Graphics Driver Changes Begin Lining Up For Linux 5.18

The first set of feature updates have been submitted to DRM-Next for staging until the Linux 5.18 kernel cycle begins around the end of March.

It was less than one week ago Linux 5.17-rc1 released that marked the end of the merge window for Linux 5.17. However, due to the cut-off of new DRM-Next material happening prior to the merge window, there is already a lot of new code ready to get staged in DRM-Next for the follow-on kernel cycle (5.18).

Sent out today were the first of several drm-misc-next pull requests expected for Linux 5.18. The drm-misc-next area continues collecting the Direct Rendering Manager changes for the core subsystem code and smaller drivers. Expect more drm-misc-next pull requests along with the big Intel and AMD driver feature pull requests to continue coming over the next several weeks.

The Arm SoCs with mainline display drivers send in their updates by way of DRM-Misc as do the other smaller DRM drivers.

With today's drm-misc-next pull to kick off Linux 5.18 graphics/display driver work, some of the initial highlights include:

- Intel's buddy allocator code has been promoted out of the i915 driver and into the core/common DRM area so it can be re-used by other drivers. The AMDGPU driver in particular has been interested in using this buddy allocator.

- Microsoft head-mounted displays (HMDs) are now better handled. The DRM EDID code adds support for parsing the "specialized monitor" EDID extension used by Microsoft HMDs. In turn this recognition is now also used for setting the "non-desktop" DRM property for indicating to compositors that this is a VR headset / HMD and not to extend it as another desktop monitor.

- Improved DRM's EDID parser for deep color handling.

- The open-source NVIDIA "Nouveau" driver now supports higher bit-rates for DisplayPort / eDP connections.

- The ASpeed AST2600 code has added wide-screen support so 16:9 and 16:10 resolutions are supported.

- The Virtual KMS "VKMS" driver now supports multiple overlay planes.

- A new driver has been added for ChromeOS privacy screen support. This is a new ACPI platform driver for ChromeOS privacy screen support for select devices already shipping with this built-in electronic privacy screen.

- The VC4 DRM driver code notably used by the Raspberry Pi 4 will now handover display from firmware to the VC4 driver code more gracefully.

- More of the smaller drivers converting to atomic mode-setting.

- Panfrost adds initial support for dual core group GPUs. The patch explains, "On a dual core group GPUs (such as T628) fragment shading can be performed over all cores (because a fragment shader job doesn't need coherency between threads), however vertex shading requires to be run on the same core group as the tiler (which always lives in core group 0). As a first step to support T628 power on only the first core group (so no jobs are scheduled on the second one). This makes T628 look like every other Midgard GPU (and throws away up to half the cores). With this patch panfrost is able to drive T628 (r1p0) GPU on some armv8 SoCs (in particular BE-M1000). Without the patch rendering is horriby broken (desktop is completely unusable) and eventually the GPU locks up (it takes from a few seconds to a couple of minutes)."

The list of patches ready so far for DRM-Next from the miscellaneous area can be found via this mailing list post.