Date: Thu, 26 Mar 2009 09:37:50 -0400 From: John Baldwin <jhb@freebsd.org> To: freebsd-acpi@freebsd.org Cc: Daniel =?utf-8?q?Dvo=C5=99=C3=A1k?= <dandee@hellteam.net> Subject: Re: kern/108581: [sysctl] sysctl: hw.acpi.cpu.cx_lowest: Invalid argument Message-ID: <200903260937.51028.jhb@freebsd.org> In-Reply-To: <20090325223914.4387eeae@gluon.draftnet> References: <200903200030.n2K0U3iG011009@freefall.freebsd.org> <20090325223914.4387eeae@gluon.draftnet>
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On Wednesday 25 March 2009 6:39:14 pm Bruce Cran wrote: > On Fri, 20 Mar 2009 00:30:03 GMT > Daniel Dvo=C5=99=C3=A1k <dandee@hellteam.net> wrote: >=20 > > The following reply was made to PR kern/108581; it has been noted by > > GNATS. > >=20 > > From: =3D?UTF-8?Q?Daniel_Dvo=3DC5=3D99=3DC3=3DA1k?=3D <dandee@hellteam.= net> > > To: <bug-followup@FreeBSD.org>, > > <lars.stokholm@gmail.com> > > Cc: =20 > > Subject: Re: kern/108581: [sysctl] sysctl: hw.acpi.cpu.cx_lowest: > > Invalid argument Date: Fri, 20 Mar 2009 01:01:51 +0100 > >=20 > > This is a multi-part message in MIME format. > > =20 > > ------=3D_NextPart_000_0007_01C9A8F7.746C4190 > > Content-Type: text/plain; > > charset=3D"UTF-8" > > Content-Transfer-Encoding: quoted-printable > > =20 > > Hi acpi team, > > =3D20 > > today I have installed fbsd 7.1R on one box with this relativly old =3D > > error and I was surprised about results .. it is the same: > > =3D20 > > # uname -a > > FreeBSD X.Y.Z 7.1-RELEASE FreeBSD 7.1-RELEASE #0: Thu Jan 1 > > 14:37:25 =3D UTC 2009 > > root@logan.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC =3D i386 > > =20 > > # sysctl dev.cpu.0.cx_supported > > dev.cpu.0.cx_supported: C1/0 > > =20 > > # sysctl hw.acpi.cpu.cx_lowest=3D3DC1 > > hw.acpi.cpu.cx_lowest: C1 > > sysctl: hw.acpi.cpu.cx_lowest: Invalid argument > > =3D20 > > # sysctl hw.acpi.cpu.cx_lowest=3D3DC0 > > hw.acpi.cpu.cx_lowest: C1 > > sysctl: hw.acpi.cpu.cx_lowest: Invalid argument > > =3D20 > > # sysctl hw.acpi.cpu.cx_lowest=3D3DC1/0 > > hw.acpi.cpu.cx_lowest: C1 > > sysctl: hw.acpi.cpu.cx_lowest: Invalid argument > > =20 > > # dmesg -a | grep "acpi" > > acpi0: <ASUS P4S8X-X> on motherboard > > acpi0: Overriding SCI Interrupt from IRQ 9 to IRQ 20 > > acpi0: [ITHREAD] > > acpi0: Power Button (fixed) > > acpi0: reservation of 0, a0000 (3) failed > > acpi0: reservation of 100000, ff00000 (3) failed > > acpi_timer0: <24-bit timer at 3.579545MHz> port 0xe408-0xe40b on > > acpi0 acpi_button0: <Power Button> on acpi0 > > pcib0: <ACPI Host-PCI bridge> port 0xcf8-0xcff on acpi0 > > atkbdc0: <Keyboard controller (i8042)> port 0x60,0x64 irq 1 on acpi0 > > cpu0: <ACPI CPU> on acpi0 > > hw.acpi.cpu.cx_lowest: > > hw.acpi.cpu.cx_lowest >=20 > I think I've found the problem and have updated the PR kern/108581 > (http://www.freebsd.org/cgi/query-pr.cgi?pr=3Dkern/108581). The global > cpu_cx_count was being initialized to 0 in acpi_cpu_startup > (in /sys/dev/acpica/acpi_cpu.c) but code below it appears to assume that > it's been intialized to 3 because it only sets it if it's higher than > the current CPU supports - that is, cpu_cx_count should reflect the > highest Cx state that all CPUs support. >=20 > There's also a bug in the _CST section just below it; I think the line: >=20 > if (sc->cpu_cx_count > cpu_cx_count) >=20 > should be >=20 > if (sc->cpu_cx_count < cpu_cx_count) No, the code is doing things differently on purpose (though I'm not complet= ely=20 sure why). For _CST it sets cpu_cx_count to the maximum Cx level supported= =20 by any CPU in the system. For non-_CST it sets it to the maximum Cx level= =20 supported by all CPUs in the system. I think it is correct for cpu_cx_coun= t=20 to always start at 0 and only be bumped up to a higher setting. Setting it= =20 to 3 would be very wrong for the _CST case as I've seen CPUs that support C= 4. Note that C1 _always_ exists as it is simply the "hlt" instruction that has= =20 existed since the 8086. Only C2+ require power-saving extension support in= =20 the CPU, so cpu_cx_count should always end up >=3D 1. It would be interest= ing=20 if you could add some debug printfs to print out the values that=20 acpi_cpu_generic_cx_probe() computes for 'sc->cpu_cx_count' (sysctl dev.cpu= =20 could be useful for this) as well as all changes to the 'cpu_cx_count' glob= al=20 variable. =2D-=20 John Baldwin
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