linux-drivers: add rga3 Rockchip multi-RGA driver

[felixjones]

Summary

Based on #2969

Ports rga3 driver from https://github.com/rockchip-linux/kernel to the latest kernel (hosted from a mirror https://github.com/felixjones/linux-rga3-mirror).

Developer guide for the rga3: https://github.com/sz-jack-01/linux-rga/blob/rkr3.5/docs/Rockchip_Developer_Guide_RGA_EN.md

This is another change from my gamescope experiments, rga3 has neat hardware rotation available, and AFBC 32x8 rotation with the RK3576 (where I'm getting gamescope working).

Testing

I had patched this driver for my gamescope experiments, it's been tested over the past few weeks.

Additional Context

Again, uses a mirror host here https://github.com/felixjones/linux-rga3-mirror for the rga3 driver

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AI Usage

NO

[sunshineinabox]

How are you managing rotating in gamescope using the pr recently submitted and wlroot?

[felixjones]

How are you managing rotating in gamescope using the pr recently submitted and wlroot?

The Raster Graphics Accelerator (RGA) hardware in the RK3576 provides hardware rotation (and scaling) of a CMA scanout buffer

I had issues with gamescope's Vulkan compositor and the rotation shader (stability and performance) so went down this route instead for rotating the image. Since then I've figured out the rotation shader issues - however using RGA for hardware rotation saves having to compile additional rotation shader permutations so I still see value in using RGA even with the VK compositor (hardware is there, might as well use it)

I'm currently cleaning up the patches for gamescope for the next PR, that will show the user code side of it

[aenertia]

I did something similar for rga1/2 and hacked in a wlroots level patch for operations which the RGA could handle, which natively got consumed by sway. Since it's unlikely this would get carried by upstream gamescope or wlroots ; perhaps extending wlroots with a patch to support all generations consistently makes more sense than carrying in gamescope itself. I haven't spent much time looking at gamescope on aarch64 so not sure that would actually make sense. But worth a thought.

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On Sun, 5 Jul 2026 at 12:20, Felix Jones ***@***.***> wrote: *felixjones* left a comment (ROCKNIX/distribution#2977) <#2977 (comment)> How are you managing rotating in gamescope using the pr recently submitted and wlroot? The Raster Graphics Accelerator (RGA) hardware in the RK3576 provides hardware rotation (and scaling) of a CMA scanout buffer I had issues with gamescope's Vulkan compositor and the rotation shader (stability and performance) so went down this route instead for rotating the image. Since then I've figured out the rotation shader issues - however using RGA for hardware rotation saves having to compile additional rotation shader permutations so I still see value in using RGA even with the VK compositor (hardware is there, might as well use it) I'm currently cleaning up the patches for gamescope for the next PR, that will show the user code side of it — Reply to this email directly, view it on GitHub <#2977?email_source=notifications&email_token=AACF5L2Y4CVU7YAHCKGHUPD5DGNLBA5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTIOBYGQZDIMZSHE42M4TFMFZW63VKON2WE43DOJUWEZLEUVSXMZLOOSWGM33PORSXEX3DNRUWG2Y#issuecomment-4884243299>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AACF5L2TFVT4DVP7J7PG2DD5DGNLBAVCNFSNUABFKJSXA33TNF2G64TZHM3TOMJRGIYDAMRRHNEXG43VMU5TIOBRGA4DONBYGMZ2C5QC> . Triage notifications, keep track of coding agent tasks and review pull requests on the go with GitHub Mobile for iOS <https://github.com/notifications/mobile/ios/AACF5L23MVVLJHVFEDMTNXD5DGNLBA5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTIOBYGQZDIMZSHE42M4TFMFZW63VKON2WE43DOJUWEZLEUVSXMZLOOSVGM33PORSXEX3JN5ZQ> and Android <https://github.com/notifications/mobile/android/AACF5L5VCXUOWXYCRLQERDT5DGNLBA5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTIOBYGQZDIMZSHE42M4TFMFZW63VKON2WE43DOJUWEZLEUVSXMZLOOSXGM33PORSXEX3BNZSHE33JMQ>. Download it today! You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[sunshineinabox]

ValveSoftware/gamescope#2228

yea I believe this PR is a better solution than the rotaiton shader on sm6115 noticed a similar issue but motivated me to get the hardware rotator working.

[felixjones]

Superseded by #3019