I would agree with Taylor, it is not tested well enough to be enabled by default and mainly unmaintained by now. I guess the better solution would be to attempt to integrate openchrome-drm instead at some point in the future. I think making viadrmums as kernel module is quite a good trade off right now for those who need/want to use it and it saves from kernel compilation. Will do pull-up to netbsd-10 soon for this change.
I may try to do some additional testing to verify how much it is utilized right now and were performance makes a difference (and likely would need to investigate what is wrong with VX900). I believe 3D acceleration is unsupported. On Sun, Aug 13, 2023 at 8:05 PM Taylor R Campbell <campbell+netbsd-source-change...@mumble.net> wrote: > > > Date: Thu, 10 Aug 2023 07:42:53 +1000 > > from: matthew green <m...@eterna.com.au> > > > > > Log Message: > > > viadrmums(4): build legacy VIA DRM UMS driver module for amd64. > > > > > > This driver is not built-in by default, thus loadable module can help > > > (un)lucky > > > > if it works, why isn't it in GENERIC as well as a module? > > Couple reasons: > > 1. I never adequately tested it. I started X a few years ago (and a > couple drm updates ago) but that's it. (Also only on 32-bit VIA.) > Maybe andvar can test it more extensively now, though -- glxgears, > x11perf, firefox, &c. > > Even better if we can get a sampling of code coverage, e.g. maybe > with dtrace to count function calls at least, to confirm it's > actually getting exercised. > > 2. It's a legacy UMS driver, which is inherently sketchy (display > configuration requires granting userland direct access to pci and > device registers) and increasingly unmaintained even upstream. > > So I put in some infrastructure to allow UMS drivers to be loaded > dynamically, so it wouldn't be necessary to have sketchy business > like that in the kernel by default. > > I kind of intended to give the same treatment to the other legacy > UMS drivers like mga (matrox), r128, sis, tdfx, &c., but it's been > a very low priority so I haven't gotten a round tuit (and I only > have hardware for mga and that's in a build server I don't like to > mess with).
