diff options
Diffstat (limited to 'Documentation/gpu')
| -rw-r--r-- | Documentation/gpu/amdgpu/amdgpu-glossary.rst | 15 | ||||
| -rw-r--r-- | Documentation/gpu/drm-internals.rst | 32 | ||||
| -rw-r--r-- | Documentation/gpu/drm-kms-helpers.rst | 43 | ||||
| -rw-r--r-- | Documentation/gpu/drm-usage-stats.rst | 21 | ||||
| -rw-r--r-- | Documentation/gpu/introduction.rst | 60 | ||||
| -rw-r--r-- | Documentation/gpu/todo.rst | 25 | ||||
| -rw-r--r-- | Documentation/gpu/vkms.rst | 6 |
7 files changed, 175 insertions, 27 deletions
diff --git a/Documentation/gpu/amdgpu/amdgpu-glossary.rst b/Documentation/gpu/amdgpu/amdgpu-glossary.rst index 859dcec6c6f9..326896e9800d 100644 --- a/Documentation/gpu/amdgpu/amdgpu-glossary.rst +++ b/Documentation/gpu/amdgpu/amdgpu-glossary.rst @@ -8,12 +8,19 @@ we have a dedicated glossary for Display Core at .. glossary:: + active_cu_number + The number of CUs that are active on the system. The number of active + CUs may be less than SE * SH * CU depending on the board configuration. + CP Command Processor CPLIB Content Protection Library + CU + Compute Unit + DFS Digital Frequency Synthesizer @@ -68,12 +75,18 @@ we have a dedicated glossary for Display Core at PSP Platform Security Processor - RCL + RLC RunList Controller SDMA System DMA + SE + Shader Engine + + SH + SHader array + SMU System Management Unit diff --git a/Documentation/gpu/drm-internals.rst b/Documentation/gpu/drm-internals.rst index 38afed24a75c..5fd20a306718 100644 --- a/Documentation/gpu/drm-internals.rst +++ b/Documentation/gpu/drm-internals.rst @@ -207,6 +207,38 @@ Utilities :internal: +Unit testing +============ + +KUnit +----- + +KUnit (Kernel unit testing framework) provides a common framework for unit tests +within the Linux kernel. + +This section covers the specifics for the DRM subsystem. For general information +about KUnit, please refer to Documentation/dev-tools/kunit/start.rst. + +How to run the tests? +~~~~~~~~~~~~~~~~~~~~~ + +In order to facilitate running the test suite, a configuration file is present +in ``drivers/gpu/drm/tests/.kunitconfig``. It can be used by ``kunit.py`` as +follows: + +.. code-block:: bash + + $ ./tools/testing/kunit/kunit.py run --kunitconfig=drivers/gpu/drm/tests \ + --kconfig_add CONFIG_VIRTIO_UML=y \ + --kconfig_add CONFIG_UML_PCI_OVER_VIRTIO=y + +.. note:: + The configuration included in ``.kunitconfig`` should be as generic as + possible. + ``CONFIG_VIRTIO_UML`` and ``CONFIG_UML_PCI_OVER_VIRTIO`` are not + included in it because they are only required for User Mode Linux. + + Legacy Support Code =================== diff --git a/Documentation/gpu/drm-kms-helpers.rst b/Documentation/gpu/drm-kms-helpers.rst index c3ce91eecbc1..2d473bc64c9f 100644 --- a/Documentation/gpu/drm-kms-helpers.rst +++ b/Documentation/gpu/drm-kms-helpers.rst @@ -226,40 +226,43 @@ Panel Self Refresh Helper Reference HDCP Helper Functions Reference =============================== -.. kernel-doc:: drivers/gpu/drm/drm_hdcp.c +.. kernel-doc:: drivers/gpu/drm/display/drm_hdcp_helper.c :export: Display Port Helper Functions Reference ======================================= -.. kernel-doc:: drivers/gpu/drm/dp/drm_dp.c +.. kernel-doc:: drivers/gpu/drm/display/drm_dp_helper.c :doc: dp helpers -.. kernel-doc:: include/drm/dp/drm_dp_helper.h +.. kernel-doc:: include/drm/display/drm_dp.h :internal: -.. kernel-doc:: drivers/gpu/drm/dp/drm_dp.c +.. kernel-doc:: include/drm/display/drm_dp_helper.h + :internal: + +.. kernel-doc:: drivers/gpu/drm/display/drm_dp_helper.c :export: Display Port CEC Helper Functions Reference =========================================== -.. kernel-doc:: drivers/gpu/drm/dp/drm_dp_cec.c +.. kernel-doc:: drivers/gpu/drm/display/drm_dp_cec.c :doc: dp cec helpers -.. kernel-doc:: drivers/gpu/drm/dp/drm_dp_cec.c +.. kernel-doc:: drivers/gpu/drm/display/drm_dp_cec.c :export: Display Port Dual Mode Adaptor Helper Functions Reference ========================================================= -.. kernel-doc:: drivers/gpu/drm/dp/drm_dp_dual_mode_helper.c +.. kernel-doc:: drivers/gpu/drm/display/drm_dp_dual_mode_helper.c :doc: dp dual mode helpers -.. kernel-doc:: include/drm/dp/drm_dp_dual_mode_helper.h +.. kernel-doc:: include/drm/display/drm_dp_dual_mode_helper.h :internal: -.. kernel-doc:: drivers/gpu/drm/dp/drm_dp_dual_mode_helper.c +.. kernel-doc:: drivers/gpu/drm/display/drm_dp_dual_mode_helper.c :export: Display Port MST Helpers @@ -268,19 +271,19 @@ Display Port MST Helpers Overview -------- -.. kernel-doc:: drivers/gpu/drm/dp/drm_dp_mst_topology.c +.. kernel-doc:: drivers/gpu/drm/display/drm_dp_mst_topology.c :doc: dp mst helper -.. kernel-doc:: drivers/gpu/drm/dp/drm_dp_mst_topology.c +.. kernel-doc:: drivers/gpu/drm/display/drm_dp_mst_topology.c :doc: Branch device and port refcounting Functions Reference ------------------- -.. kernel-doc:: include/drm/dp/drm_dp_mst_helper.h +.. kernel-doc:: include/drm/display/drm_dp_mst_helper.h :internal: -.. kernel-doc:: drivers/gpu/drm/dp/drm_dp_mst_topology.c +.. kernel-doc:: drivers/gpu/drm/display/drm_dp_mst_topology.c :export: Topology Lifetime Internals @@ -289,7 +292,7 @@ Topology Lifetime Internals These functions aren't exported to drivers, but are documented here to help make the MST topology helpers easier to understand -.. kernel-doc:: drivers/gpu/drm/dp/drm_dp_mst_topology.c +.. kernel-doc:: drivers/gpu/drm/display/drm_dp_mst_topology.c :functions: drm_dp_mst_topology_try_get_mstb drm_dp_mst_topology_get_mstb drm_dp_mst_topology_put_mstb drm_dp_mst_topology_try_get_port drm_dp_mst_topology_get_port @@ -323,13 +326,13 @@ MIPI DSI Helper Functions Reference Display Stream Compression Helper Functions Reference ===================================================== -.. kernel-doc:: drivers/gpu/drm/drm_dsc.c +.. kernel-doc:: drivers/gpu/drm/display/drm_dsc_helper.c :doc: dsc helpers -.. kernel-doc:: include/drm/drm_dsc.h +.. kernel-doc:: include/drm/display/drm_dsc.h :internal: -.. kernel-doc:: drivers/gpu/drm/drm_dsc.c +.. kernel-doc:: drivers/gpu/drm/display/drm_dsc_helper.c :export: Output Probing Helper Functions Reference @@ -353,13 +356,13 @@ EDID Helper Functions Reference SCDC Helper Functions Reference =============================== -.. kernel-doc:: drivers/gpu/drm/drm_scdc_helper.c +.. kernel-doc:: drivers/gpu/drm/display/drm_scdc_helper.c :doc: scdc helpers -.. kernel-doc:: include/drm/drm_scdc_helper.h +.. kernel-doc:: include/drm/display/drm_scdc_helper.h :internal: -.. kernel-doc:: drivers/gpu/drm/drm_scdc_helper.c +.. kernel-doc:: drivers/gpu/drm/display/drm_scdc_helper.c :export: HDMI Infoframes Helper Reference diff --git a/Documentation/gpu/drm-usage-stats.rst b/Documentation/gpu/drm-usage-stats.rst index 6c9f166a8d6f..92c5117368d7 100644 --- a/Documentation/gpu/drm-usage-stats.rst +++ b/Documentation/gpu/drm-usage-stats.rst @@ -105,6 +105,27 @@ object belong to this client, in the respective memory region. Default unit shall be bytes with optional unit specifiers of 'KiB' or 'MiB' indicating kibi- or mebi-bytes. +- drm-cycles-<str> <uint> + +Engine identifier string must be the same as the one specified in the +drm-engine-<str> tag and shall contain the number of busy cycles for the given +engine. + +Values are not required to be constantly monotonic if it makes the driver +implementation easier, but are required to catch up with the previously reported +larger value within a reasonable period. Upon observing a value lower than what +was previously read, userspace is expected to stay with that larger previous +value until a monotonic update is seen. + +- drm-maxfreq-<str> <uint> [Hz|MHz|KHz] + +Engine identifier string must be the same as the one specified in the +drm-engine-<str> tag and shall contain the maximum frequency for the given +engine. Taken together with drm-cycles-<str>, this can be used to calculate +percentage utilization of the engine, whereas drm-engine-<str> only reflects +time active without considering what frequency the engine is operating as a +percentage of it's maximum frequency. + =============================== Driver specific implementations =============================== diff --git a/Documentation/gpu/introduction.rst b/Documentation/gpu/introduction.rst index 25a56e9c0cfd..f05eccd2c07c 100644 --- a/Documentation/gpu/introduction.rst +++ b/Documentation/gpu/introduction.rst @@ -112,3 +112,63 @@ Please conduct yourself in a respectful and civilised manner when interacting with community members on mailing lists, IRC, or bug trackers. The community represents the project as a whole, and abusive or bullying behaviour is not tolerated by the project. + +Simple DRM drivers to use as examples +===================================== + +The DRM subsystem contains a lot of helper functions to ease writing drivers for +simple graphic devices. For example, the `drivers/gpu/drm/tiny/` directory has a +set of drivers that are simple enough to be implemented in a single source file. + +These drivers make use of the `struct drm_simple_display_pipe_funcs`, that hides +any complexity of the DRM subsystem and just requires drivers to implement a few +functions needed to operate the device. This could be used for devices that just +need a display pipeline with one full-screen scanout buffer feeding one output. + +The tiny DRM drivers are good examples to understand how DRM drivers should look +like. Since are just a few hundreds lines of code, they are quite easy to read. + +External References +=================== + +Delving into a Linux kernel subsystem for the first time can be an overwhelming +experience, one needs to get familiar with all the concepts and learn about the +subsystem's internals, among other details. + +To shallow the learning curve, this section contains a list of presentations +and documents that can be used to learn about DRM/KMS and graphics in general. + +There are different reasons why someone might want to get into DRM: porting an +existing fbdev driver, write a DRM driver for a new hardware, fixing bugs that +could face when working on the graphics user-space stack, etc. For this reason, +the learning material covers many aspects of the Linux graphics stack. From an +overview of the kernel and user-space stacks to very specific topics. + +The list is sorted in reverse chronological order, to keep the most up-to-date +material at the top. But all of them contain useful information, and it can be +valuable to go through older material to understand the rationale and context +in which the changes to the DRM subsystem were made. + +Conference talks +---------------- + +* `An Overview of the Linux and Userspace Graphics Stack <https://www.youtube.com/watch?v=wjAJmqwg47k>`_ - Paul Kocialkowski (2020) +* `Getting pixels on screen on Linux: introduction to Kernel Mode Setting <https://www.youtube.com/watch?v=haes4_Xnc5Q>`_ - Simon Ser (2020) +* `Everything Great about Upstream Graphics <https://www.youtube.com/watch?v=kVzHOgt6WGE>`_ - Daniel Vetter (2019) +* `An introduction to the Linux DRM subsystem <https://www.youtube.com/watch?v=LbDOCJcDRoo>`_ - Maxime Ripard (2017) +* `Embrace the Atomic (Display) Age <https://www.youtube.com/watch?v=LjiB_JeDn2M>`_ - Daniel Vetter (2016) +* `Anatomy of an Atomic KMS Driver <https://www.youtube.com/watch?v=lihqR9sENpc>`_ - Laurent Pinchart (2015) +* `Atomic Modesetting for Drivers <https://www.youtube.com/watch?v=kl9suFgbTc8>`_ - Daniel Vetter (2015) +* `Anatomy of an Embedded KMS Driver <https://www.youtube.com/watch?v=Ja8fM7rTae4>`_ - Laurent Pinchart (2013) + +Slides and articles +------------------- + +* `Understanding the Linux Graphics Stack <https://bootlin.com/doc/training/graphics/graphics-slides.pdf>`_ - Bootlin (2022) +* `DRM KMS overview <https://wiki.st.com/stm32mpu/wiki/DRM_KMS_overview>`_ - STMicroelectronics (2021) +* `Linux graphic stack <https://studiopixl.com/2017-05-13/linux-graphic-stack-an-overview>`_ - Nathan Gauër (2017) +* `Atomic mode setting design overview, part 1 <https://lwn.net/Articles/653071/>`_ - Daniel Vetter (2015) +* `Atomic mode setting design overview, part 2 <https://lwn.net/Articles/653466/>`_ - Daniel Vetter (2015) +* `The DRM/KMS subsystem from a newbie’s point of view <https://bootlin.com/pub/conferences/2014/elce/brezillon-drm-kms/brezillon-drm-kms.pdf>`_ - Boris Brezillon (2014) +* `A brief introduction to the Linux graphics stack <https://blogs.igalia.com/itoral/2014/07/29/a-brief-introduction-to-the-linux-graphics-stack/>`_ - Iago Toral (2014) +* `The Linux Graphics Stack <https://blog.mecheye.net/2012/06/the-linux-graphics-stack/>`_ - Jasper St. Pierre (2012) diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst index 127e76ee0b2d..513b20ccef1e 100644 --- a/Documentation/gpu/todo.rst +++ b/Documentation/gpu/todo.rst @@ -603,6 +603,31 @@ Level: Advanced Better Testing ============== +Add unit tests using the Kernel Unit Testing (KUnit) framework +-------------------------------------------------------------- + +The `KUnit <https://www.kernel.org/doc/html/latest/dev-tools/kunit/index.html>`_ +provides a common framework for unit tests within the Linux kernel. Having a +test suite would allow to identify regressions earlier. + +A good candidate for the first unit tests are the format-conversion helpers in +``drm_format_helper.c``. + +Contact: Javier Martinez Canillas <javierm@redhat.com> + +Level: Intermediate + +Convert Kernel Selftests (kselftest) to KUnit tests when appropriate +-------------------------------------------------------------------- + +Many of the `Kselftest <https://www.kernel.org/doc/html/latest/dev-tools/kselftest.html>`_ +tests in DRM could be converted to Kunit tests instead, since that framework +is more suitable for unit testing. + +Contact: Javier Martinez Canillas <javierm@redhat.com> + +Level: Starter + Enable trinity for DRM ---------------------- diff --git a/Documentation/gpu/vkms.rst b/Documentation/gpu/vkms.rst index 9c873c3912cc..973e2d43108b 100644 --- a/Documentation/gpu/vkms.rst +++ b/Documentation/gpu/vkms.rst @@ -102,12 +102,6 @@ Debugging: - kms_plane: some test cases are failing due to timeout on capturing CRC; -- kms_flip: when running test cases in sequence, some successful individual - test cases are failing randomly; when individually, some successful test - cases display in the log the following error:: - - [drm:vkms_prepare_fb [vkms]] ERROR vmap failed: -4 - Virtual hardware (vblank-less) mode: - VKMS already has support for vblanks simulated via hrtimers, which can be |