On Tuesday 19 October 2010, Arnd Bergmann wrote:
On Tuesday 19 October 2010 06:52:32 Dave Airlie wrote:
I might be able to find some hardware still lying around here that uses an i810. Not sure unless I go hunting it. But I get the impression that if the kernel is a single-CPU kernel there is not any problem anyway? Don't distros offer a non-smp kernel as an installation option in case the user needs it? So in reality how big a problem is this?
Not anymore, which is my old point of making a fuss. Nowadays in the modern distro world, we supply a single kernel that can at runtime decide if its running on SMP or UP and rewrite the text section appropriately with locks etc. Its like magic, and something like marking drivers as BROKEN_ON_SMP at compile time is really wrong when what you want now is a runtime warning if someone tries to hotplug a CPU with a known iffy driver loaded or if someone tries to load the driver when we are already in SMP mode.
We could make the driver run-time non-SMP by adding
if (num_present_cpus() > 1) { pr_err("i810 no longer supports SMP\n"); return -EINVAL; }
to the init function. That would cover the vast majority of the users of i810 hardware, I guess.
Some research showed that Intel never support i810/i815 SMP setups, but there was indeed one company (http://www.acorpusa.com at the time, now owned by a domain squatter) that made i815E based dual Pentium-III boards like this one: http://cgi.ebay.com/280319795096
The first person that can send me an authentic log file showing the use of X.org with DRM on a 2.6.35 kernel with two processors on that mainboard dated today or earlier gets a free upgrade to an AGP graphics card of comparable or better 3D performance from me. Please include the story how why you are running this machine with a new kernel.
i830 is harder, apparently some i865G boards support Pentium 4 with HT and even later dual-core processors.
Arnd