Hello Alex,

Thanks for replying to my bug report.

I am not certain exactly when this bug was introduced or even which component
is involved, but since TF2 was stable a month ago it must be a regression.

I can report that having played well over 2 h with dynamic power management
disabled, that this bug is related to dpm.

However, playing with radeon.dpm=1 and setting
/sys/class/drm/card0/device/power_dpm_state to 'balanced' (down from
'performance'), the stalls become much less frequent, more in the range of once
or twice every 2-3 hours.