00:11 <tokyovigilante> hi, is there any reference for which revisions within the bifrost family are targeted? Does -v10 refer to the driver iteration or hardware? Have a G31-based device which I am interested in panfrost development for (particularly panvk) and just wondering what is realistic in terms of future direction and extension support

00:25 <CounterPillow> -v10 refers to the hardware, v10 being Valhall with CSF (not bifrost)

00:29 <tokyovigilante> Ok thanks

00:29 <CounterPillow> For the supported devices (OpenGL and OpenGL ES, not Vulkan) in Panfrost, see https://docs.mesa3d.org/drivers/panfrost.html

00:29 <CounterPillow> Whether Vulkan makes sense on pre-Valhall hardware like Bifrost is a debated topic, last I heard Collabora is looking into supporting Vulkan there

00:32 <CounterPillow> If your target applications support both OpenGL ES and Vulkan, then using OpenGL ES on bifrost era hardware will probably yield the same performance as a hypothetical Vulkan driver would, if I've understood the general conversation surrounding that topic correctly

00:35 <tokyovigilante> Thanks, I'm working on mainline support for the Allwinner H616/700 series which has the G31. 3D performance is good for most software that is currently running on the vendor kernels (with a closed-source Mali blob) but there is some interest in software using OpenGL 3.3 as a minimum, or Vulkan. We are seeing good compatibility but limited performance using llvm for software rendering with Vulkan, and it would be good to explore wh

00:35 <tokyovigilante> ether a specific piece of software would perform sufficiently well with Vulkan to make further development on it worthwhile

00:36 <CounterPillow> Desktop OpenGL 3.3 is unlikely to ever happen as 3.2 would require geometry shaders, which the hardware doesn't implement

00:36 <tokyovigilante> Currently panvk is crashing on startup, and I haven't had much time yet to debug, as I'm still waiting for the display controller driver to go through the review process, and the audio driver is next on the list

00:37 <tokyovigilante> understood, that's why I was interested in panvk, but I'm not a graphics dev and wondered whether that was plausible

00:40 <CounterPillow> fwiw if the OpenGL 3.3 piece of software you specifically have in mind is OBS Studio, then a driver version override through the appropriate environment variable will make it work. OBS asks for a higher version OpenGL than it actually needs.

00:41 <CounterPillow> (or it doesn't use the extensions Panfrost doesn't implement but are mandated as part of the 3.3 spec, I don't know which one of the two)

00:46 <tokyovigilante> Thanks, I'm trying PCSX2, not OBS studio. Have done some small experimentation with version overrides so far but not been successful. It may be that the CPU is also not powerful enough, but definitely not with SW rendering plus emulating the PS2 CPU

01:01 <CounterPillow> tokyovigilante: with mainline+panfrost, if pcsx2 doesn't user timer queries or geometry shaders, then it should just run with the following environment variables set: MESA_GL_VERSION_OVERRIDE=3.3 MESA_GLSL_VERSION_OVERRIDE=330

01:02 <tokyovigilante> Definitely no geometry shaders. Will give it a try, thanks!

01:03 <CounterPillow> See also https://mesamatrix.net/#OpenGL3.3 to see the things above GL3.1 that panfrost implements

01:04 <tokyovigilante> Great, cheers

01:05 <HdkR> PCSX2 uses geometry shaders

01:05 <CounterPillow> That's unfortunate

01:06 <CounterPillow> I don't think geometry shaders were ever the fast way to do anything, so I'm surprised they chose to use them

01:06 <HdkR> Correctness tends to win over fast with emulation

01:47 <tokyovigilante> HdkR: for OpenGL only or both? performance wasn’t atrocious with llvmpipe SW vulkan, but not really playable.

01:47 <HdkR> tokyovigilante: Looks like it is in their GL, Vulkan, and D3D renderers. Which would make sense to have it everywhere

01:48 <tokyovigilante> vexing, so realistically without HW support it’s unlikely to be successful no matter what driver is in use?

01:48 <HdkR> Unless they have a fallback path that runs without it. Which I didn't look closely enough to see if they do

01:49 <HdkR> PS2's GPU is wacky so I could see them using it unconditionally

01:50 <tokyovigilante> thanks, will do some digging. hopefully once the ARM64 support settles in there will be some renewed interest in the lower-power devices, I get the impression the PCSX2 devs weren’t keen on HW with closed-source drivers

02:31 <tokyovigilante> Does look like geometry shaders were dropped last year, so a bit more promising - https://github.com/PCSX2/pcsx2/commit/bb75c78c1a28b762a1f90318113957080eac3475

02:32 <HdkR> Oh that's fun