Ubuntu
linux-source-2.6.15 package

Missing C3 state - Centrino duo

Bug #55686 reported by frankuzzo
4
Affects Status Importance Assigned to Milestone
linux-source-2.6.15 (Ubuntu)
Invalid
Undecided
Unassigned

Bug Description

I don't have the C3 state. My laptop is an HP nc6320 with T2300E cpu. The same output comes on a sony vaio SZ2M/B (T2300)

cat /proc/acpi/processor/CPU0/power:

active state: C2
max_cstate: C8
bus master activity: 00000000
states:
    C1: type[C1] promotion[C2] demotion[--] latency[000] usage[00000010]
   *C2: type[C2] promotion[--] demotion[C1] latency[001] usage[01604681]

dmesg:
[17179569.184000] Initializing CPU#0
[17179573.468000] CPU: After generic identify, caps: bfe9fbff 00100000 00000000 00000000 0000c189 00000000 00000000
[17179573.468000] CPU: After vendor identify, caps: bfe9fbff 00100000 00000000 00000000 0000c189 00000000 00000000
[17179573.468000] CPU: L1 I cache: 32K, L1 D cache: 32K
[17179573.468000] CPU: L2 cache: 2048K
[17179573.468000] CPU: Hyper-Threading is disabled
[17179573.468000] CPU: After all inits, caps: bfe9fbff 00100000 00000000 00000040 0000c189 00000000 00000000
[..some for CPU#1..]
[17179576.080000] checking TSC synchronization across 2 CPUs: passed.
[17179576.084000] Brought up 2 CPUs
[17179579.076000] ACPI: CPU0 (power states: C1[C1] C2[C2])
[17179579.076000] ACPI: Processor [CPU0] (supports 8 throttling states)
[17179579.076000] ACPI: CPU1 (power states: C1[C1] C2[C2])
[17179579.076000] ACPI: Processor [CPU1] (supports 8 throttling states)

uname -a (latest updates already performed):

Linux franko-laptop 2.6.15-26-686 #1 SMP PREEMPT Thu Aug 3 03:13:28 UTC 2006 i686 GNU/Linux

I will promptly provide any info needed.

Thanks.

Revision history for this message
Bryan Quigley (bryanquigley) wrote :

Apologies if I got this wrong.

"I see only C0, C1, and C2. Why don't the other C-states show?

It's mostly a BIOS thing. Some BIOS hide C3/C4 when on AC power, and others show only C3 which is really a C4 underneath when on battery. Note that the 'max_cstate:C8' value in /proc/acpi/processor/*/power tells the maximum number of C-states the Linux kernel can handle, not the number of C-states implemented in your hardware."
-http://www.lesswatts.org/projects/powertop/faq.php

Changed in linux-source-2.6.15:
status: New → Invalid
To post a comment you must log in.
This report contains Public information  
Everyone can see this information.
Subscribing...

Other bug subscribers

Remote bug watches

Bug watches keep track of this bug in other bug trackers.