Re: ACPI and VIA C3

[Ludwig Meyerhoff <ludwig@antar.de>]

Hallo!

Actually, other ACPI modules work quite fine, like the "thermal_zone"
(says the system has about 27°C) or the "button" ...

I now tried a 2.6.6 kernel with the "epia1" patch,
a 2.6.7 with the acpi (acpi.sourceforge.net) patch
and a 2.4.20 standard kernel ...
The processor is recognized to have C2 capability by the 2.4.20 kernel
only, and running that kernel the powermeter goes down by 10W (of 30) ...


Here is the beginning of dmesg ...   There is only one complaint
regarding "No local APIC present or hardware disabled", but that is also
on the 2.4.20 kernel ...




BIOS-provided physical RAM map:
 BIOS-e820: 0000000000000000 - 000000000009fc00 (usable)
 BIOS-e820: 000000000009fc00 - 00000000000a0000 (reserved)
 BIOS-e820: 00000000000f0000 - 0000000000100000 (reserved)
 BIOS-e820: 0000000000100000 - 000000001dff0000 (usable)
 BIOS-e820: 000000001dff0000 - 000000001dff3000 (ACPI NVS)
 BIOS-e820: 000000001dff3000 - 000000001e000000 (ACPI data)
 BIOS-e820: 00000000ffff0000 - 0000000100000000 (reserved)
479MB LOWMEM available.
On node 0 totalpages: 122864
  DMA zone: 4096 pages, LIFO batch:1
  Normal zone: 118768 pages, LIFO batch:16
  HighMem zone: 0 pages, LIFO batch:1
DMI 2.2 present.
ACPI: RSDP (v000 AWARD                                     ) @ 0x000f7800
ACPI: RSDT (v001 AWARD  AWRDACPI 0x42302e31 AWRD 0x00000000) @ 0x1dff3000
ACPI: FADT (v001 AWARD  AWRDACPI 0x42302e31 AWRD 0x00000000) @ 0x1dff3040
ACPI: DSDT (v001 AWARD  AWRDACPI 0x00001000 MSFT 0x0100000d) @ 0x00000000
ACPI: PM-Timer IO Port: 0x5008
Built 1 zonelists
Kernel command line: root=/dev/hda5 ro acpi=force apic=force
No local APIC present or hardware disabled
Initializing CPU#0
PID hash table entries: 2048 (order 11: 16384 bytes)
Detected 735.089 MHz processor.
Using pmtmr for high-res timesource
Console: colour VGA+ 80x25
Memory: 479660k/491456k available (1317k kernel code, 11052k reserved,
717k data, 204k init, 0k highmem)
Checking if this processor honours the WP bit even in supervisor mode... Ok.
Calibrating delay loop... 1458.17 BogoMIPS
Security Scaffold v1.0.0 initialized
Dentry cache hash table entries: 65536 (order: 6, 262144 bytes)
Inode-cache hash table entries: 32768 (order: 5, 131072 bytes)
Mount-cache hash table entries: 512 (order: 0, 4096 bytes)
CPU:     After generic identify, caps: 00803035 80803035 00000000 00000000
CPU: L1 I Cache: 64K (32 bytes/line), D cache 64K (32 bytes/line)
CPU: L2 Cache: 64K (32 bytes/line)
CPU:     After all inits, caps: 00803135 80803035 00000000 00000000
CPU: Centaur VIA Ezra stepping 08
Checking 'hlt' instruction... OK.
Checking for popad bug... OK.




Saluti!

Ludwig


David Goodenough wrote:
> On Saturday 26 June 2004 18:37, Ludwig Meyerhoff wrote:
>
> > Hallo!
> >
> > I have a VIA C3 (Ezra) processor. It is very nice for "normal"
> > applications, as it takes only a few watt.
> >
> > I have a problem with the ACPI support of the kernel ...
> > While 2.4.20 recognizes the processor to support C1 and C2 states, the
> > 2.4.26 does not, as the 2.6.6 does not also.
> >
> > AFAIK the ACPI support has been rewritten for the 2.6 kernel and
> > backported to 2.4 in 2.4.23 or something ...
> >
> > Now: does anyone know how I can achieve full ACPI support for my
> > processor in a more recent kernel than 2.4.20? In special I would like
> > to use frequency scaling/throttling, as most of the time my small
> > computer does nothing.
> >
> >
> >
> > Saluti!
> >
> > Ludwig
>
>
> You might want to check wether the newer code regards the ACPI
> BIOS as being too old.  I have various machine which disable ACPI
> support because of old BIOS, but on all of them acpi=force as a 
> kernel option turns it back on with no obvious bad side effects.
>
> However this should be obvious by reading /var/log/dmesg, 
> quite early on there should be a message saying that this is
> necessary.
>
> David