuntu 22.04 LTS` > > # Description: > > We have a custom UVC camera and we can modify the extension unit(XU) by ourself. (USB descriptions reference attachments `uvc_xu_descriptor.PNG` & `usb_decriptions.txt`) > > We make sure that UVCIOC_CTRL_QUERY is work to control our XU item (demo code in attachment `uvc_xu_ioctl_demo.c`) > > but UVCIOC_CTRL_MAP function fail with error message `UVCIOC_CTRL_MAP: Inappropriate ioctl for device` (demo code in attachment `uvc_xu_v4l_mapping_demo.c`) > > # Problems: > > 1. Is UVCIOC_CTRL_MAP function using in the PC host? > 2. Can you found any syntax problem in our demo code `uvc_xu_v4l_mapping_demo.c`? > 3. Is there any sample code about struct `uvc_xu_control_mapping` using? > > Looking forward to your reply, > Best Regards, > Hardy#2374 > > *****CONFIDENTIAL INFORMATION***** > > This email is intended only for the use of the person or entity to whom it is > addressed and contains information that may be subject to and/or may be > restricted from disclosure by contract or applicable law. If you are not the > intended recipient of this email, be advised that any disclosure, copy, > distribution or use of the contents of this message is strictly prohibited. > If you are not the intended recipient of this email, please notify the sender > that you have received this in error by replying to this message. Then, > please delete it from your system. Our Privacy Policy is available here > https://www.msi.com/page/privacy-policy. Thank you. -- Ricardo Ribalda