1.. _display_todos: 2 3============================== 4AMDGPU - Display Contributions 5============================== 6 7First of all, if you are here, you probably want to give some technical 8contribution to the display code, and for that, we say thank you :) 9 10This page summarizes some of the issues you can help with; keep in mind that 11this is a static page, and it is always a good idea to try to reach developers 12in the amdgfx or some of the maintainers. Finally, this page follows the DRM 13way of creating a TODO list; for more information, check 14'Documentation/gpu/todo.rst'. 15 16Gitlab issues 17============= 18 19Users can report issues associated with AMD GPUs at: 20 21- https://gitlab.freedesktop.org/drm/amd 22 23Usually, we try to add a proper label to all new tickets to make it easy to 24filter issues. If you can reproduce any problem, you could help by adding more 25information or fixing the issue. 26 27Level: diverse 28 29IGT 30=== 31 32`IGT`_ provides many integration tests that can be run on your GPU. We always 33want to pass a large set of tests to increase the test coverage in our CI. If 34you wish to contribute to the display code but are unsure where a good place 35is, we recommend you run all IGT tests and try to fix any failure you see in 36your hardware. Keep in mind that this failure can be an IGT problem or a kernel 37issue; it is necessary to analyze case-by-case. 38 39Level: diverse 40 41.. _IGT: https://gitlab.freedesktop.org/drm/igt-gpu-tools 42 43Compilation 44=========== 45 46Fix compilation warnings 47------------------------ 48 49Enable the W1 or W2 warning level in the kernel compilation and try to fix the 50issues on the display side. 51 52Level: Starter 53 54Fix compilation issues when using um architecture 55------------------------------------------------- 56 57Linux has a User-mode Linux (UML) feature, and the kernel can be compiled to 58the **um** architecture. Compiling for **um** can bring multiple advantages 59from the test perspective. We currently have some compilation issues in this 60area that we need to fix. 61 62Level: Intermediate 63 64Code Refactor 65============= 66 67Add prefix to DC functions to improve the debug with ftrace 68----------------------------------------------------------- 69 70The Ftrace debug feature (check 'Documentation/trace/ftrace.rst') is a 71fantastic way to check the code path when developers try to make sense of a 72bug. Ftrace provides a filter mechanism that can be useful when the developer 73has some hunch of which part of the code can cause the issue; for this reason, 74if a set of functions has a proper prefix, it becomes easy to create a good 75filter. Additionally, prefixes can improve stack trace readability. 76 77The DC code does not follow some prefix rules, which makes the Ftrace filter 78more complicated and reduces the readability of the stack trace. If you want 79something simple to start contributing to the display, you can make patches for 80adding prefixes to DC functions. To create those prefixes, use part of the file 81name as a prefix for all functions in the target file. Check the 82'amdgpu_dm_crtc.c` and `amdgpu_dm_plane.c` for some references. However, we 83strongly advise not to send huge patches changing these prefixes; otherwise, it 84will be hard to review and test, which can generate second thoughts from 85maintainers. Try small steps; in case of double, you can ask before you put in 86effort. We recommend first looking at folders like dceXYZ, dcnXYZ, basics, 87bios, core, clk_mgr, hwss, resource, and irq. 88 89Level: Starter 90 91Reduce code duplication 92----------------------- 93 94AMD has an extensive portfolio with various dGPUs and APUs that amdgpu 95supports. To maintain the new hardware release cadence, DCE/DCN was designed in 96a modular design, making the bring-up for new hardware fast. Over the years, 97amdgpu accumulated some technical debt in the code duplication area. For this 98task, it would be a good idea to find a tool that can discover code duplication 99(including patterns) and use it as guidance to reduce duplications. 100 101Level: Intermediate 102 103Make atomic_commit_[check|tail] more readable 104--------------------------------------------- 105 106The functions responsible for atomic commit and tail are intricate and 107extensive. In particular `amdgpu_dm_atomic_commit_tail` is a long function and 108could benefit from being split into smaller helpers. Improvements in this area 109are more than welcome, but keep in mind that changes in this area will affect 110all ASICs, meaning that refactoring requires a comprehensive verification; in 111other words, this effort can take some time for validation. 112 113Level: Advanced 114 115Documentation 116============= 117 118Expand kernel-doc 119----------------- 120 121Many DC functions do not have a proper kernel-doc; understanding a function and 122adding documentation is a great way to learn more about the amdgpu driver and 123also leave an outstanding contribution to the entire community. 124 125Level: Starter 126 127Beyond AMDGPU 128============= 129 130AMDGPU provides features that are not yet enabled in the userspace. This 131section highlights some of the coolest display features, which could be enabled 132with the userspace developer helper. 133 134Enable underlay 135--------------- 136 137AMD display has this feature called underlay (which you can read more about at 138'Documentation/GPU/amdgpu/display/mpo-overview.rst') which is intended to 139save power when playing a video. The basic idea is to put a video in the 140underlay plane at the bottom and the desktop in the plane above it with a hole 141in the video area. This feature is enabled in ChromeOS, and from our data 142measurement, it can save power. 143 144Level: Unknown 145 146Adaptive Backlight Modulation (ABM) 147----------------------------------- 148 149ABM is a feature that adjusts the display panel's backlight level and pixel 150values depending on the displayed image. This power-saving feature can be very 151useful when the system starts to run off battery; since this will impact the 152display output fidelity, it would be good if this option was something that 153users could turn on or off. 154 155Level: Unknown 156 157 158HDR & Color management & VRR 159---------------------------- 160 161HDR, Color Management, and VRR are huge topics and it's hard to put these into 162concise ToDos. If you are interested in this topic, we recommend checking some 163blog posts from the community developers to better understand some of the 164specific challenges and people working on the subject. If anyone wants to work 165on some particular part, we can try to help with some basic guidance. Finally, 166keep in mind that we already have some kernel-doc in place for those areas. 167 168Level: Unknown 169