Date: Mon, 9 Jul 2012 19:01:34 +0000 From: "Moore, Robert" <robert.moore@intel.com> To: Ian Smith <smithi@nimnet.asn.au>, Nate Lawson <nate@root.org> Cc: "freebsd-acpi@freebsd.org" <freebsd-acpi@freebsd.org>, Andriy Gapon <avg@freebsd.org> Subject: RE: disabled CST_CNT write Message-ID: <94F2FBAB4432B54E8AACC7DFDE6C92E346B0A852@ORSMSX101.amr.corp.intel.com> In-Reply-To: <20120710014934.J42038@sola.nimnet.asn.au> References: <4FF94EC4.1060109@FreeBSD.org> <023CA42F-C5FD-4F67-AD70-84DE68B3FBA8@root.org> <20120710014934.J42038@sola.nimnet.asn.au>
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> This Thinkpad T23 with latest (Oct2006) BIOS & EC shows no FADT .. but > FACP has CST_CNT=3D0xf4. Is that relevant at all? An oddity of ACPI -- the FADT has the signature "FACP". > -----Original Message----- > From: owner-freebsd-acpi@freebsd.org [mailto:owner-freebsd- > acpi@freebsd.org] On Behalf Of Ian Smith > Sent: Monday, July 09, 2012 9:06 AM > To: Nate Lawson > Cc: freebsd-acpi@freebsd.org; Andriy Gapon > Subject: Re: disabled CST_CNT write >=20 > On Sun, 8 Jul 2012 09:49:57 -0700, Nate Lawson wrote: > > 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? >=20 > This Thinkpad T23 with latest (Oct2006) BIOS & EC shows no FADT .. but > FACP has CST_CNT=3D0xf4. Is that relevant at all? >=20 > > 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. >=20 > T43? Maybe it's time I upgraded :) >=20 > cheers, Ian > _______________________________________________ > freebsd-acpi@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-acpi > To unsubscribe, send any mail to "freebsd-acpi-unsubscribe@freebsd.org"
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