$ xrandr --listproviders
Providers: number : 2
Provider 0: id: 0x45 cap: 0xf, Source Output, Sink Output, Source Offload, Sink Offload crtcs: 3 outputs: 4 associated providers: 0 name:modesetting
Provider 1: id: 0xb0 cap: 0x0 crtcs: 0 outputs: 0 associated providers: 0 name:modesetting
$ xrandr --setprovideroffloadsink 1 0
X Error of failed request: BadValue (integer parameter out of range for operation)
Major opcode of failed request: 140 (RANDR)
Minor opcode of failed request: 34 (RRSetProviderOffloadSink)
Value in failed request: 0xb0
Serial number of failed request: 16
Current serial number in output stream: 17
$ DRI_PRIME=1 glxinfo | grep "OpenGL renderer"
OpenGL renderer string: AMD Radeon R5 M255 (radeonsi, iceland, ACO, DRM 3.61, 6.12.36-1-lts)