This bug has also been reported as https://bugs.launchpad.net/ubuntu/+source/linux-source-2.6.20/+bug/119940 previously. Most recent kernel where this bug did not occur: unknown, I believe 2.4.2x was still correct Distribution: ubuntu gutsy Hardware Environment: Via C3 processor Problem Description: The output of "cat /proc/cpuinfo" is wrong for the Via C3 processor. It is being underreported by 33% of the true value. processor : 0 vendor_id : CentaurHauls cpu family : 6 model : 6 model name : VIA Samuel stepping : 2 cpu MHz : 400.179 [...] My CPU has 600 MHz.
your CPU also has speed scaling technology called longhaul. It's scaled down to its lowest frequency.
Thank you, Dave for the quick reply. (In reply to comment #1) > your CPU also has speed scaling technology called longhaul. > It's scaled down to its lowest frequency. I am afraid this unfortunately is incorrect. CPU scaling actually is broken as well on this CPU. But that is a separate issue, of course. AFAIK, this CPU runs at 600 and 300 MHz, but never 400 MHz. I think I remember that when the scaling was still working that "cat/proc/cpuinfo" would claim the machine was running either at 400MHz under load and 200 MHz when idle, in both cases underreporting by 33%. At any rate, the reported frequency never changes - even under high load - nowadays.
Rolf, have you tried recent kernels? It's been quite a bit of updates on cpufreq since 2.6.20 anyway.
Thanks, Natalie. I will try to test out a more recent kernel as soon as possible. Not really sure when that will be though. Maybe some excerpt from dmesg after I upgraded to feisty is of help? I will continue on to ubuntu gutsy later today. # uname -a Linux Rie 2.6.20-16-386 #2 Sun Sep 23 19:47:10 UTC 2007 i686 GNU/Linux [ 240.876877] longhaul: VIA C3 'Samuel' [C5A] CPU detected. Longhaul v1 supported. [ 240.876946] ACPI Exception (utmutex-0263): AE_BAD_PARAMETER, Thread E33AEA70 could not acquire Mutex [2] [20060707] [ 240.877016] longhaul: No ACPI support. Unsupported northbridge. [ 241.273098] acpi_cpufreq: Unknown symbol acpi_processor_notify_smm [ 241.275066] acpi_cpufreq: Unknown symbol acpi_processor_unregister_performance [ 241.277387] acpi_cpufreq: Unknown symbol acpi_processor_preregister_performance [ 241.279238] acpi_cpufreq: Unknown symbol acpi_processor_register_performance
Still the same on 2.6.22-14-386. Maybe the information I just attached to https://bugs.launchpad.net/ubuntu/+source/linux-source-2.6.20/+bug/50431 could be interesting for this bug as well. Feel free to ask for any further information. I'll happily provide it.
Any updates on this one ?
(In reply to comment #6) > Any updates on this one ? Unfortunately, no. I have not gotten around to keep pace with recompiling a new kernel every time. I am also reluctant to boot the machine too often. I don't think this problem will just magically go away, though. Somebody will actively have to push a fix. Before that, we'd need to triage where this is coming from. I'm looking for help and advise on that.
[ 240.876946] ACPI Exception (utmutex-0263): AE_BAD_PARAMETER, Thread E33AEA70 could not acquire Mutex [2] [20060707] [ 240.877016] longhaul: No ACPI support. Unsupported northbridge. This problem is not in the kernel. The ACPI table of this system is not correct. w/o ACPI and an unknown northbridge there is not much to do. Can you please provide the output of lspci -nn ?
Thomas, thank you for your support. I hope you don't mind me adding you to the cc list. Here is the information you requested. $ lspci -nn 00:00.0 Host bridge [0600]: Silicon Integrated Systems [SiS] 620 Host [1039:0620] (rev 02) 00:00.1 IDE interface [0101]: Silicon Integrated Systems [SiS] 5513 [IDE] [1039:5513] (rev d0) 00:01.0 ISA bridge [0601]: Silicon Integrated Systems [SiS] SiS85C503/5513 (LPC Bridge) [1039:0008] (rev b3) 00:01.1 Unknown class [ff00]: Silicon Integrated Systems [SiS] ACPI [1039:0009] 00:01.2 USB Controller [0c03]: Silicon Integrated Systems [SiS] USB 1.1 Controller [1039:7001] (rev 11) 00:02.0 PCI bridge [0604]: Silicon Integrated Systems [SiS] Virtual PCI-to-PCI bridge (AGP) [1039:0001] 00:09.0 Multimedia controller [0480]: Philips Semiconductors TriMedia TM-1300 [1131:5402] (rev 82) 00:0a.0 Ethernet controller [0200]: Intel Corporation 82557/8/9/0/1 Ethernet Pro 100 [8086:1229] (rev 05) 00:0c.0 Multimedia audio controller [0401]: C-Media Electronics Inc CM8738 [13f6:0111] (rev 10) 01:00.0 VGA compatible controller [0300]: Silicon Integrated Systems [SiS] 530/620 PCI/AGP VGA Display Adapter [1039:6306] (rev 2a)
Hi - It has been a while this post got updated, I am not sure though if I should open a new bug though. I compiled kernel 2.6.34 to my needs for the VIA Epia PX5000EG board. Unfortunately even with this kernel version I run at this stage in to a broken status of longhaul APIC. When this longhaul issue will be fixed for VIA platforms please? To be specific the exact error reported in dmesg: " longhaul: APIC detected. Longhaul is currently broken in this configuration ". The CPU runs as 500Mhz as it falls back to performance mode instead of ondemand: cat /proc/cpuinfo processor : 0 vendor_id : CentaurHauls cpu family : 6 model : 13 model name : VIA Eden Processor 500MHz stepping : 0 cpu MHz : 500.000 cache size : 128 KB fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 1 wp : yes flags : fpu vme de pse tsc msr pae mce apic sep mtrr pge cmov pat clflush acpi mmx fxsr sse sse2 pni est xtpr rng rng_en ace ace_en ace2 ace2_en phe phe_en pmm pmm_en bogomips : 999.55 clflush size : 64 cache_alignment : 64 address sizes : 36 bits physical, 32 bits virtual power management: lspci -nn 00:00.0 Host bridge [0600]: VIA Technologies, Inc. CX700/VX700 Host Bridge [1106:0324] (rev 10) 00:00.1 Host bridge [0600]: VIA Technologies, Inc. CX700/VX700 Host Bridge [1106:1324] 00:00.2 Host bridge [0600]: VIA Technologies, Inc. CX700/VX700 Host Bridge [1106:2324] 00:00.3 Host bridge [0600]: VIA Technologies, Inc. CX700/VX700 Host Bridge [1106:3324] 00:00.4 Host bridge [0600]: VIA Technologies, Inc. CX700/VX700 Host Bridge [1106:4324] 00:00.7 Host bridge [0600]: VIA Technologies, Inc. CX700/VX700 Host Bridge [1106:7324] 00:01.0 PCI bridge [0604]: VIA Technologies, Inc. VT8237/VX700 PCI Bridge [1106:b198] 00:0f.0 IDE interface [0101]: VIA Technologies, Inc. VX800 Serial ATA and EIDE Controller [1106:5324] 00:10.0 USB Controller [0c03]: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller [1106:3038] (rev 90) 00:10.1 USB Controller [0c03]: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller [1106:3038] (rev 90) 00:10.2 USB Controller [0c03]: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller [1106:3038] (rev 90) 00:10.4 USB Controller [0c03]: VIA Technologies, Inc. USB 2.0 [1106:3104] (rev 90) 00:11.0 ISA bridge [0601]: VIA Technologies, Inc. CX700/VX700 PCI to ISA Bridge [1106:8324] 00:11.7 Host bridge [0600]: VIA Technologies, Inc. CX700/VX700 Internal Module Bus [1106:324e] 00:13.0 Host bridge [0600]: VIA Technologies, Inc. CX700/VX700 Host Bridge [1106:324b] 00:13.1 PCI bridge [0604]: VIA Technologies, Inc. CX700/VX700 PCI to PCI Bridge [1106:324a] 01:00.0 VGA compatible controller [0300]: VIA Technologies, Inc. CX700/VX700 [S3 UniChrome Pro] [1106:3157] (rev 03) 02:06.0 Ethernet controller [0200]: VIA Technologies, Inc. VT6105/VT6106S [Rhine-III] [1106:3106] (rev 8b)
So sad to see this ticket marked obsolete today. I really like this machine.