drm/etnaviv: put submit prev MMU context when it exists

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: [email protected] # 5.4
Signed-off-by: Lucas Stach <[email protected]>
Tested-by: Michael Walle <[email protected]>
Tested-by: Marek Vasut <[email protected]>
Reviewed-by: Christian Gmeiner <[email protected]>

Author: lynxeye-dev

drivers/gpu/drm/etnaviv/etnaviv_gpu.c

@@ -1374,6 +1374,8 @@ struct dma_fence *etnaviv_gpu_submit(struct etnaviv_gem_submit *submit)
 		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);
 	}