kern/56115: uvideo does not work on rpi4

[sc.dying%gmail.com@localhost]

>Number:         56115
>Category:       kern
>Synopsis:       uvideo does not work on rpi4
>Confidential:   no
>Severity:       critical
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Apr 18 12:20:00 +0000 2021
>Originator:     sc.dying%gmail.com@localhost
>Release:        NetBSD-current 9.99.81
>Organization:
>Environment:
System: NetBSD  9.99.81 NetBSD 9.99.81 (GENERIC64) #0: Sat Apr 10 04:10:21 UTC 2021  mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/evbarm/compile/GENERIC64 evbarm aarch64
Architecture: aarch64
Machine: evbarm
>Description:

My webcams that work on NetBSD-current/amd64 with Intel chipset
do not work on rpi4. mplayer shows simple black window.

% mplayer tv://
[...]
Audio: no sound
Starting playback...
v4l2: select timeout
v4l2: select timeout
v4l2: select timeout
v4l2: select timeout
v4l2: select timeout
v4l2: select timeout
v4l2: select timeout

>How-To-Repeat:

Install NetBSD-current/evbarm-aarch64 on Rpi4,
install multimedia/mplayer,
connect webcam which supports UVC protocol,
and run mplayer tv://.

>Fix:

Yes, please.