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 ...
2017-03-23 08:53:41 +10:00
parent be5df20a34 62c58af32c
commit edd849e544
67 changed files with 2771 additions and 484 deletions
@@ -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:

@@ -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
 =============================

@@ -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:
@@ -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
 ==================

@@ -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
 ============