So if BIOS does not lock the SMI disabling so Xenomai kernel can disable SMI. Then if the x86 PC system can work this way, there will be no problem I think because the SMBus code is used for a better performance only I think.
The fans start rotating after pressing the power-on switch. I wonder if the fan speed control is compulsory for the correct function of a computer. ACPI spec does not talk about any necessity of the running of the SMBus code. I wonder if laptop computers work with Xenomai without SMI. Regards On Mon, Jun 18, 2012 at 6:38 PM, Lennart Sorensen <[email protected]> wrote: > On Sun, Jun 17, 2012 at 05:25:08PM +0430, ali hagigat wrote: >> I think SMI needs some initialization from BIOS and then Linux kernel. >> The Linux kernel has some CONFIG_ variables to disable/enable SMI. >> In theory a motherboard can be built to generate SMI without the >> software help. But I think OEMs do not build such a board. So I think >> an x86 PC hard real time system is possible for today's PCs. >> >> Please correct me if I am wrong. > > The majority of systems I have seen do have SMI enabled at all times > and no way to turn it off. > > IBM even released a kernel driver to allow linux users to disable SMI on > some xSeries servers, but they must also handle certain fan controllers > from linux in that case since the SMI BIOS code is no longer doing it. > For those doing real time, this is acceptable to have to do, certainly > much better than having the SMI BIOS code interrupting real time just > to check on the fans. > > I do not believe linux has any way to turn it off. It is rather system > specific. All I see is CONFIG_GOOGLE_SMI which is specific to google's > machines. Also CONFIG_IBM_RTL (IBM Premium Real Time Mode). > > -- > Len Sorensen _______________________________________________ Xenomai mailing list [email protected] http://www.xenomai.org/mailman/listinfo/xenomai
