As I pointed out in some other mail, that drivers allow to execute (quite) old userspace X on recent versions. E.g. gen2/gen3 Intel GPUs are untested on drm2, I saw some users doing something with Thinkpads T60 still.

This is not an objection against removing the dev/drm completely, since I believe that e.g. pre-radeon ATI cards (Mach etc) or Sis or whatever else of PCI/AGP kind are already physically decayed.

The intel dri1 drm driver can go, it would need an older DDX to be of any use afaik. drm2/intelkms work well enough on Gen3, it's the newest Intel platform I have access to for testing Mesa and Xorg updates and I expect Gen2 would be the same. It is just Gen1 that still has UMS support in the current DDX and that is unaccelerated on current Xorg because it relies on XAA.

Removal of the radeon dri1 driver may be a bit premature at this time given we do not yet have radeonkms working on any tier2, although someone mentions getting close in a recent ML thread. I have been trying to get the old ati-ums driver working with current Xorg for the benefit of tier2s until radeonkms is working on more than just x86. Even if we can get radeonkms running on powerpc64, there is still a use for old radeon on powerpc(32) as it lacks 64bit atomics that are needed by radeonkms.

The rest of the dri1 drivers should stay to support the video hardware from other than the Big3. To make actual use of them requires userland drivers not present since Mesa 8. I intend to provide the older drivers from Mesa 7.11 in a port (mesa-drivers-legacy/dri1) that co-exists with current drivers and uses same libs. Some of the hardware that has dri1 drivers does not have 2D acceleration in Xorg > 1.12 due to the removal of XAA, so a legacy Xorg would be required to have both 2D and 3D acceleration. Unfortunately, my previous offer for a xorg-server-legacy was turned down due to concerns over dependency handling until such time we have provide/requires or some other mechanism to allow xorg-server-legacy provide xorg-server. Ultimately, I would like to update the dri1 drivers such that we can use a single current shared drm for the old dri1 drivers and the new kms drivers, but I jave more work to do in userland before I stick my nose in the kernel.

P.S. I have a collection of video cards with dri1 support and the hardware has not physically decayed. On the contrary, they have held up quite well while some of the more recent cards have cooked themselves (popped caps, bad solder joints, etc).