NVMAP_IOC_FREE failed: Bad file descriptor

Autonomous Machines Jetson & Embedded Systems Jetson Nano
1

NvV4l2ElementPlane never calls v4l2_close() on buffers exported with VIDIOC_EXPBUF.
It’s quite unusual. I mean if I call open() I’m supposed to call close() later.

[url]https://www.linuxtv.org/downloads/v4l-dvb-apis-old/vidioc-expbuf.html[/url]
“It is recommended to close a DMABUF file when it is no longer used to allow the associated memory to be reclaimed.”

I thought it’s a leak initially but if I close exported buffers I get one error message per buffer eventually:
NVMAP_IOC_FREE failed: Bad file descriptor

Could somebody confirm that exported MM buffers must not be closed?
I’m doublechecking, because, again, it’s quite unusual.

2

Hi,
On Nano, DMABUF is NvBuffer and we use APIs in nvbuf_utils.h to create and destroy buffers. We have implemented classes to run hardware acceleration in tegra_multimedia_api\samples\common\classes. Suggest you use the implementation.