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author | Dave Airlie <airlied@redhat.com> | 2017-03-23 08:53:41 +1000 |
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committer | Dave Airlie <airlied@redhat.com> | 2017-03-23 08:53:41 +1000 |
commit | edd849e5448c4f6ddc04a5fa1ac5479176660c27 (patch) | |
tree | 2a055fc27ab9263ba34bef89717b5028f49b0bc2 /Documentation/gpu | |
parent | be5df20a34d78d986ddfb6e0fc87e4fa4d05268b (diff) | |
parent | 62c58af32c935a98a1e8d8ceb39a3a47b36fbbcd (diff) | |
download | linux-edd849e5448c4f6ddc04a5fa1ac5479176660c27.tar.bz2 |
Merge tag 'drm-misc-next-2017-03-21' of git://anongit.freedesktop.org/git/drm-misc into drm-next
drm-misc for 4.12, 2nd attempt this week:
- topic branch from Jon Corbet for the new graph kerneldoc support
- lots of graphs for kms/atomic things using the above
- some vblank query tuning from Chris
- gem/cma_fops macros
- moar docs
Driver stuff:
- vc4 hdmi audio, yay (Eric)
- dw-hdmi polish from a bunch of people
- some rockchip dp updates that didn't make last week (Chris Zhong)
- misc bridge&driver updates
* tag 'drm-misc-next-2017-03-21' of git://anongit.freedesktop.org/git/drm-misc: (37 commits)
drm/edid: detect SCDC support in HF-VSDB
drm/edid: detect SCDC support in HF-VSDB
drm/edid: check for HF-VSDB block
drm: Add SCDC helpers
drm: bridge: dw-hdmi: add HDMI vendor specific infoframe config
drm/bridge: dw_hdmi: support i2c extended read mode
drm/msm: add stubs for msm_{perf,rd}_debugfs_cleanup
drm: bochs: Don't remove uninitialized fbdev framebuffer
drm: vc4: remove redundant check of plane being non-null
drm/vc4: use platform_register_drivers
dma-fence: add dma_fence_match_context helper
drm/vc4: Add HDMI audio support
dt-bindings: Document the dmas and dma-names properties for VC4 HDMI
drm/atmel-hlcdc: Fix suspend/resume implementation
drm: Skip the waitqueue setup for vblank queries
drm: Defer disabling the vblank IRQ until the next interrupt (for instant-off)
drm/doc: atomic overview, with graph
drm/doc: diagram for mode objects and properties
drm/doc: Consistent kerneldoc include order
drm/doc: Add KMS overview graphs
...
Diffstat (limited to 'Documentation/gpu')
-rw-r--r-- | Documentation/gpu/drm-internals.rst | 58 | ||||
-rw-r--r-- | Documentation/gpu/drm-kms-helpers.rst | 40 | ||||
-rw-r--r-- | Documentation/gpu/drm-kms.rst | 264 | ||||
-rw-r--r-- | Documentation/gpu/drm-mm.rst | 24 | ||||
-rw-r--r-- | Documentation/gpu/drm-uapi.rst | 4 |
5 files changed, 301 insertions, 89 deletions
diff --git a/Documentation/gpu/drm-internals.rst b/Documentation/gpu/drm-internals.rst index 3bb4d937cdfe..a09c721f9e89 100644 --- a/Documentation/gpu/drm-internals.rst +++ b/Documentation/gpu/drm-internals.rst @@ -140,12 +140,12 @@ Device Instance and Driver Handling .. kernel-doc:: drivers/gpu/drm/drm_drv.c :doc: driver instance overview -.. kernel-doc:: drivers/gpu/drm/drm_drv.c - :export: - .. kernel-doc:: include/drm/drm_drv.h :internal: +.. kernel-doc:: drivers/gpu/drm/drm_drv.c + :export: + Driver Load ----------- @@ -243,61 +243,15 @@ drivers. Open/Close, File Operations and IOCTLs ====================================== -Open and Close --------------- - -Open and close handlers. None of those methods are mandatory:: - - int (*firstopen) (struct drm_device *); - void (*lastclose) (struct drm_device *); - int (*open) (struct drm_device *, struct drm_file *); - void (*preclose) (struct drm_device *, struct drm_file *); - void (*postclose) (struct drm_device *, struct drm_file *); - -The firstopen method is called by the DRM core for legacy UMS (User Mode -Setting) drivers only when an application opens a device that has no -other opened file handle. UMS drivers can implement it to acquire device -resources. KMS drivers can't use the method and must acquire resources -in the load method instead. - -Similarly the lastclose method is called when the last application -holding a file handle opened on the device closes it, for both UMS and -KMS drivers. Additionally, the method is also called at module unload -time or, for hot-pluggable devices, when the device is unplugged. The -firstopen and lastclose calls can thus be unbalanced. - -The open method is called every time the device is opened by an -application. Drivers can allocate per-file private data in this method -and store them in the struct :c:type:`struct drm_file -<drm_file>` driver_priv field. Note that the open method is -called before firstopen. - -The close operation is split into preclose and postclose methods. -Drivers must stop and cleanup all per-file operations in the preclose -method. For instance pending vertical blanking and page flip events must -be cancelled. No per-file operation is allowed on the file handle after -returning from the preclose method. - -Finally the postclose method is called as the last step of the close -operation, right before calling the lastclose method if no other open -file handle exists for the device. Drivers that have allocated per-file -private data in the open method should free it here. - -The lastclose method should restore CRTC and plane properties to default -value, so that a subsequent open of the device will not inherit state -from the previous user. It can also be used to execute delayed power -switching state changes, e.g. in conjunction with the :ref:`vga_switcheroo` -infrastructure. Beyond that KMS drivers should not do any -further cleanup. Only legacy UMS drivers might need to clean up device -state so that the vga console or an independent fbdev driver could take -over. - File Operations --------------- .. kernel-doc:: drivers/gpu/drm/drm_file.c :doc: file operations +.. kernel-doc:: include/drm/drm_file.h + :internal: + .. kernel-doc:: drivers/gpu/drm/drm_file.c :export: diff --git a/Documentation/gpu/drm-kms-helpers.rst b/Documentation/gpu/drm-kms-helpers.rst index 03040aa14fe8..c075aadd7078 100644 --- a/Documentation/gpu/drm-kms-helpers.rst +++ b/Documentation/gpu/drm-kms-helpers.rst @@ -37,10 +37,12 @@ Modeset Helper Reference for Common Vtables =========================================== .. kernel-doc:: include/drm/drm_modeset_helper_vtables.h - :internal: + :doc: overview .. kernel-doc:: include/drm/drm_modeset_helper_vtables.h - :doc: overview + :internal: + +.. _drm_atomic_helper: Atomic Modeset Helper Functions Reference ========================================= @@ -84,27 +86,27 @@ Legacy CRTC/Modeset Helper Functions Reference Simple KMS Helper Reference =========================== +.. kernel-doc:: drivers/gpu/drm/drm_simple_kms_helper.c + :doc: overview + .. kernel-doc:: include/drm/drm_simple_kms_helper.h :internal: .. kernel-doc:: drivers/gpu/drm/drm_simple_kms_helper.c :export: -.. kernel-doc:: drivers/gpu/drm/drm_simple_kms_helper.c - :doc: overview - fbdev Helper Functions Reference ================================ .. kernel-doc:: drivers/gpu/drm/drm_fb_helper.c :doc: fbdev helpers -.. kernel-doc:: drivers/gpu/drm/drm_fb_helper.c - :export: - .. kernel-doc:: include/drm/drm_fb_helper.h :internal: +.. kernel-doc:: drivers/gpu/drm/drm_fb_helper.c + :export: + Framebuffer CMA Helper Functions Reference ========================================== @@ -114,6 +116,8 @@ Framebuffer CMA Helper Functions Reference .. kernel-doc:: drivers/gpu/drm/drm_fb_cma_helper.c :export: +.. _drm_bridges: + Bridges ======= @@ -139,18 +143,20 @@ Bridge Helper Reference .. kernel-doc:: drivers/gpu/drm/drm_bridge.c :export: +.. _drm_panel_helper: + Panel Helper Reference ====================== +.. kernel-doc:: drivers/gpu/drm/drm_panel.c + :doc: drm panel + .. kernel-doc:: include/drm/drm_panel.h :internal: .. kernel-doc:: drivers/gpu/drm/drm_panel.c :export: -.. kernel-doc:: drivers/gpu/drm/drm_panel.c - :doc: drm panel - Display Port Helper Functions Reference ======================================= @@ -217,6 +223,18 @@ EDID Helper Functions Reference .. kernel-doc:: drivers/gpu/drm/drm_edid.c :export: +SCDC Helper Functions Reference +=============================== + +.. kernel-doc:: drivers/gpu/drm/drm_scdc_helper.c + :doc: scdc helpers + +.. kernel-doc:: include/drm/drm_scdc_helper.h + :internal: + +.. kernel-doc:: drivers/gpu/drm/drm_scdc_helper.c + :export: + Rectangle Utilities Reference ============================= diff --git a/Documentation/gpu/drm-kms.rst b/Documentation/gpu/drm-kms.rst index 4d4068855ec4..bfecd21a8cdf 100644 --- a/Documentation/gpu/drm-kms.rst +++ b/Documentation/gpu/drm-kms.rst @@ -15,35 +15,271 @@ be setup by initializing the following fields. - struct drm_mode_config_funcs \*funcs; Mode setting functions. -Mode Configuration +Overview +======== + +.. kernel-render:: DOT + :alt: KMS Display Pipeline + :caption: KMS Display Pipeline Overview + + digraph "KMS" { + node [shape=box] + + subgraph cluster_static { + style=dashed + label="Static Objects" + + node [bgcolor=grey style=filled] + "drm_plane A" -> "drm_crtc" + "drm_plane B" -> "drm_crtc" + "drm_crtc" -> "drm_encoder A" + "drm_crtc" -> "drm_encoder B" + } + + subgraph cluster_user_created { + style=dashed + label="Userspace-Created" + + node [shape=oval] + "drm_framebuffer 1" -> "drm_plane A" + "drm_framebuffer 2" -> "drm_plane B" + } + + subgraph cluster_connector { + style=dashed + label="Hotpluggable" + + "drm_encoder A" -> "drm_connector A" + "drm_encoder B" -> "drm_connector B" + } + } + +The basic object structure KMS presents to userspace is fairly simple. +Framebuffers (represented by :c:type:`struct drm_framebuffer <drm_framebuffer>`, +see `Frame Buffer Abstraction`_) feed into planes. One or more (or even no) +planes feed their pixel data into a CRTC (represented by :c:type:`struct +drm_crtc <drm_crtc>`, see `CRTC Abstraction`_) for blending. The precise +blending step is explained in more detail in `Plane Composition Properties`_ and +related chapters. + +For the output routing the first step is encoders (represented by +:c:type:`struct drm_encoder <drm_encoder>`, see `Encoder Abstraction`_). Those +are really just internal artifacts of the helper libraries used to implement KMS +drivers. Besides that they make it unecessarily more complicated for userspace +to figure out which connections between a CRTC and a connector are possible, and +what kind of cloning is supported, they serve no purpose in the userspace API. +Unfortunately encoders have been exposed to userspace, hence can't remove them +at this point. Futhermore the exposed restrictions are often wrongly set by +drivers, and in many cases not powerful enough to express the real restrictions. +A CRTC can be connected to multiple encoders, and for an active CRTC there must +be at least one encoder. + +The final, and real, endpoint in the display chain is the connector (represented +by :c:type:`struct drm_connector <drm_connector>`, see `Connector +Abstraction`_). Connectors can have different possible encoders, but the kernel +driver selects which encoder to use for each connector. The use case is DVI, +which could switch between an analog and a digital encoder. Encoders can also +drive multiple different connectors. There is exactly one active connector for +every active encoder. + +Internally the output pipeline is a bit more complex and matches today's +hardware more closely: + +.. kernel-render:: DOT + :alt: KMS Output Pipeline + :caption: KMS Output Pipeline + + digraph "Output Pipeline" { + node [shape=box] + + subgraph { + "drm_crtc" [bgcolor=grey style=filled] + } + + subgraph cluster_internal { + style=dashed + label="Internal Pipeline" + { + node [bgcolor=grey style=filled] + "drm_encoder A"; + "drm_encoder B"; + "drm_encoder C"; + } + + { + node [bgcolor=grey style=filled] + "drm_encoder B" -> "drm_bridge B" + "drm_encoder C" -> "drm_bridge C1" + "drm_bridge C1" -> "drm_bridge C2"; + } + } + + "drm_crtc" -> "drm_encoder A" + "drm_crtc" -> "drm_encoder B" + "drm_crtc" -> "drm_encoder C" + + + subgraph cluster_output { + style=dashed + label="Outputs" + + "drm_encoder A" -> "drm_connector A"; + "drm_bridge B" -> "drm_connector B"; + "drm_bridge C2" -> "drm_connector C"; + + "drm_panel" + } + } + +Internally two additional helper objects come into play. First, to be able to +share code for encoders (sometimes on the same SoC, sometimes off-chip) one or +more :ref:`drm_bridges` (represented by :c:type:`struct drm_bridge +<drm_bridge>`) can be linked to an encoder. This link is static and cannot be +changed, which means the cross-bar (if there is any) needs to be mapped between +the CRTC and any encoders. Often for drivers with bridges there's no code left +at the encoder level. Atomic drivers can leave out all the encoder callbacks to +essentially only leave a dummy routing object behind, which is needed for +backwards compatibility since encoders are exposed to userspace. + +The second object is for panels, represented by :c:type:`struct drm_panel +<drm_panel>`, see :ref:`drm_panel_helper`. Panels do not have a fixed binding +point, but are generally linked to the driver private structure that embeds +:c:type:`struct drm_connector <drm_connector>`. + +Note that currently the bridge chaining and interactions with connectors and +panels are still in-flux and not really fully sorted out yet. KMS Core Structures and Functions ================================= -.. kernel-doc:: drivers/gpu/drm/drm_mode_config.c - :export: - .. kernel-doc:: include/drm/drm_mode_config.h :internal: +.. kernel-doc:: drivers/gpu/drm/drm_mode_config.c + :export: + Modeset Base Object Abstraction =============================== +.. kernel-render:: DOT + :alt: Mode Objects and Properties + :caption: Mode Objects and Properties + + digraph { + node [shape=box] + + "drm_property A" -> "drm_mode_object A" + "drm_property A" -> "drm_mode_object B" + "drm_property B" -> "drm_mode_object A" + } + +The base structure for all KMS objects is :c:type:`struct drm_mode_object +<drm_mode_object>`. One of the base services it provides is tracking properties, +which are especially important for the atomic IOCTL (see `Atomic Mode +Setting`_). The somewhat surprising part here is that properties are not +directly instantiated on each object, but free-standing mode objects themselves, +represented by :c:type:`struct drm_property <drm_property>`, which only specify +the type and value range of a property. Any given property can be attached +multiple times to different objects using :c:func:`drm_object_attach_property() +<drm_object_attach_property>`. + .. kernel-doc:: include/drm/drm_mode_object.h :internal: .. kernel-doc:: drivers/gpu/drm/drm_mode_object.c :export: -Atomic Mode Setting Function Reference -====================================== +Atomic Mode Setting +=================== -.. kernel-doc:: drivers/gpu/drm/drm_atomic.c - :export: + +.. kernel-render:: DOT + :alt: Mode Objects and Properties + :caption: Mode Objects and Properties + + digraph { + node [shape=box] + + subgraph cluster_state { + style=dashed + label="Free-standing state" + + "drm_atomic_state" -> "duplicated drm_plane_state A" + "drm_atomic_state" -> "duplicated drm_plane_state B" + "drm_atomic_state" -> "duplicated drm_crtc_state" + "drm_atomic_state" -> "duplicated drm_connector_state" + "drm_atomic_state" -> "duplicated driver private state" + } + + subgraph cluster_current { + style=dashed + label="Current state" + + "drm_device" -> "drm_plane A" + "drm_device" -> "drm_plane B" + "drm_device" -> "drm_crtc" + "drm_device" -> "drm_connector" + "drm_device" -> "driver private object" + + "drm_plane A" -> "drm_plane_state A" + "drm_plane B" -> "drm_plane_state B" + "drm_crtc" -> "drm_crtc_state" + "drm_connector" -> "drm_connector_state" + "driver private object" -> "driver private state" + } + + "drm_atomic_state" -> "drm_device" [label="atomic_commit"] + "duplicated drm_plane_state A" -> "drm_device"[style=invis] + } + +Atomic provides transactional modeset (including planes) updates, but a +bit differently from the usual transactional approach of try-commit and +rollback: + +- Firstly, no hardware changes are allowed when the commit would fail. This + allows us to implement the DRM_MODE_ATOMIC_TEST_ONLY mode, which allows + userspace to explore whether certain configurations would work or not. + +- This would still allow setting and rollback of just the software state, + simplifying conversion of existing drivers. But auditing drivers for + correctness of the atomic_check code becomes really hard with that: Rolling + back changes in data structures all over the place is hard to get right. + +- Lastly, for backwards compatibility and to support all use-cases, atomic + updates need to be incremental and be able to execute in parallel. Hardware + doesn't always allow it, but where possible plane updates on different CRTCs + should not interfere, and not get stalled due to output routing changing on + different CRTCs. + +Taken all together there's two consequences for the atomic design: + +- The overall state is split up into per-object state structures: + :c:type:`struct drm_plane_state <drm_plane_state>` for planes, :c:type:`struct + drm_crtc_state <drm_crtc_state>` for CRTCs and :c:type:`struct + drm_connector_state <drm_connector_state>` for connectors. These are the only + objects with userspace-visible and settable state. For internal state drivers + can subclass these structures through embeddeding, or add entirely new state + structures for their globally shared hardware functions. + +- An atomic update is assembled and validated as an entirely free-standing pile + of structures within the :c:type:`drm_atomic_state <drm_atomic_state>` + container. Again drivers can subclass that container for their own state + structure tracking needs. Only when a state is committed is it applied to the + driver and modeset objects. This way rolling back an update boils down to + releasing memory and unreferencing objects like framebuffers. + +Read on in this chapter, and also in :ref:`drm_atomic_helper` for more detailed +coverage of specific topics. + +Atomic Mode Setting Function Reference +-------------------------------------- .. kernel-doc:: include/drm/drm_atomic.h :internal: +.. kernel-doc:: drivers/gpu/drm/drm_atomic.c + :export: + CRTC Abstraction ================ @@ -68,12 +304,12 @@ Frame Buffer Abstraction Frame Buffer Functions Reference -------------------------------- -.. kernel-doc:: drivers/gpu/drm/drm_framebuffer.c - :export: - .. kernel-doc:: include/drm/drm_framebuffer.h :internal: +.. kernel-doc:: drivers/gpu/drm/drm_framebuffer.c + :export: + DRM Format Handling =================== @@ -376,8 +612,8 @@ operation handler. Vertical Blanking and Interrupt Handling Functions Reference ------------------------------------------------------------ -.. kernel-doc:: drivers/gpu/drm/drm_irq.c - :export: - .. kernel-doc:: include/drm/drm_irq.h :internal: + +.. kernel-doc:: drivers/gpu/drm/drm_irq.c + :export: diff --git a/Documentation/gpu/drm-mm.rst b/Documentation/gpu/drm-mm.rst index d7a29d41789f..96b9c34c21e4 100644 --- a/Documentation/gpu/drm-mm.rst +++ b/Documentation/gpu/drm-mm.rst @@ -365,36 +365,36 @@ from the client in libdrm. GEM Function Reference ---------------------- -.. kernel-doc:: drivers/gpu/drm/drm_gem.c - :export: - .. kernel-doc:: include/drm/drm_gem.h :internal: +.. kernel-doc:: drivers/gpu/drm/drm_gem.c + :export: + GEM CMA Helper Functions Reference ---------------------------------- .. kernel-doc:: drivers/gpu/drm/drm_gem_cma_helper.c :doc: cma helpers -.. kernel-doc:: drivers/gpu/drm/drm_gem_cma_helper.c - :export: - .. kernel-doc:: include/drm/drm_gem_cma_helper.h :internal: +.. kernel-doc:: drivers/gpu/drm/drm_gem_cma_helper.c + :export: + VMA Offset Manager ================== .. kernel-doc:: drivers/gpu/drm/drm_vma_manager.c :doc: vma offset manager -.. kernel-doc:: drivers/gpu/drm/drm_vma_manager.c - :export: - .. kernel-doc:: include/drm/drm_vma_manager.h :internal: +.. kernel-doc:: drivers/gpu/drm/drm_vma_manager.c + :export: + PRIME Buffer Sharing ==================== @@ -473,12 +473,12 @@ LRU Scan/Eviction Support DRM MM Range Allocator Function References ------------------------------------------ -.. kernel-doc:: drivers/gpu/drm/drm_mm.c - :export: - .. kernel-doc:: include/drm/drm_mm.h :internal: +.. kernel-doc:: drivers/gpu/drm/drm_mm.c + :export: + DRM Cache Handling ================== diff --git a/Documentation/gpu/drm-uapi.rst b/Documentation/gpu/drm-uapi.rst index fcc228ef5bc4..352652810dab 100644 --- a/Documentation/gpu/drm-uapi.rst +++ b/Documentation/gpu/drm-uapi.rst @@ -21,6 +21,8 @@ libdrm Device Lookup :doc: getunique and setversion story +.. _drm_primary_node: + Primary Nodes, DRM Master and Authentication ============================================ @@ -103,6 +105,8 @@ is already rather painful for the DRM subsystem, with multiple different uAPIs for the same thing co-existing. If we add a few more complete mistakes into the mix every year it would be entirely unmanageable. +.. _drm_render_node: + Render nodes ============ |