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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Lucas Stach <l.stach@pengutronix.de>,
        Michael Walle <michael@walle.cc>, Marek Vasut <marex@denx.de>,
        Christian Gmeiner <christian.gmeiner@gmail.com>
Subject: [PATCH 5.14 025/168] drm/etnaviv: put submit prev MMU context when it exists
Date:   Mon, 20 Sep 2021 18:42:43 +0200
Message-Id: <20210920163922.474363483@linuxfoundation.org>
In-Reply-To: <20210920163921.633181900@linuxfoundation.org>
References: <20210920163921.633181900@linuxfoundation.org>
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From: Lucas Stach <l.stach@pengutronix.de>

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@vger.kernel.org # 5.4
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Tested-by: Michael Walle <michael@walle.cc>
Tested-by: Marek Vasut <marex@denx.de>
Reviewed-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 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
@@ -1368,6 +1368,8 @@ 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);
 	}