On Fri, Feb 17, 2012 at 10:23:59AM +1100, Rod Whitworth wrote: > On Thu, 16 Feb 2012 10:43:28 -0800, Mike Larkin wrote: > > >Intel drivers later than 2.10 are KMS only, which OpenBSD does not support. > >The version in tree, based from CVS logs, is 2.9.1 with various backports > >added from later versions, and some one-off work done to support the > >later Intel chips in UMS. > > > > Thanks for the explanation. > > I guess that, for at least some time, I'm going to be able to > experience the sort of environment that users of archs that don't > support virtual consoles live with. One difference being that I will > have to sudo reboot to get to a console or sudo halt -p when I want a > shutdown. > > I did some reading about UMS vs KMS and noted a Phoronix page showing > that for many of their benchmarks ran faster in UMS. Not that it will > help us if we can't get UMS drivers for many GPUs. Or maybe some *BSD > dev will write a UMS driver, but don't hold your breath 8-)
Looks like you've swapped UMS and KMS at least partially. UMS (userland mode settings) is what XFree86 has done historically and it's still the only supported mode of operation for most X drivers in OpenBSD. Newer X drivers for both intel and radeon chipsets on Linux have switched to KMS (Kernel mode settings) where all the magic goo needed to initialized the graphics mode is moved into the kernel and driven by the DRI2 protocol from userland. Owain, kettenis and jcs backported the KMS code for ironlake and sandybridge chipsets from recent intel driver into the 2.9.1 UMS only driver to get some support. In both cases, since Linux switches to graphics mode early during boot and never goes back to text mode, the code to save / restore the text mode is missing. So to support newer chipset we need to implement KMS (and the TTM memory manager for the radeon driver) in the OpenBSD kernel. There have been some efforts toward this, FreeBSD is paying a developper on that, I've started a port during s2k11, but there is nothing ready for testing on our side yet, don't hold your breath. > > One intriguing thing I spotted was a statement that KMS allowed running > X without root privs. There is some tension there I expect. That's partially true. A bit more work is needed, but it's right that KMS is the way to go security wise too. > > Finally, having "wasted" a bunch of money (by my standards) getting a > machine that avoided broadcom wi-fi and nvidia graphics and had a > supported 10/100/1000 NIC (alc), I'd love to know what I should look > for in graphics in future in laptop land. > Currently, even if not perfect intel chipsets are useable under OpenBSD (I switched to a Thinkpad X220 as my main hacking laptop 2 month ago, and except for crappy iwn performance, it rocks). For ATI chips, if you stay away from chips that require KMS (mostly the recent integrated ones), there are still a bunch of laptops with separate GPUs that should just work with the ati 6.14.3 driver once we figure out how to put it back in OpenBSD. -- Matthieu Herrb
