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authorDaniel Vetter <daniel.vetter@ffwll.ch>2016-11-14 12:58:21 +0100
committerDaniel Vetter <daniel.vetter@ffwll.ch>2016-11-15 12:51:49 +0100
commit4f93624ee7c05d5a8da77934a8a9e0e64e121ae6 (patch)
tree03ae98699e66ffea92ec76203b19f2becbab9cd1 /Documentation
parent6c4789edc55d5a0acefc85380d7a3f7c4f21c7cd (diff)
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drm: Consolidate dumb buffer docs
Put the callback docs into struct drm_driver, and the small overview into a DOC comment. Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20161114115825.22050-7-daniel.vetter@ffwll.ch
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/gpu/drm-kms.rst42
1 files changed, 2 insertions, 40 deletions
diff --git a/Documentation/gpu/drm-kms.rst b/Documentation/gpu/drm-kms.rst
index cb0d3537b705..4edfb6d91250 100644
--- a/Documentation/gpu/drm-kms.rst
+++ b/Documentation/gpu/drm-kms.rst
@@ -72,46 +72,8 @@ DRM Format Handling
Dumb Buffer Objects
===================
-The KMS API doesn't standardize backing storage object creation and
-leaves it to driver-specific ioctls. Furthermore actually creating a
-buffer object even for GEM-based drivers is done through a
-driver-specific ioctl - GEM only has a common userspace interface for
-sharing and destroying objects. While not an issue for full-fledged
-graphics stacks that include device-specific userspace components (in
-libdrm for instance), this limit makes DRM-based early boot graphics
-unnecessarily complex.
-
-Dumb objects partly alleviate the problem by providing a standard API to
-create dumb buffers suitable for scanout, which can then be used to
-create KMS frame buffers.
-
-To support dumb objects drivers must implement the dumb_create,
-dumb_destroy and dumb_map_offset operations.
-
-- int (\*dumb_create)(struct drm_file \*file_priv, struct
- drm_device \*dev, struct drm_mode_create_dumb \*args);
- The dumb_create operation creates a driver object (GEM or TTM
- handle) suitable for scanout based on the width, height and depth
- from the struct :c:type:`struct drm_mode_create_dumb
- <drm_mode_create_dumb>` argument. It fills the argument's
- handle, pitch and size fields with a handle for the newly created
- object and its line pitch and size in bytes.
-
-- int (\*dumb_destroy)(struct drm_file \*file_priv, struct
- drm_device \*dev, uint32_t handle);
- The dumb_destroy operation destroys a dumb object created by
- dumb_create.
-
-- int (\*dumb_map_offset)(struct drm_file \*file_priv, struct
- drm_device \*dev, uint32_t handle, uint64_t \*offset);
- The dumb_map_offset operation associates an mmap fake offset with
- the object given by the handle and returns it. Drivers must use the
- :c:func:`drm_gem_create_mmap_offset()` function to associate
- the fake offset as described in ?.
-
-Note that dumb objects may not be used for gpu acceleration, as has been
-attempted on some ARM embedded platforms. Such drivers really must have
-a hardware-specific ioctl to allocate suitable buffer objects.
+.. kernel-doc:: drivers/gpu/drm/drm_dumb_buffers.c
+ :doc: overview
Plane Abstraction
=================