From 21dd98b0ef89f5a31927ce43ec4ed40ceef305da Mon Sep 17 00:00:00 2001 From: Rodrigo Siqueira Date: Mon, 22 Jan 2024 14:25:00 -0700 Subject: [PATCH] Documentation/gpu: Add an explanation about the DC weekly patches MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This commit introduces some explanation about the display team validation. Changes since V1: - Remove unprecise information about the DC process for now, can be added later on. - Jani: Fix bullets Cc: Mario Limonciello Cc: Alex Deucher Cc: Harry Wentland Cc: Hamza Mahfooz Cc: Christian König Cc: Aurabindo Pillai Reviewed-by: Mario Limonciello Acked-by: Christian König Acked-by: Hamza Mahfooz Signed-off-by: Rodrigo Siqueira Signed-off-by: Alex Deucher --- Documentation/gpu/amdgpu/display/index.rst | 76 ++++++++++++++++++++-- 1 file changed, 69 insertions(+), 7 deletions(-) diff --git a/Documentation/gpu/amdgpu/display/index.rst b/Documentation/gpu/amdgpu/display/index.rst index b09d1434754d..aa89e8f9ab89 100644 --- a/Documentation/gpu/amdgpu/display/index.rst +++ b/Documentation/gpu/amdgpu/display/index.rst @@ -7,18 +7,80 @@ drm/amd/display - Display Core (DC) AMD display engine is partially shared with other operating systems; for this reason, our Display Core Driver is divided into two pieces: -1. **Display Core (DC)** contains the OS-agnostic components. Things like +#. **Display Core (DC)** contains the OS-agnostic components. Things like hardware programming and resource management are handled here. -2. **Display Manager (DM)** contains the OS-dependent components. Hooks to the - amdgpu base driver and DRM are implemented here. +#. **Display Manager (DM)** contains the OS-dependent components. Hooks to the + amdgpu base driver and DRM are implemented here. For example, you can check + display/amdgpu_dm/ folder. + +------------------ +DC Code validation +------------------ + +Maintaining the same code base across multiple OSes requires a lot of +synchronization effort between repositories and exhaustive validation. In the +DC case, we maintain a tree to centralize code from different parts. The shared +repository has integration tests with our Internal Linux CI farm, and we run a +comprehensive set of IGT tests in various AMD GPUs/APUs (mostly recent dGPUs +and APUs). Our CI also checks ARM64/32, PPC64/32, and x86_64/32 compilation +with DCN enabled and disabled. + +When we upstream a new feature or some patches, we pack them in a patchset with +the prefix **DC Patches for **, which is created based on the latest +`amd-staging-drm-next `_. All of +those patches are under a DC version tested as follows: + +* Ensure that every patch compiles and the entire series pass our set of IGT + test in different hardware. +* Prepare a branch with those patches for our validation team. If there is an + error, a developer will debug as fast as possible; usually, a simple bisect + in the series is enough to point to a bad change, and two possible actions + emerge: fix the issue or drop the patch. If it is not an easy fix, the bad + patch is dropped. +* Finally, developers wait a few days for community feedback before we merge + the series. + +It is good to stress that the test phase is something that we take extremely +seriously, and we never merge anything that fails our validation. Follows an +overview of our test set: + +#. Manual test + * Multiple Hotplugs with DP and HDMI. + * Stress test with multiple display configuration changes via the user interface. + * Validate VRR behaviour. + * Check PSR. + * Validate MPO when playing video. + * Test more than two displays connected at the same time. + * Check suspend/resume. + * Validate FPO. + * Check MST. +#. Automated test + * IGT tests in a farm with GPUs and APUs that support DCN and DCE. + * Compilation validation with the latest GCC and Clang from LTS distro. + * Cross-compilation for PowerPC 64/32, ARM 64/32, and x86 32. + +In terms of test setup for CI and manual tests, we usually use: + +#. The latest Ubuntu LTS. +#. In terms of userspace, we only use fully updated open-source components + provided by the distribution official package manager. +#. Regarding IGT, we use the latest code from the upstream. +#. Most of the manual tests are conducted in the GNome but we also use KDE. + +Notice that someone from our test team will always reply to the cover letter +with the test report. + +-------------- +DC Information +-------------- The display pipe is responsible for "scanning out" a rendered frame from the GPU memory (also called VRAM, FrameBuffer, etc.) to a display. In other words, it would: -1. Read frame information from memory; -2. Perform required transformation; -3. Send pixel data to sink devices. +#. Read frame information from memory; +#. Perform required transformation; +#. Send pixel data to sink devices. If you want to learn more about our driver details, take a look at the below table of content: @@ -26,8 +88,8 @@ table of content: .. toctree:: display-manager.rst - dc-debug.rst dcn-overview.rst dcn-blocks.rst mpo-overview.rst + dc-debug.rst dc-glossary.rst