Yes, but still, how much of IRIX's GPU stack did SGI contribute to Linux? How much of the current DRI/DRM/GPU Driver infrastructure is inspired from old UNIX de

Yes, but still, how much of IRIX's GPU stack did SGI contribute to Linux? How much of the current DRI/DRM/GPU Driver infrastructure is inspired from old UNIX designs? The point I am trying to make is that core kernel code is influenced by old, tried and trusted UNIX designs even if it wasn't up to the snuff in the scalability area for a long time. But the rest (incl. GPUs, USB stack, V4L2, driver support code (kobject) etc.) is a different story altogether - where old designs were either inaccessible or largely inapplicable due to different requirements and that's not an area of the Linux kernel anybody is proud of.