Date: Thu, 28 Feb 2008 10:25:37 +0200 From: Andriy Gapon <avg@icyb.net.ua> To: freebsd-acpi@freebsd.org Subject: mismatch between FACP and chipset spec Message-ID: <47C67001.20101@icyb.net.ua>
next in thread | raw e-mail | index | archive | help
As some of you probably already know I have a motherboard based on 440BX/PIIX4E chipset: http://www.geocities.com/SiliconValley/3686/delta_mp2.html Here's some info from ACPI tables: PM1a_EVT_BLK=0x4000-0x4003 PM1a_CNT_BLK=0x4040-0x4041 PM_TMR_BLK=0x4008-0x400b I know that in my case 0x4000 is a base address of "Power Management IO Space" (as defined by PIIX4 specification). I see that descriptions of the registers and their bits match between ACPI specification and PIIX4 specification for registers in PM1a_EVT_BLK (PMSTS and PMEN registers in PIIX4 parlance) and PM_TMR_BLK (PMTMP register in PIIX4 parlance). But addresses given for PM1a_CNT_BLK are not documented at all! On the other hand ACPI description of that register perfectly matches description of PIIX4 PMCNTRL register that is located at 0x4004 with a given base address. So, this is 0x4040 vs. 0x4004, looks like a possible typo/mistake by an author of ACPI tables for this motherboard. Question: is there any way I can way override the address of PM1a_CNT_BLK? My guess is that there is zero chance that there would be any BIOS updates for this old and exotic motherboard (MP2-BX-X). I think that this register is mostly useful for BM_RLD bit which is used in C3 support. I don't use C3 (there is an errata for C3 with this chipset and there is no PM2_CNT register defined anyway), but I am curios anyway. And a mostly unrelated question. From the following code it seems that linux won't go even into C2 state if there is any bus master activity detected (but I am not what would happen with "demotion"/"promotion"): http://lxr.linux.no/linux/drivers/acpi/processor_idle.c#L389 -- Andriy Gapon
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?47C67001.20101>