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From: "Nicolai Hähnle" <nhaehnle-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
To: amd-gfx-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org
Cc: "Nicolai Hähnle" <nicolai.haehnle-5C7GfCeVMHo@public.gmane.org>,
	dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org
Subject: [PATCH 2/3] drm/ttm: fix the documentation of ttm_bo_init
Date: Tue, 14 Feb 2017 11:37:43 +0100	[thread overview]
Message-ID: <20170214103744.4133-2-nhaehnle@gmail.com> (raw)
In-Reply-To: <20170214103744.4133-1-nhaehnle-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>

From: Nicolai Hähnle <nicolai.haehnle@amd.com>

As the comment says: callers of ttm_bo_init cannot rely on having the
only reference to the BO when the function returns successfully.

Signed-off-by: Nicolai Hähnle <nicolai.haehnle@amd.com>
---
 include/drm/ttm/ttm_bo_api.h | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h
index d44b8e4..7b2807f 100644
--- a/include/drm/ttm/ttm_bo_api.h
+++ b/include/drm/ttm/ttm_bo_api.h
@@ -521,7 +521,11 @@ extern int ttm_bo_init_top(struct ttm_bo_device *bdev,
  * As this object may be part of a larger structure, this function,
  * together with the @destroy function,
  * enables driver-specific objects derived from a ttm_buffer_object.
- * On successful return, the object kref and list_kref are set to 1.
+ *
+ * On successful return, the caller owns an object kref to @bo. The kref and
+ * list_kref are usually set to 1, but note that in some situations, other
+ * tasks may already be holding references to @bo as well.
+ *
  * If a failure occurs, the function will call the @destroy function, or
  * kfree() if @destroy is NULL. Thus, after a failure, dereferencing @bo is
  * illegal and will likely cause memory corruption.
-- 
2.9.3

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  parent reply	other threads:[~2017-02-14 10:37 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-02-14 10:37 [PATCH 1/3] drm/ttm: split BO structure initialization into a separate function Nicolai Hähnle
     [not found] ` <20170214103744.4133-1-nhaehnle-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2017-02-14 10:37   ` Nicolai Hähnle [this message]
2017-02-14 10:37   ` [PATCH 3/3] drm/amdgpu: fix lock cleanup during buffer creation Nicolai Hähnle
2017-02-15  3:16   ` [PATCH 1/3] drm/ttm: split BO structure initialization into a separate function zhoucm1
     [not found]     ` <58A3C7FE.2080308-5C7GfCeVMHo@public.gmane.org>
2017-02-15 10:43       ` Nicolai Hähnle
     [not found]         ` <403a8be3-7f55-085c-b9ad-19551be33332-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2017-02-15 10:47           ` zhoucm1
2017-02-15 14:05       ` Nicolai Hähnle
2017-02-14 10:49 ` Christian König
     [not found]   ` <b9c665fe-4e9a-7163-aa8a-0c9ce73a78a0-ANTagKRnAhcb1SvskN2V4Q@public.gmane.org>
2017-02-14 12:00     ` Nicolai Hähnle
     [not found]       ` <9229e0d9-4e9d-0233-4ba2-c54c7192acfa-5C7GfCeVMHo@public.gmane.org>
2017-02-14 12:51         ` Christian König
     [not found]           ` <f43631b3-2527-54c1-d0bc-98460772b77b-ANTagKRnAhcb1SvskN2V4Q@public.gmane.org>
2017-02-15 13:35             ` Nicolai Hähnle
     [not found]               ` <06a90674-9f46-e646-9893-8b2748ddd9e4-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2017-02-15 13:54                 ` Nicolai Hähnle

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