From: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
[ Upstream commit b4fb748f0b734ce1d2e7834998cc599fcbd25d67 ]
Quoting Yassine: ring->memptrs->rptr is never updated and stays 0, so
the comparison always evaluates to false and get_next_ring always
returns ring 0 thinking it isn't empty.
Fix this by calling get_rptr() instead of reading rptr directly.
Reported-by: Yassine Oudjana <y.oudjana@xxxxxxxxxxxxxx>
Fixes: b1fc2839d2f9 ("drm/msm: Implement preemption for A5XX targets")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
Patchwork: https://patchwork.freedesktop.org/patch/522642/
Link: https://lore.kernel.org/r/20230214020956.164473-4-dmitry.baryshkov@xxxxxxxxxx
Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/gpu/drm/msm/adreno/a5xx_preempt.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/msm/adreno/a5xx_preempt.c b/drivers/gpu/drm/msm/adreno/a5xx_preempt.c
index 8abc9a2b114a2..6e326d851ba53 100644
--- a/drivers/gpu/drm/msm/adreno/a5xx_preempt.c
+++ b/drivers/gpu/drm/msm/adreno/a5xx_preempt.c
@@ -63,7 +63,7 @@ static struct msm_ringbuffer *get_next_ring(struct msm_gpu *gpu)
struct msm_ringbuffer *ring = gpu->rb[i];
spin_lock_irqsave(&ring->preempt_lock, flags);
- empty = (get_wptr(ring) == ring->memptrs->rptr);
+ empty = (get_wptr(ring) == gpu->funcs->get_rptr(gpu, ring));
spin_unlock_irqrestore(&ring->preempt_lock, flags);
if (!empty)
--
2.39.2
