kern/59491: drm permissions issue noticable with mpv -vo drm

[nathanialsloss%yahoo.com.au@localhost]

>Number:         59491
>Category:       kern
>Synopsis:       drm permissions issue noticable with mpv -vo drm
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Jun 29 00:05:01 +0000 2025
>Originator:     Nat Sloss
>Release:        NetBSD-current 10.99.14
>Organization:
>Environment:
NetBSD animal 10.99.14 NetBSD 10.99.14 (GENERIC) #1: Sat Jun 28 23:21:59 AEST 2025  build@microrusty:/home/build/nbsd999-x86_64/sys/arch/amd64/compile/GENERIC amd64

>Description:
The -vo drm switch for mpv does not work it used to work under 9.99.

It errors out like this:
[vo/drm/drm] VT_GETMODE failed: Inappropriate ioctl for device
[vo/drm/drm] Failed to set up VT switcher. Terminal switching will be unavailable.
[vo/drm/drm] Failed to acquire DRM master: Permission denied
[vo/drm/drm] Failed to commit ModeSetting atomic request: Permission denied
[vo/drm] Failed to set CRTC for connector 76: Permission denied
[vo/drm/drm] Failed to commit ModeSetting atomic request: Permission denied
[vo/drm/drm] Failed to restore previous mode
[vo/drm/drm] Failed to drop DRM master: Permission denied
Error opening/initializing the selected video_out (--vo) device.


The permissions on /dev/dri/card0 and /dev/pci0 are as follows:

crw-rw-rw-  1 root  wheel  83, 0 Jul 22  2012 /dev/pci0

[nat@animal:/home/nat]$ls -lh /dev/dri/
total 0B
crw-rw-rw-  1 root  users  180, 0 Jun 29 00:48 card0


note the is no /dev/dri/render* device - i don't know if one is needed or its device node numbers so i can create it.


>How-To-Repeat:
Try mpv -vo drm ./file.mp4 and see there is no video output.
>Fix:
Not known.