On Jul 8, 2012, at 2:11 AM, Andriy Gapon wrote: > acpi_cpu.c has a block of code to write CST_CNT to SMI_CMD, but the block is > under #ifdef notyet. It seems that the code was added that many years ago and > never enabled. > Now, judging from the reports I've seen on this mailing list, it appears that > _CST changes do happen and the driver seem to handle them sufficiently well. > I think that a lot of modern platforms do not even provide CST_CNT and assume > that an OS is able to handle C-state change notifications. > So, I guess that it should be safe to enable the code in question now. > > Could anyone with a FreeBSD laptop and non-zero CST_CNT in FADT please test > this?
It was only under an #ifdef because at the time our CST implementation couldn't handle CST changes cleanly. I had added some support for it, but since it couldn't be tested, I wasn't sure how actual hardware would behave. I think it's fine to enable now. I think 2007-era Thinkpads were some of the first to add this feature. -Nate _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-acpi To unsubscribe, send any mail to "[email protected]"
