In addition to the AMDGPU feature pull request to DRM-Next last week that landed DRM format modifiers for old AMD GPUs and a variety of other improvements, a secondary set of AMDGPU feature work followed that last week in preparation for the upcoming Linux 7.3 merge window.

Alex Deucher on Friday sent out some additional feature updates for the AMDGPU driver of work to squeeze in for Linux 7.3 ahead of the effective cut-off of new feature material into DRM-Next ahead of the Linux 7.3 merge window opening in about two weeks.

Most notable with this follow-on pull request is more work by Valve's Timur Kristóf. Notably it contains a reset patch series for using the GFX IP block soft reset support for GFX7 era hardware, like Kaveri APUs, Hawaii dGPUs, Bonaire dGPUs, and others. Timur explained in that July patch series:

"GFX IP block soft reset has been implemented as recovery method so that we can have a way to reset just the GFX block without resetting the whole GPU or losing the contents of VRAM.

Fix up various things in the GFX7 code to prepare it to work with IP block soft reset. The main challenge was fixing up the MQD/HQD handling to ensure that it doesn't hang after the soft reset. There are also other minor fixups.

Rework the pre-existing GFX7 soft reset implementation like the reworked version on GFX8 to make it more robust. In practice, this means that it will now reset everything in the GFX IP block (instead of taking a guess at which parts need to be reset) to make it consistent, and it now also handles clock and power gating to make sure not to degrade GPU functionality after a GFX IP block soft reset.

This improves current user experience on all GFX7 chips:

On Kaveri and Kabini there is currently no working GPU recovery method so those chips currently require the user to manually reset the computer when there was a hang.

On Hawaii and Bonaire, the current GPU recovery method always clears the contents of VRAM, which means that a buggy (hanging) app can crash the whole graphical session, which is less than ideal.

Using GFX IP block soft reset means that we can now have a working recovery on GFX7 APUs and we can also move on from GFX hangs on dGPUs without crashing the whole system."

By way of this end-of-week AMDGPU pull request, those improvements for aging AMD Radeon graphics should be part of the upcoming Linux 7.3 merge window. The list of those last minute feature patches for the AMD kernel graphics driver for Linux 7.3 can be found via this pull request.