radeon: GPU lockup when restarting a video on RV730

Hi,

I am observing issue on video decoding with acceleration enabled, first time a video is played it is displaying fine, then on later attempts player will fallback to un-accelerated rendering (or destroy display or freeze system if not lucky)

To reproduce I am using this loop:

export DISPLAY=:0 ; while true ; do mpv 'http://youtu.be/9J5CHTFWnTc' ; sleep 10 ; done

Then I can observe driver yelling:

[ 99.002309] radeon 0000:01:00.0: ring 5 stalled for more than 10080msec
[ 99.002317] radeon 0000:01:00.0: GPU lockup (current fence id 0x00000000000003fb last fence id 0x00000000000003ff on ring 5)
[ 99.012046] radeon 0000:01:00.0: couldn't schedule ib
[ 99.012107] [drm:radeon_uvd_suspend [radeon]] *ERROR* Error destroying UVD (-22)!
[ 99.028154] radeon 0000:01:00.0: Saved 1433 dwords of commands on ring 0.

You'll see more logs there:

https://launchpadlibrarian.net/502954026/CurrentDmesg.txt

from this related report:

https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1900854

I can join any chatroom if you need me to try more stuff , like a test suite for radeon driver ?