[PATCH 5.4 200/260] drm/etnaviv: put submit prev MMU context when it exists

[Greg Kroah-Hartman]

From: Lucas Stach <l.stach@xxxxxxxxxxxxxx>

commit cda7532916f7bc860b36a1806cb8352e6f63dacb upstream.

The prev context is the MMU context at the time of the job
queueing in hardware. As a job might be queued multiple times
due to recovery after a GPU hang, we need to make sure to put
the stale prev MMU context from a prior queuing, to avoid the
reference and thus the MMU context leaking.

Cc: stable@xxxxxxxxxxxxxxx # 5.4
Signed-off-by: Lucas Stach <l.stach@xxxxxxxxxxxxxx>
Tested-by: Michael Walle <michael@xxxxxxxx>
Tested-by: Marek Vasut <marex@xxxxxxx>
Reviewed-by: Christian Gmeiner <christian.gmeiner@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/gpu/drm/etnaviv/etnaviv_gpu.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
@@ -1310,6 +1310,8 @@ struct dma_fence *etnaviv_gpu_submit(str
 		gpu->mmu_context = etnaviv_iommu_context_get(submit->mmu_context);
 		etnaviv_gpu_start_fe_idleloop(gpu);
 	} else {
+		if (submit->prev_mmu_context)
+			etnaviv_iommu_context_put(submit->prev_mmu_context);
 		submit->prev_mmu_context = etnaviv_iommu_context_get(gpu->mmu_context);
 	}