Valve has begun doing a lot to try to improve the open-source AMD Linux driver and the work of Andres Rodriguez is shining yet more light on their efforts.
Last week he sent in his first non-trivial patches to Mesa, which was adding VK_EXT_queue_global_priority support to the RADV open-source Radeon Vulkan driver. Andres Rodriguez had been working at AMD Toronto from 2011 but in November 2016 left the company to join Valve Software.
Besides working on RADV patches, today he announced a tool for debugging AMD GPUs. This tool simply called "gputool" so far just supports reading and decoding registers, but he's looking at adding register write support, dumping textures from vRAM, and other features.
The tool is currently hosted on GitHub. While it's basic right now, hopefully it will become much more versatile as time progresses, especially given Valve's recent focus on improving the AMD Linux driver stack.
Hopefully as well we could see AMD begin to support this tool... Intel has been developing intel-gpu-tool as a very nice suite of tools for debugging and testing with their open-source graphics driver, but we haven't seen anything similar out of AMD for their open-source driver. The intel-gpu-tool suite includes tests for libdrm, core ioctls, power management, KMS, sysfs interface, debugfs interfaces, and more. "IGT" also provides various libraries around the driver's interfaces, a library for submitting dummy GPU workloads, and much more.