drm/msm: a5xx: Make preemption reset case reentrant

nr_rings is reset to 1, but when this function is called for a second
(and third!) time nr_rings > 1 is false, thus the else case is entered
to set up a buffer for the RPTR shadow and consequently written to
RB_RPTR_ADDR, hanging platforms without WHERE_AM_I firmware support.

Restructure the condition in such a way that shadow buffer setup only
ever happens when has_whereami is true; otherwise preemption is only
finalized when the number of ring buffers has not been reset to 1 yet.

Fixes: 8907afb476ac ("drm/msm: Allow a5xx to mark the RPTR shadow as privileged")
Signed-off-by: Marijn Suijten <[email protected]>
Tested-by: AngeloGioacchino Del Regno <[email protected]>
Reviewed-by: Jordan Crouse <[email protected]>
Signed-off-by: Rob Clark <[email protected]>

0 files changed, 0 insertions, 0 deletions