FAILED: patch "[PATCH] drm/ttm: fix leaking fences via ttm_buffer_object_transfer" failed to apply to 5.4-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 8c8c06207bcfc5a7e5918fc0a0f7f7b9a2e196d6 Mon Sep 17 00:00:00 2001
From: Ahzo <Ahzo@tutanota.com>
Date: Tue, 25 Feb 2020 13:56:14 -0500
Subject: [PATCH] drm/ttm: fix leaking fences via ttm_buffer_object_transfer
MIME-Version: 1.0
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Set the drm_device to NULL, so that the newly created buffer object
doesn't appear to use the embedded gem object.

This is necessary, because otherwise no corresponding dma_resv_fini for
the dma_resv_init is called, resulting in a memory leak.

The dma_resv_fini in ttm_bo_release_list is only called if the embedded
gem object is not used, which is determined by checking if the
drm_device is NULL.

Bug: https://gitlab.freedesktop.org/drm/amd/issues/958
Fixes: 1e053b10ba60 ("drm/ttm: use gem reservation object")
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Ahzo <Ahzo@tutanota.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/355089/

diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
index 49ed55779128..953c82a4f573 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_util.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
@@ -515,6 +515,7 @@ static int ttm_buffer_object_transfer(struct ttm_buffer_object *bo,
 		fbo->base.base.resv = &fbo->base.base._resv;
 
 	dma_resv_init(&fbo->base.base._resv);
+	fbo->base.base.dev = NULL;
 	ret = dma_resv_trylock(&fbo->base.base._resv);
 	WARN_ON(!ret);