Starting a pipeline: Device or resource busy

[albossard]

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Required Info
Camera Model	D435
Firmware Version	05.12.03.00
Operating System & Version	Linux (Ubuntu 18.04)
Kernel Version (Linux Only)	5.3
Platform	PC
SDK Version	2.32.1
Language	C++
Segment	Robot

Issue Description

Hi, I am a new user of the Realsense D435. When I try to start a pipeline, I get the following error message:

terminate called after throwing an instance of 'rs2::backend_error'
  what():  xioctl(VIDIOC_S_FMT) failed Last Error: Device or resource busy

It is really the .start that causes this. When that line is commented out, there is no error. I am not connecting multiple devices and I do not run another application at the same time. I saw a similar issue where the kernel version seemed to be the root of the problem, but as far as I know 5.3 is supported. What am I not seeing? Also, I sometimes have connection issues and have to unplug the camera so it works again. I am using the standard cable that was delivered with the camera and it is connected to a USB 3.0 hub. It is possible that these issues have nothing to do with each other but thought I'd mention it just in case. The message I get is as follows:

23/03 17:47:56,873 WARNING [140307517556480] (backend-v4l2.h:203) xioctl(VIDIOC_QBUF) re-deque succeeded for fd 20 23/03 17:47:56,873 ERROR [140307517556480] (backend-v4l2.h:196) xioctl(VIDIOC_QBUF) guard failed for fd 20

[DeramOfTheLater]

May I ask how you solved this problem